Five SO4^2-/TiO2-MXOY solid super acids(SSA:Cu@Ti:SSA,Zr@Ti:SSA,Fe@Ti:SSA,Mn@Ti:SSA,Mo@Ti:SSA)were successfully prepared by sol-gel method,and its chemical structure and element content were characterized by X-ray dif...Five SO4^2-/TiO2-MXOY solid super acids(SSA:Cu@Ti:SSA,Zr@Ti:SSA,Fe@Ti:SSA,Mn@Ti:SSA,Mo@Ti:SSA)were successfully prepared by sol-gel method,and its chemical structure and element content were characterized by X-ray diffraction(XRD)analysis,Fourier transform infrared spectroscopy(FHIR)and energy dispersive spectroscopy(EDS).Then,a compound flame retardant system containing SSA and ammonium polyphosphate/montmorillonite(AM)were was introduced into an unsaturated polyester resin(UPR)to enhance the flame retardance.The effect of SSA on the flammability and thermal stability of the UPR was evaluated by the limiting oxygen index(LOI),cone calorimeter te st(CCT)and thermogravimetric analysis(TGA).The LOI results showed that the flame retardance of the UPR composites was significantly improved with the addition of SSA.Moreover,their heat release rate(HRR),total heat release(THR),the smoke production rate(SPR)and CO and CO2 yield were much decreased.In addition,the initial decomposition temperature of UPR/AM/S SA was delayed,indicating that their thermal stability was increased,and the residual char of UPR/AM/SSA was also increa sed due to strong catalytic of SSA ability for esterification and dehydration.Furthermore,the microstructure of the residual char after combustion of the UPR composites was studied by the scanning electron microscopy(SEM),and it was found that the char layer structure was more continuous and dense after the addition of the SSA.In sum up,the synergistic effect between SSA and AM was the main factor for the great improvement of flame retardant of UPR composites.展开更多
The water collector is operated in the humid and hot environment of the cooling tower all the year round.It also needs to carry part of the weight of water and silt.Therefore,it is particularly critical to optimize th...The water collector is operated in the humid and hot environment of the cooling tower all the year round.It also needs to carry part of the weight of water and silt.Therefore,it is particularly critical to optimize the material of the water collector and improve its mechanical properties.Polyester,a general term of polymer obtained from polyols and polyacids,is a kind of engineering plastics with excellent properties and wide applications.Glass fiber is a reinforced plastic reinforcement material,and the biggest characteristic of it is the high tensile strength and good heat resistance.In this paper,glass fiber reinforced polyester resin composite material is prepared,its tensile properties and bending properties are tested,and the performance of the imported material JK2020B is compared and analyzed.The results show that the elastic modulus along the fiber direction is relatively high,but the interlayer force in the direction of thickness and width is very small.This review provides a guidance for production process.展开更多
Acrylate modified polyurethane resin was first synthesized, and interpenetrated with unsaturated polyester resin to form IPNs and gradient IPNs which cured at room temperature. The polymerization process was traced by...Acrylate modified polyurethane resin was first synthesized, and interpenetrated with unsaturated polyester resin to form IPNs and gradient IPNs which cured at room temperature. The polymerization process was traced by an IR spectroscopy technique and the simultaneous interpenetrating techniques were determined. The morphology of these IPNs were estimated by TMA and TEM methods. The results indicated that large amount of interpenetrating and entanglement make T g linked up effectively, and domains between two phases can be in nanometre ranges, which changed with composition ratios. The mechanical properties results showed that IPNs varied from elastomeric to plastic materials. It was noteworthy that, with the introduction of modified groups and the formation of graft construction in IPNs, the miscibility in the systems was improved a lot. These further led to the improved mechanical properties of IPNs with elastomer reinforced and plasticizer toughened as well. The reinforced miscibility between the networks can apparently change mechanical property especially for the gradient ones when the materials are elongated.展开更多
The synthesis of reaction flame retarding unsaturated polyester resin and the flame retarding mechanism are investigated.By taking the synthesis flame retarding unsaturated polyester resin as a base material,glass fib...The synthesis of reaction flame retarding unsaturated polyester resin and the flame retarding mechanism are investigated.By taking the synthesis flame retarding unsaturated polyester resin as a base material,glass fibers as reinforced material,under the condition of adding graphite or carbon black respectively,the composites were manufactured.The flame retarding and antistatic properties are also studied.In the experiment,bromide-bearing flame retarding resin decomposed under a high temperature.Compound HBr was set out and retarded or stopped the flame.High concentration of HBr gas wall was formed between gas and solid phrases,which decreased flame.The results show that antistatic property of carbon black is higher than that of graphite.Adding a threshed value of 1% carbon black into composite,the antistatic property is at its highest value.展开更多
HDI trimer was firstly used to improve the mechanical properties of hydroxylterminated unsaturated polyester (UP). Mechanical properties measurements performed on the cured materials demonstrate a distinct improvement...HDI trimer was firstly used to improve the mechanical properties of hydroxylterminated unsaturated polyester (UP). Mechanical properties measurements performed on the cured materials demonstrate a distinct improvement in intensity and toughness in the presence of HDI trimer and shows the change trends of increase and then decrease. The morphological analysis of the fracture surfaces shows that the micro-phase separated structures appear in modified UPR systems and changed from dendritric, dimple and to cystiform structures with the increase of HDI trimer content. The presence of the cystiform structures made the modified UPR systems present the best properties.展开更多
The reduction action mechanism of unsaturated polyester resin reducer is analysed. The experimental results show that the active reducer bearing reactive functional group on the ends of molecules effectively lowers th...The reduction action mechanism of unsaturated polyester resin reducer is analysed. The experimental results show that the active reducer bearing reactive functional group on the ends of molecules effectively lowers the curing shrinkage of unvaturated polyester resin.展开更多
The reduction action mechanism of the unsatrurated polyester resin reducer is analysed by the free space volume theory. Through measuring the reduction magnitude in each phase of solidification, the authors predicted ...The reduction action mechanism of the unsatrurated polyester resin reducer is analysed by the free space volume theory. Through measuring the reduction magnitude in each phase of solidification, the authors predicted the rate of reduction is in concordance with the results from experiments. From this we presented corresponding solutions to different causes of the reduction action of the unsatwated polyester resin.展开更多
The nano-TiO2/unsaturated polyester resin (referred to as nano-TiO2/UPR hereafter) was prepared with the 'reaction method', by which a chemical bond generated between nano-TiO2 and UP was inserted in the UP lo...The nano-TiO2/unsaturated polyester resin (referred to as nano-TiO2/UPR hereafter) was prepared with the 'reaction method', by which a chemical bond generated between nano-TiO2 and UP was inserted in the UP long chain. The performance of the nano-TiO2/UPR was determined by such a new structure. The research results showed that the reactivity of nano-TiO2/UPR is higher than that of UPR. The impact strength and bending strength of nanoTiO2/UPR are greatly enhanced as compared with that of UPR. Thermal resistance and dielectric property of nano-TiO2/UPR are the same as that of UPR.展开更多
The morphology,mechanical properties of unsaturated polyester(UP)resin modified with TDI were studied via dynamic FT-IR spectra,SEM,DMA and mechanical property testing.Results show that companying with the cured cross...The morphology,mechanical properties of unsaturated polyester(UP)resin modified with TDI were studied via dynamic FT-IR spectra,SEM,DMA and mechanical property testing.Results show that companying with the cured cross-linking reaction of UP resin,TDI can firstly react with UP and produce polyurethane(PU),and then UP and PU form the cross-linking nets together.The impact fracture section morphology of modified UP resin manifested the typical sea-islands structure.Testing of mechanical properties showes that for introducing of PU,the TDI has an obvious effect on the toughness and strength of UP resin. When the ratio of TDI/UP(w/w)was 7.5%,the modified UP resin exhibited the best mechanical properties with flexural strength of 125 MPa,impact strength of 18 kJ·m-2 and tensile strength of 72 MPa.展开更多
This study aims to evaluate the erosion behavior and the hardness of hybrid composites made of varying amounts of coconut shells,walnut shells,and carbonfibers dispersed in a polyester matrix.MINITAB(L16)Taguchi experi...This study aims to evaluate the erosion behavior and the hardness of hybrid composites made of varying amounts of coconut shells,walnut shells,and carbonfibers dispersed in a polyester matrix.MINITAB(L16)Taguchi experiments were used to determine the optimal combination of parameters.In particular,an erosion device con-sisting of a motor with a constantflow rate of 45 L/min,a pump with a diameter of 40 mm,a nozzle with a dia-meter of 5 mm,and a tank made of“perspex glass”55 cm long,30 cm tall,and 25 cm wide was used.The tests were conducted by varying the sample-to-nozzle distance,the pattern angle,and the sand particle size.The results have revealed that the presence of 7.5%by weight of waste coconut shell,for conditions corresponding to 90°angle,sand size 425μm,stand distance 30 cm,gives the best wear resistance(3.04×10^(-5) g/g).Thefiller content and sand particle size affect the erosive rate,with the angle playing a secondary role.The distance between the sample and the nozzle has a weaker effect on erosive wear.The hardness results show that the models(UP-5%carbonfiber-2.5-3.5-4.5-5.5-6.5-7.5 wt.%waste coconut shell)give the best values for prayer compared to the samples(UP-5 wt.%carbonfiber-2.5-3.5-4.5-5.5-6.5-7.5 wt.%waste walnut shell).展开更多
Nano-silica treated with different kinds of coupling agent(KH550, A-143, A-151) was used to modify the surface condition of glass fiber, and then, the modified glass fiber/ unsaturated polyester resin(UPR) composites ...Nano-silica treated with different kinds of coupling agent(KH550, A-143, A-151) was used to modify the surface condition of glass fiber, and then, the modified glass fiber/ unsaturated polyester resin(UPR) composites materials were prepared. Scanning electron microscopy(SEM), dynamic mechanical analysis(DMA), and impact test were used to characterize the composite materials' structure and properties. The morphology of composite materials shows that the adhesion between nano-silica and glass fiber is improved when silane coupling agent is added in. The DMA and impact test results show that silane coupling agent(especially KH550 and A-151) could effectively improve the composite's mechanical properties. When the dose of KH550 was 0.1%(m ︰m), the storage modulus and impact strength reached the maximum.展开更多
1 Introduction In the GRP (Glass fibre Reinforced Product) industry Cobalt Octoate is the promoter of choice for cross-linking unsaturated polyester (UPE) and styrene monomer.UPE's are often prepared to contain a ...1 Introduction In the GRP (Glass fibre Reinforced Product) industry Cobalt Octoate is the promoter of choice for cross-linking unsaturated polyester (UPE) and styrene monomer.UPE's are often prepared to contain a concentration of 0.04%-0.05% of Cobalt ions so that faster cross-linking of the resin is achieved and ultimately faster manufacturing of the GRP component is achieved.These products sometimes fail prematurely after being manufactured and dispatched to the end user.The influence of Cobalt Octoat...展开更多
The global polyester resin dispersion market size is anticipated to reach a valuation of US$7,635.4 million by 2023.It is projected to witness a CAGR of 4.8%in the estimated time period from 2023 to 2033.A valuation o...The global polyester resin dispersion market size is anticipated to reach a valuation of US$7,635.4 million by 2023.It is projected to witness a CAGR of 4.8%in the estimated time period from 2023 to 2033.A valuation of around US$12,200.7 million is predicted for the global market by 2033.展开更多
Curing behaviors of the unsaturated polyester resin (UPR) containing 1-1.8 wt% methyl ethyl ketone peroxide (MEKP) initiator are investigated. The viscosity, gelation and vitrification transition of the UPR-MEKP syste...Curing behaviors of the unsaturated polyester resin (UPR) containing 1-1.8 wt% methyl ethyl ketone peroxide (MEKP) initiator are investigated. The viscosity, gelation and vitrification transition of the UPR-MEKP systems are examined using the rotating viscometer and differential scanning calorimetry (DSC). A liquid fragility parameter, Mc , defined as the viscosity variation rate of the liquids towards the curing temperature is presented. It is found that Mc has a good negative relation with the glass transition temperature (Tg ) in the systems. Mc can be used for predicting the stability of the cured amorphous systems. The relationship between the liquid and cured thermoset polymer systems is studied from both the thermodynamic and kinetic point of view.展开更多
On July 10th,Reichhold signed a letter of intend with Tianjin Economic Technology Develop-ment Zone (TETDZ) on production of unsaturated polyester resins.Reichhold intends to spend US$40 million to build an unsaturate...On July 10th,Reichhold signed a letter of intend with Tianjin Economic Technology Develop-ment Zone (TETDZ) on production of unsaturated polyester resins.Reichhold intends to spend US$40 million to build an unsaturated polyester resins plant at Tanggu,TETDZ.The proposed plant is expected to produce 50 thousand tons of展开更多
Unsaturated polyester resin (UPR)/acrylate-terminated polyurethane (ATPU)/organo-modified montmorillonite (OMMT) nanocomposites were prepared by the in situ intercalative polymerization method. Samples were prepared b...Unsaturated polyester resin (UPR)/acrylate-terminated polyurethane (ATPU)/organo-modified montmorillonite (OMMT) nanocomposites were prepared by the in situ intercalative polymerization method. Samples were prepared by the sequential mixing, i.e. mixture of the ATPU and styrene (S) and OMMT were prepared in the first step; UPR was then added to the pre-intercalates of ATPU/S/OMMT. Results indicate that the mechanical properties and thermal properties of UPR/ATPU/OMMT nanocomposites greatly depend on the amount of ATPU and OMMT. Results show that the addition of ATPU could increase the impact strength of UPR/ATPU composites, but the tensile strength, flexural strength and heat resistance of the materials are obviously decreased. When the weight ratio between UPR, ATPU and OMMT were 82:15:3,the impact strength and heat distortion-temperature of nanocomposite were greatly improved, meanwhile there was little change for other properties of the nanocomposites. The synergistic enhancement effects of ATPU and OMMT on the composites were observed. The structures and morphology of the composites were investigated by X-ray diffraction,scanning electron microscopy and transmission electron microscopy.展开更多
In this study, jute woven fabrics (1 × 1 plain, twill, zigzag and diamond weave) were manufactured from 100% raw jute yarn. The fabric specimens were treated by 5%, 10%, 15%, 20% and 25% unsaturated polyester res...In this study, jute woven fabrics (1 × 1 plain, twill, zigzag and diamond weave) were manufactured from 100% raw jute yarn. The fabric specimens were treated by 5%, 10%, 15%, 20% and 25% unsaturated polyester resin where styrene monomer used as a solvent and 1% methyl ethyl ketone peroxide (MEKP) was used as initiator. Two bar pressure was applied for complete wetting of the fabric by a Padder and curing was done at 130?C for 10 minutes. The physico-mechanical characteristics of untreated and treated samples were examined and evaluated. It was revealed that moisture content (MC) and water absorbency of the treated specimens were decreased with the increase of resin percentage (%) in the fabrics. MC and water absorbency were maximum decreased up to 50.23% and 60.14% respectively by 25% resin treatment. On the other hand, bending length (BL), flexural rigidity (FR), flexural modulus (FM) and tensile strength (TS) were enhanced with the increase of resin percentage in the fabrics which resulted higher fabric stiffness. The maximum improvement of BL, FR, FM and TS were found to be 6.67%, 56.04%, 10.57% and 18.75% respectively in comparison to untreated sample. Soil degradation tests exhibited that 33.59% TS loss occurred for untreated specimens where only 8.04% loss of TS found for 25% resin treated one. Furthermore, jute based twill, zigzag and diamond fabrics were also treated by 10%, 15%, 20% and 25% resin, then measured their TS and compared with plain fabrics. It was revealed that plain fabrics have superior TS over other fabrics. It was also evident that TS enhanced for all the fabrics after resin treatment and maximum increase found for all the fabrics up to 25% resin treatment.展开更多
The synthesis and characterization of hyperbranched polyester (HBP) with different molecular weight are studied. The effect of HBP on the modification of epoxy resins cured with anhydride is mainly discussed. The char...The synthesis and characterization of hyperbranched polyester (HBP) with different molecular weight are studied. The effect of HBP on the modification of epoxy resins cured with anhydride is mainly discussed. The characteristics of HBP and the morphologies of cured system are determined by nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC) and scanning electron microscope (SEM). The impact strength of cured system is detected and Fourier transform infrared (FTIR) measurements were used to pursue the curing process. The investigation shows that HBP can improve the toughness by forming copolymer networks between epoxy resins, HBP and anhydride. Moreover, when the molecular weight of HBP is 1342g/mol the toughening effect is the best, and the changes of toughness are small with the increase of molecular weight of HBP to 3500 g/mol.展开更多
The influences of various kinds of UV-absorbers,antioxidants and their mixtures on UV-aging resis-tance of transparent unsaturated polyester FRP arestudied by artificial aocelerating aging test.Theresults show that th...The influences of various kinds of UV-absorbers,antioxidants and their mixtures on UV-aging resis-tance of transparent unsaturated polyester FRP arestudied by artificial aocelerating aging test.Theresults show that the UV-aging resistance of com-bined stabilizers is better than single stabilizer.It is concluded that the cooperative effect of UV-absorbers is caused bg the increase of wave leng-th and intensity of the absorption light the coopora-tive effect of UV-absorbers and antioxidants iscaused by Dreventing the photo-oxidantion.展开更多
The synthesis process of organic montmorillonite was designed and some kinds of montmorillonite/unsaturated polyester composites using different interlayer spacing montmorillonite were prepared. The interlayer spacing...The synthesis process of organic montmorillonite was designed and some kinds of montmorillonite/unsaturated polyester composites using different interlayer spacing montmorillonite were prepared. The interlayer spacing of montmorillonite was investigated by XRD and was increased to 3.98nm. The relationship between the four influential factors and the interlayer spacing were regressively analyzed and the mathematical model was established, and the result shows when the content of organic reagent was less than 70%, the relationship between the interlayer spacing and the content was linear as follows: interlayer spacing=1.771+2.828×concentration, the effect of the other factors was not significant. Additionally, the testing of mechanical properties of the composites showed the impact strength was improved by 217%, and the bending strength was improved by 355%, when using the montmorillonite(MMT) of the largest interlayer spacing (3.98 nm).The result of ESEM shows the interface is bonded well when the composite specimen contains the 3.98 nm MMT.展开更多
基金Supported by the National Natural Science Foundation of China(51803057)Hebei Province Science Foundation for Youths(E2019508144)Fundamental Research Funds for the Central Universities(3142017099)。
文摘Five SO4^2-/TiO2-MXOY solid super acids(SSA:Cu@Ti:SSA,Zr@Ti:SSA,Fe@Ti:SSA,Mn@Ti:SSA,Mo@Ti:SSA)were successfully prepared by sol-gel method,and its chemical structure and element content were characterized by X-ray diffraction(XRD)analysis,Fourier transform infrared spectroscopy(FHIR)and energy dispersive spectroscopy(EDS).Then,a compound flame retardant system containing SSA and ammonium polyphosphate/montmorillonite(AM)were was introduced into an unsaturated polyester resin(UPR)to enhance the flame retardance.The effect of SSA on the flammability and thermal stability of the UPR was evaluated by the limiting oxygen index(LOI),cone calorimeter te st(CCT)and thermogravimetric analysis(TGA).The LOI results showed that the flame retardance of the UPR composites was significantly improved with the addition of SSA.Moreover,their heat release rate(HRR),total heat release(THR),the smoke production rate(SPR)and CO and CO2 yield were much decreased.In addition,the initial decomposition temperature of UPR/AM/S SA was delayed,indicating that their thermal stability was increased,and the residual char of UPR/AM/SSA was also increa sed due to strong catalytic of SSA ability for esterification and dehydration.Furthermore,the microstructure of the residual char after combustion of the UPR composites was studied by the scanning electron microscopy(SEM),and it was found that the char layer structure was more continuous and dense after the addition of the SSA.In sum up,the synergistic effect between SSA and AM was the main factor for the great improvement of flame retardant of UPR composites.
文摘The water collector is operated in the humid and hot environment of the cooling tower all the year round.It also needs to carry part of the weight of water and silt.Therefore,it is particularly critical to optimize the material of the water collector and improve its mechanical properties.Polyester,a general term of polymer obtained from polyols and polyacids,is a kind of engineering plastics with excellent properties and wide applications.Glass fiber is a reinforced plastic reinforcement material,and the biggest characteristic of it is the high tensile strength and good heat resistance.In this paper,glass fiber reinforced polyester resin composite material is prepared,its tensile properties and bending properties are tested,and the performance of the imported material JK2020B is compared and analyzed.The results show that the elastic modulus along the fiber direction is relatively high,but the interlayer force in the direction of thickness and width is very small.This review provides a guidance for production process.
文摘Acrylate modified polyurethane resin was first synthesized, and interpenetrated with unsaturated polyester resin to form IPNs and gradient IPNs which cured at room temperature. The polymerization process was traced by an IR spectroscopy technique and the simultaneous interpenetrating techniques were determined. The morphology of these IPNs were estimated by TMA and TEM methods. The results indicated that large amount of interpenetrating and entanglement make T g linked up effectively, and domains between two phases can be in nanometre ranges, which changed with composition ratios. The mechanical properties results showed that IPNs varied from elastomeric to plastic materials. It was noteworthy that, with the introduction of modified groups and the formation of graft construction in IPNs, the miscibility in the systems was improved a lot. These further led to the improved mechanical properties of IPNs with elastomer reinforced and plasticizer toughened as well. The reinforced miscibility between the networks can apparently change mechanical property especially for the gradient ones when the materials are elongated.
文摘The synthesis of reaction flame retarding unsaturated polyester resin and the flame retarding mechanism are investigated.By taking the synthesis flame retarding unsaturated polyester resin as a base material,glass fibers as reinforced material,under the condition of adding graphite or carbon black respectively,the composites were manufactured.The flame retarding and antistatic properties are also studied.In the experiment,bromide-bearing flame retarding resin decomposed under a high temperature.Compound HBr was set out and retarded or stopped the flame.High concentration of HBr gas wall was formed between gas and solid phrases,which decreased flame.The results show that antistatic property of carbon black is higher than that of graphite.Adding a threshed value of 1% carbon black into composite,the antistatic property is at its highest value.
基金Funded by the Hubei Provincial Natural Science Fundation of China(No.2006ABA321)
文摘HDI trimer was firstly used to improve the mechanical properties of hydroxylterminated unsaturated polyester (UP). Mechanical properties measurements performed on the cured materials demonstrate a distinct improvement in intensity and toughness in the presence of HDI trimer and shows the change trends of increase and then decrease. The morphological analysis of the fracture surfaces shows that the micro-phase separated structures appear in modified UPR systems and changed from dendritric, dimple and to cystiform structures with the increase of HDI trimer content. The presence of the cystiform structures made the modified UPR systems present the best properties.
文摘The reduction action mechanism of unsaturated polyester resin reducer is analysed. The experimental results show that the active reducer bearing reactive functional group on the ends of molecules effectively lowers the curing shrinkage of unvaturated polyester resin.
文摘The reduction action mechanism of the unsatrurated polyester resin reducer is analysed by the free space volume theory. Through measuring the reduction magnitude in each phase of solidification, the authors predicted the rate of reduction is in concordance with the results from experiments. From this we presented corresponding solutions to different causes of the reduction action of the unsatwated polyester resin.
文摘The nano-TiO2/unsaturated polyester resin (referred to as nano-TiO2/UPR hereafter) was prepared with the 'reaction method', by which a chemical bond generated between nano-TiO2 and UP was inserted in the UP long chain. The performance of the nano-TiO2/UPR was determined by such a new structure. The research results showed that the reactivity of nano-TiO2/UPR is higher than that of UPR. The impact strength and bending strength of nanoTiO2/UPR are greatly enhanced as compared with that of UPR. Thermal resistance and dielectric property of nano-TiO2/UPR are the same as that of UPR.
基金the Hubei Provincial Natural Science Fundation of China(No.2006ABA321)
文摘The morphology,mechanical properties of unsaturated polyester(UP)resin modified with TDI were studied via dynamic FT-IR spectra,SEM,DMA and mechanical property testing.Results show that companying with the cured cross-linking reaction of UP resin,TDI can firstly react with UP and produce polyurethane(PU),and then UP and PU form the cross-linking nets together.The impact fracture section morphology of modified UP resin manifested the typical sea-islands structure.Testing of mechanical properties showes that for introducing of PU,the TDI has an obvious effect on the toughness and strength of UP resin. When the ratio of TDI/UP(w/w)was 7.5%,the modified UP resin exhibited the best mechanical properties with flexural strength of 125 MPa,impact strength of 18 kJ·m-2 and tensile strength of 72 MPa.
文摘This study aims to evaluate the erosion behavior and the hardness of hybrid composites made of varying amounts of coconut shells,walnut shells,and carbonfibers dispersed in a polyester matrix.MINITAB(L16)Taguchi experiments were used to determine the optimal combination of parameters.In particular,an erosion device con-sisting of a motor with a constantflow rate of 45 L/min,a pump with a diameter of 40 mm,a nozzle with a dia-meter of 5 mm,and a tank made of“perspex glass”55 cm long,30 cm tall,and 25 cm wide was used.The tests were conducted by varying the sample-to-nozzle distance,the pattern angle,and the sand particle size.The results have revealed that the presence of 7.5%by weight of waste coconut shell,for conditions corresponding to 90°angle,sand size 425μm,stand distance 30 cm,gives the best wear resistance(3.04×10^(-5) g/g).Thefiller content and sand particle size affect the erosive rate,with the angle playing a secondary role.The distance between the sample and the nozzle has a weaker effect on erosive wear.The hardness results show that the models(UP-5%carbonfiber-2.5-3.5-4.5-5.5-6.5-7.5 wt.%waste coconut shell)give the best values for prayer compared to the samples(UP-5 wt.%carbonfiber-2.5-3.5-4.5-5.5-6.5-7.5 wt.%waste walnut shell).
基金Supported by the National Natural Science Foundation of of China(J1210061)
文摘Nano-silica treated with different kinds of coupling agent(KH550, A-143, A-151) was used to modify the surface condition of glass fiber, and then, the modified glass fiber/ unsaturated polyester resin(UPR) composites materials were prepared. Scanning electron microscopy(SEM), dynamic mechanical analysis(DMA), and impact test were used to characterize the composite materials' structure and properties. The morphology of composite materials shows that the adhesion between nano-silica and glass fiber is improved when silane coupling agent is added in. The DMA and impact test results show that silane coupling agent(especially KH550 and A-151) could effectively improve the composite's mechanical properties. When the dose of KH550 was 0.1%(m ︰m), the storage modulus and impact strength reached the maximum.
文摘1 Introduction In the GRP (Glass fibre Reinforced Product) industry Cobalt Octoate is the promoter of choice for cross-linking unsaturated polyester (UPE) and styrene monomer.UPE's are often prepared to contain a concentration of 0.04%-0.05% of Cobalt ions so that faster cross-linking of the resin is achieved and ultimately faster manufacturing of the GRP component is achieved.These products sometimes fail prematurely after being manufactured and dispatched to the end user.The influence of Cobalt Octoat...
文摘The global polyester resin dispersion market size is anticipated to reach a valuation of US$7,635.4 million by 2023.It is projected to witness a CAGR of 4.8%in the estimated time period from 2023 to 2033.A valuation of around US$12,200.7 million is predicted for the global market by 2033.
基金the financial support from the National Natural Science Foundation of China ( 50831003)
文摘Curing behaviors of the unsaturated polyester resin (UPR) containing 1-1.8 wt% methyl ethyl ketone peroxide (MEKP) initiator are investigated. The viscosity, gelation and vitrification transition of the UPR-MEKP systems are examined using the rotating viscometer and differential scanning calorimetry (DSC). A liquid fragility parameter, Mc , defined as the viscosity variation rate of the liquids towards the curing temperature is presented. It is found that Mc has a good negative relation with the glass transition temperature (Tg ) in the systems. Mc can be used for predicting the stability of the cured amorphous systems. The relationship between the liquid and cured thermoset polymer systems is studied from both the thermodynamic and kinetic point of view.
文摘On July 10th,Reichhold signed a letter of intend with Tianjin Economic Technology Develop-ment Zone (TETDZ) on production of unsaturated polyester resins.Reichhold intends to spend US$40 million to build an unsaturated polyester resins plant at Tanggu,TETDZ.The proposed plant is expected to produce 50 thousand tons of
基金This research was supported by the Science and Technology Key Project of Guangdong(A1070203).
文摘Unsaturated polyester resin (UPR)/acrylate-terminated polyurethane (ATPU)/organo-modified montmorillonite (OMMT) nanocomposites were prepared by the in situ intercalative polymerization method. Samples were prepared by the sequential mixing, i.e. mixture of the ATPU and styrene (S) and OMMT were prepared in the first step; UPR was then added to the pre-intercalates of ATPU/S/OMMT. Results indicate that the mechanical properties and thermal properties of UPR/ATPU/OMMT nanocomposites greatly depend on the amount of ATPU and OMMT. Results show that the addition of ATPU could increase the impact strength of UPR/ATPU composites, but the tensile strength, flexural strength and heat resistance of the materials are obviously decreased. When the weight ratio between UPR, ATPU and OMMT were 82:15:3,the impact strength and heat distortion-temperature of nanocomposite were greatly improved, meanwhile there was little change for other properties of the nanocomposites. The synergistic enhancement effects of ATPU and OMMT on the composites were observed. The structures and morphology of the composites were investigated by X-ray diffraction,scanning electron microscopy and transmission electron microscopy.
文摘In this study, jute woven fabrics (1 × 1 plain, twill, zigzag and diamond weave) were manufactured from 100% raw jute yarn. The fabric specimens were treated by 5%, 10%, 15%, 20% and 25% unsaturated polyester resin where styrene monomer used as a solvent and 1% methyl ethyl ketone peroxide (MEKP) was used as initiator. Two bar pressure was applied for complete wetting of the fabric by a Padder and curing was done at 130?C for 10 minutes. The physico-mechanical characteristics of untreated and treated samples were examined and evaluated. It was revealed that moisture content (MC) and water absorbency of the treated specimens were decreased with the increase of resin percentage (%) in the fabrics. MC and water absorbency were maximum decreased up to 50.23% and 60.14% respectively by 25% resin treatment. On the other hand, bending length (BL), flexural rigidity (FR), flexural modulus (FM) and tensile strength (TS) were enhanced with the increase of resin percentage in the fabrics which resulted higher fabric stiffness. The maximum improvement of BL, FR, FM and TS were found to be 6.67%, 56.04%, 10.57% and 18.75% respectively in comparison to untreated sample. Soil degradation tests exhibited that 33.59% TS loss occurred for untreated specimens where only 8.04% loss of TS found for 25% resin treated one. Furthermore, jute based twill, zigzag and diamond fabrics were also treated by 10%, 15%, 20% and 25% resin, then measured their TS and compared with plain fabrics. It was revealed that plain fabrics have superior TS over other fabrics. It was also evident that TS enhanced for all the fabrics after resin treatment and maximum increase found for all the fabrics up to 25% resin treatment.
文摘The synthesis and characterization of hyperbranched polyester (HBP) with different molecular weight are studied. The effect of HBP on the modification of epoxy resins cured with anhydride is mainly discussed. The characteristics of HBP and the morphologies of cured system are determined by nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC) and scanning electron microscope (SEM). The impact strength of cured system is detected and Fourier transform infrared (FTIR) measurements were used to pursue the curing process. The investigation shows that HBP can improve the toughness by forming copolymer networks between epoxy resins, HBP and anhydride. Moreover, when the molecular weight of HBP is 1342g/mol the toughening effect is the best, and the changes of toughness are small with the increase of molecular weight of HBP to 3500 g/mol.
文摘The influences of various kinds of UV-absorbers,antioxidants and their mixtures on UV-aging resis-tance of transparent unsaturated polyester FRP arestudied by artificial aocelerating aging test.Theresults show that the UV-aging resistance of com-bined stabilizers is better than single stabilizer.It is concluded that the cooperative effect of UV-absorbers is caused bg the increase of wave leng-th and intensity of the absorption light the coopora-tive effect of UV-absorbers and antioxidants iscaused by Dreventing the photo-oxidantion.
文摘The synthesis process of organic montmorillonite was designed and some kinds of montmorillonite/unsaturated polyester composites using different interlayer spacing montmorillonite were prepared. The interlayer spacing of montmorillonite was investigated by XRD and was increased to 3.98nm. The relationship between the four influential factors and the interlayer spacing were regressively analyzed and the mathematical model was established, and the result shows when the content of organic reagent was less than 70%, the relationship between the interlayer spacing and the content was linear as follows: interlayer spacing=1.771+2.828×concentration, the effect of the other factors was not significant. Additionally, the testing of mechanical properties of the composites showed the impact strength was improved by 217%, and the bending strength was improved by 355%, when using the montmorillonite(MMT) of the largest interlayer spacing (3.98 nm).The result of ESEM shows the interface is bonded well when the composite specimen contains the 3.98 nm MMT.
