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Non-Isothermal Crystallization Kinetics of PET Under Solid State Poly condensation
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作者 Zhou Weihua and Li Liqing (Department of Fiberic Materials, Beijing Institute of Clothing Technology, Beijing)Tang Xinyi (Department of Chemistry, Jilin University, Changchun) 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1991年第4期236-242,共7页
An equation of non-isothermal crystallization kinetics was derived according to a new model and the crystallizations of both the PET samples under solid state polycon-densation and the pre-orientation yarn of high spe... An equation of non-isothermal crystallization kinetics was derived according to a new model and the crystallizations of both the PET samples under solid state polycon-densation and the pre-orientation yarn of high speeding spinning PET were studied with this equation. The results show that there is a good linear relationship between In {-In[1-X(T)]} and lnΦ. The index m in the equation approximately equals to 3 for PET chips and 1. 3 for pre-orientated yarn. At the same temperature, Q(T) decreases with the increase of PET M. W. and the kinetics parameters obtained by Jeziorny' s method indicate that G also decreases with the increase of PET M. W.. Q(T) and Gc show the same varying tendency in the non-isothermal crystallization process. 展开更多
关键词 non-isothermal crystallization kinetics pet
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Non-isothermal crystallization kinetics of Nylon 10T and Nylon 10T/1010 copolymers:Effect of sebacic acid as a third comonomer 被引量:6
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作者 Zhongqiang Wang Guosheng Hu +2 位作者 Jingting Zhang Jiusheng Xu Wenbo Shi 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2017年第7期963-970,共8页
Nylon 10 T and Nylon 10T/1010 samples were synthesized by direct melt polymerization. The non-isothermal crystallization kinetics of Nylon 10 T and Nylon 10T/1010 was investigated by means of differential scanning cal... Nylon 10 T and Nylon 10T/1010 samples were synthesized by direct melt polymerization. The non-isothermal crystallization kinetics of Nylon 10 T and Nylon 10T/1010 was investigated by means of differential scanning calorimetry(DSC). Jeziorny equation and Mo equation were applied to describe the non-isothermal crystallization kinetics of the Nylon 10 T and the Nylon 10T/1010. The activation energies for non-isothermal crystallization were obtained by Vyazovkin's method and Friedman's method, respectively. These results showed that Jeziorny equation and Mo equation well described the non-isothermal crystallization kinetics of the Nylon 10 T and the Nylon 10T/1010. It was found that the values of the activation energy for non-isothermal crystallization of the Nylon 10T/1010 were lower than those of the Nylon 10 T at a given temperature or relative crystallinity degree,which revealed that crystallization ability of the Nylon 10T/1010 was higher. The crystal morphology was observed by means of a polarized optical microscope(POM) and X-ray diffraction(XRD). It was found that the addition of sebacic acid comonomer not only did not change the crystal form of the Nylon 10 T, but also significantly increased the number and decreased the size of spherulites. Comparing with the Nylon 10 T, the crystallization rate was increased with the addition of the sebacic acid comonomer. 展开更多
关键词 Melt polymerization Nylon 10TNylon 10T/1010 Semiaromatic polyamides crystallization kinetics non-isothermal crystallization
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Non-isothermal Crystallization Kinetics of Polyamide 6/Diaminemodified MWNTs Nanocomposite 被引量:3
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作者 Hong Meng Guoxin Sui Guangyou Xie Rui Yang 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2009年第2期145-150,共6页
The non-isothermal crystallization kinetics of polyamide 6/diamine-modified multi-walled carbon nanotube (PA6/D-MWNT) nanocomposite was investigated by differential scanning calorimetry (DSC). The modified Avrami ... The non-isothermal crystallization kinetics of polyamide 6/diamine-modified multi-walled carbon nanotube (PA6/D-MWNT) nanocomposite was investigated by differential scanning calorimetry (DSC). The modified Avrami equation, the Ozawa equation and the combined Avrami/Ozawa equation were employed to analyze the non-isothermal crystallization data. The crystallization activation energies were also evaluated by the Kissinger method. It was found that the combined Avrami/Ozawa equation could successfully describe the non-isothermal crystallization process. The results showed that D-MWNTs not only acted as effective heterogeneous nucleating agents for PA6 and noticeably increased the crystallization temperature of PA6, but also influenced the mechanism of nucleation and crystal growth of PA6 and then reduced the overall crystallization rate of the neat PA6 matrix. The crystallization activation energy for the nanocomposite sample was greater than that of the neat PA6, which indicated that the addition of D-MWNTs hindered the mobility of PA6 chain segments. 展开更多
关键词 non-isothermal crystallization kinetics Carbon nanotubes Polyamide 6
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Non-isothermal crystallization kinetics of reactive microgel/nylon 6 blends 被引量:1
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作者 何敏 宗思琪 +2 位作者 周亚欢 郭怀兵 樊庆春 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第8期1403-1407,共5页
The non-isothermal crystallization kinetics of reactive microgel/nylon 6 blends was investigated by differential scanning calorimetry(DSC). The Mo equation was employed to analyze the non-isothermal crystallization da... The non-isothermal crystallization kinetics of reactive microgel/nylon 6 blends was investigated by differential scanning calorimetry(DSC). The Mo equation was employed to analyze the non-isothermal crystallization data. The crystallization activation energies were also evaluated by the Kissinger method. The results show that the crystallization onset temperature(T onset) and crystallization peak temperature(T p) decrease with the increase of the content of reactive microgel, while ΔT(T onset–T p), the crystallization half-time(t1/2) and the crystallization enthalpy(ΔH c) increase. The required cooling rates of blends are higher than that of neat nylon6 in order to achieve the same relative crystallinity in a unit of time. The crystallization activation energies of the reactive microgel/nylon 6 blends are greater than those of the neat nylon 6. When the content of reactive microgel is 30%, the relative crystallinity(X t) reaches the maximum. 展开更多
关键词 Reactive microgel Nylon 6 non-isothermal crystallization kinetics crystallization activation energy
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Isothermal and Non-Isothermal Crystallization Kinetics of Conductive Polyvinylidene Fluoride/Poly(Ethylene Terephthalate) Based Composites
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作者 Nafaa Athmouni Jianbin Song +1 位作者 Frej Mighri Saïd Elkoun 《Materials Sciences and Applications》 2016年第1期8-19,共12页
This work deals with isothermal and non-isothermal crystallization kinetics of electrically conductive polyvinylidene fluoride/poly(ethylene terephthalate) (PVDF/PET) based composites. It completes our previous work i... This work deals with isothermal and non-isothermal crystallization kinetics of electrically conductive polyvinylidene fluoride/poly(ethylene terephthalate) (PVDF/PET) based composites. It completes our previous work in which we related the crystallinity of these conductive PVDF/PET based composites to their through-plane resistivity [1]. Isothermal crystallization was described using the logarithmic form of the Avrami equation and it was observed that the crystallization rate of the PVDF phase inside the composite became slower compared to that of neat PVDF. In non-isothermal crystallization, the Avrami exponent of PVDF phase did not show any noticeable variation;however, that of PET phase, which contains the major part of the conductive carbon black (CB) and graphite (GR) additives, showed an evident decrease compared with neat PET. It was also observed that, at the same cooling rate, the crystallization rate of PVDF and PET phases inside the composite was slower than that of neat PVDF and PET. 展开更多
关键词 Isothermal crystallization non-isothermal crystallization PVDF pet crystallization kinetics Avrami Model Bipolar Plate
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Non-isothermal Crystallization Kinetics of Kaolin Modified Polyester
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作者 张瑞欣 陈国强 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第5期945-949,共5页
Fiber-class modified kaolin and PET have been blended in the twin-screw and granulated to chips containing 4 wt% of kaolin.Non-isothermal crystallization process of kaolin modified polyester was investigated using a d... Fiber-class modified kaolin and PET have been blended in the twin-screw and granulated to chips containing 4 wt% of kaolin.Non-isothermal crystallization process of kaolin modified polyester was investigated using a differential scanning calorimetry (DSC),and the addition of kaolin enhances either the melting temperature (Tm) or the crystallization temperature (Tc).The morphology of kaolin modified polyester,the melt of which is cooled at different cooling rate,was observed by scanning electron microscope (SEM).The relationship between Tc and cooling rate F was studied.Semi-crystalline phase t1/2 makes an exponential decline with increasing F,and the higher the cooling rate,the shorter the time of crystallization completion.Non-isothermal crystallization kinetics parameters and the activation energy were calculated,indicating that the higher rate of cooling needs the higher relative crystallinity in the unit crystallization time,the crystallization rate increased while speeding up the temperature reduction,and the activation energy ΔE was calculated to be-204.1566 kJ/mol for the non-isothermal crystallization processes by the Kissinger's methods. 展开更多
关键词 KAOLIN POLYESTER crystallization kinetics non-isothermal
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Exploring the effect of cooling rate on non-isothermal crystallization of copolymer polypropylene by fast scanning calorimetry
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作者 Yang Liao Ye-yuan Hu +4 位作者 Kosuke Ikeda Ryoji Okabe Rui-fen Wu Ryota Ozaki Qing-yan Xu 《China Foundry》 SCIE EI CAS CSCD 2024年第4期379-386,共8页
Polypropylene is commonly used as a binder for ceramic injection molding,and rapid cooling is often encountered during processing.However,the crystallization behavior of polypropylene shows a strong dependence on cool... Polypropylene is commonly used as a binder for ceramic injection molding,and rapid cooling is often encountered during processing.However,the crystallization behavior of polypropylene shows a strong dependence on cooling rate due to its semi-crystalline characteristics.Therefore,the influence of cooling rate on the quality of final product cannot be ignored.In this study,the fast differential scanning calorimetry(FSC)test was performed to study the influence of cooling rate on the non-isothermal crystallization behavior and non-isothermal crystallization kinetics of a copolymer polypropylene(PP BC03B).The results show that the crystallization temperatures and crystallinity decrease as the cooling rate increases.In addition,two exothermic peaks occur when cooling rate ranges from 30 to 300 K·s^(-1),indicating the formation of another crystal phase.Avrami,Ozawa and Mo equations were used to explore the non-isothermal crystallization kinetics,and it can be concluded that the Mo method is suitable for this study. 展开更多
关键词 cooling rate crystallization temperature crystalLINITY non-isothermal crystallization kinetics FSC copolymer polypropylene
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Non-isothermal Crystallization Kinetics of Modified Poly(ethylene terephthalate) with Ultraviolet Protection
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作者 滕翠青 《Journal of Donghua University(English Edition)》 EI CAS 2002年第1期56-59,共4页
The non-isothermal crystallization kinetics of modified poly(ethylene terephthalate) (PET) with the function of ultraviolet (UV) protection was studied by means of differential scanning calorimetry. The kinetics of th... The non-isothermal crystallization kinetics of modified poly(ethylene terephthalate) (PET) with the function of ultraviolet (UV) protection was studied by means of differential scanning calorimetry. The kinetics of the modified polymer under non-isothermal crystallization was analyzed by Ozawa equation. The crystallization behavior of the modified polymer obeyed Ozawa theory. The additives in the polymer whose function was UV-resistant acted as crystal nucleus in the processing of crystallization, which resulted in the increase of Avrami index and the crystallization rate of the cooling system. 展开更多
关键词 poly(ethylene terephthalate) non-isothermal crystallization kinetics ultraviolet-resistant fibers.
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Non-isothermal Melt Crystallization Kinetics of Anhydrite-Filled Polypropylene Composites 被引量:1
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作者 王少会 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2010年第1期12-19,共8页
The non-isothermal crystallization kinetics of polypropylene (PP), PP/anhydrite composites were investigated by differential scanning calorimetry (DSC) with various cooling rates. The Avrami analysis modified by J... The non-isothermal crystallization kinetics of polypropylene (PP), PP/anhydrite composites were investigated by differential scanning calorimetry (DSC) with various cooling rates. The Avrami analysis modified by Jeziorny and a method developed by Mo were employed to describe the non-isothermal crystallization process of these samples. The difference in the exponent n between PP and PP/anhydrite composites indicated that non-isothermal kinetic crystallization corresponded to tri-dimensional growth with heterogeneous nucleation. The values of half-time, Zc and F(T) showed that the crystallization rate increased with the increasing of cooling rates for PP and PP/anhydrite composites, but the crystallization rate of PP/anhydrite composites was faster than that of PP at a given cooling rate. The method developed by Ozawa did not describe the non-isothermal crystallization process of PP very well. Moreover, the method proposed by Kissinger was used to evaluate the activation energy of the mentioned samples. The result showed that the activation energy of PP/anhydrite was greatly larger than that of PP. 展开更多
关键词 POLYPROPYLENE ANHYDRITE COMPOSITES non-isothermal crystallization kinetics
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KINETICS OF NON-ISOTHERMAL CRYSTALLIZATION 被引量:1
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作者 张志英 曹振林 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1990年第2期142-148,共7页
A kinetic equation of non-isothermal crystamzation was derived by extending Avrami's equation to the non-isothermal situation. More crystallization information can be obtained from this kinetic equation. The curve... A kinetic equation of non-isothermal crystamzation was derived by extending Avrami's equation to the non-isothermal situation. More crystallization information can be obtained from this kinetic equation. The curves of non-isothermal and isothermal crystallizations were analysed and compared for poly (ethylene terephthalate) (PET), and the results were discussed. 展开更多
关键词 non-isothermal crystallization crystallization kinetics Poly (ethyene terephthalate) Differential scanning calorimeter (DSC).
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KINETICS OF NON-ISOTHERMAL CRYSTALLIZATION OF POLY (ETHYLENE TEREPHTHALATE) MODIFIED BY POLY (ETHYLENE GLYCOL)
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作者 张志英 吴世臻 +1 位作者 杜莹华 曹振林 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1991年第4期318-325,共8页
The non-isothermal crystallization kinetics of poly(ethylene terephthalate) (PET) modified by poly (ethlene glycol) (PEG) were determined by DSC. The dual linear regression method was used to evaluate the relationship... The non-isothermal crystallization kinetics of poly(ethylene terephthalate) (PET) modified by poly (ethlene glycol) (PEG) were determined by DSC. The dual linear regression method was used to evaluate the relationship between the reciprocal of t 1/2 ( the half life of crystallization) and the appropriate temperature variable. The parameters such as the activation energy (Ed) for transport, the equilibrium melting temperature (T_m^0),the nucleation parameter (ψ),themaximum crystallization temperature (T_(e, max)), and the kinetic crystallizability (G) for the copolyesters were obtained. The influence of the PEG content in PET chains on the parameters characterizing crystallization kinetics and crystallization thermodynamics was discussed. 展开更多
关键词 Poly (ethylene glycol)/Poly (ethylene terephthalate) copolyester non-isothermal crystallization crystallization kinetics Differential scanning calorimetry (DSC)
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KINETICS OF NON-ISOTHERMAL CRYSTALLIZATION OF NYLON-1010
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作者 Xiao Fu XUE Bao Quan YANG Zhi Shen Mo Laboratory of Polymer Phys. Changchun Institute of Applied Chemistry, Academia Sinica, Changchun, 130022 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第6期483-484,共2页
The kineties of non-isothermal crystallization of Nylon-1010 has been investigated by using differential scanning calorimetry(DSC), DSC curves were obtained under cooling rate(R): 2. 5, 5, 10, 20, 40K/min. Applying Ma... The kineties of non-isothermal crystallization of Nylon-1010 has been investigated by using differential scanning calorimetry(DSC), DSC curves were obtained under cooling rate(R): 2. 5, 5, 10, 20, 40K/min. Applying Mandelkern and Ziabicki theories, the values of the Z kinetic parameter and G the kinetic crystalllzab- ility have been determined. Expenents of Avrami obtained in this work decrease with increase of cooling rate and then level off. The experimental results show disagreements with the Ozawa equation. 展开更多
关键词 NYLON RATE kinetics OF non-isothermal crystallization OF NYLON-1010
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THE NON—ISOTHERMAL CRYSTALLIZATION KINETICS OF A LIQUID CRYSTALLINE RANDOM COPOLYESTER WITH DIFFERENT COMPOSITIONS
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作者 董炎明 李志敏 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1994年第1期44-48,共5页
The non-isothermal crystallization kinetics analysis of liquid crystalline random copolyestercomposed of p-oxybenzoate (B) and 2, 6-oxynaphthoate (N) monomers was carried out by meansof differential scanning calorimet... The non-isothermal crystallization kinetics analysis of liquid crystalline random copolyestercomposed of p-oxybenzoate (B) and 2, 6-oxynaphthoate (N) monomers was carried out by meansof differential scanning calorimetry basing on Ziabicki and Jeziorny method. Although the compo-sition of 58/42 B-N copolyester had poorer thermodynamic crystallizability comparing with thoseof 30/70 and 75/25, its kinetic crystallizability Go was slightly larger. This fact was due to thepoorer match of sequences of 58/42 B-N in domains of nematic melt,and therefore better mobilityof chains during crystallization. The Avrami exponents of three composition species were allabout 2. 5, implying two dimensional growth in so-called non-periodic layer crystallites and a mixture of homogeneous and heterogeneous nucleation. 展开更多
关键词 Liqiud crystalline COPOLYESTER non-isothermal crystallization kinetics Avrami exponent
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EFFECT OF N,N,N'N'-TETRAALKYL TEREPHTHALAMIDE ON NONISOTHERMAL CRYSTALLIZATION KINETICS OF POLYPROPYLENE
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作者 申屠宝卿 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2006年第4期345-351,共7页
The effect of N,N,N',N'-tetraalkyl terephthalamide (TATA) on the non-isothermal crystallization and melting characteristics ofpolypropylene (PP) was studied. The addition of TATA can lead to the formation ofβ-c... The effect of N,N,N',N'-tetraalkyl terephthalamide (TATA) on the non-isothermal crystallization and melting characteristics ofpolypropylene (PP) was studied. The addition of TATA can lead to the formation ofβ-crystal PP. With the increase in TATA concentration the degree of crystallinity for β-crystal PP increased significantly, and that for a-crystal PP decreased, which indicated that TATA effectively induced the formation of β-crystal PP. WAXD also revealed the existence of β-crystal PP after the introduction of TATA into PP. PP containing TATA crystallized at a temperature range of 5-10℃ higher than that of pure PP, and the half-crystallization time (t1/2) and Avrami exponent (n) of PP at the same cooling rate were decreased by the addition of TATA, indicating that TATA influenced the crystallization rate and crystallization growth mode of PP. The rate constant of crystallization of PP containing TATA (Zc) was larger than that of pure PP, which further indicated that the crystallization of PP was accelerated by the addition of TATA. 展开更多
关键词 POLYPROPYLENE N N N' N'-tetraalkyl terephthalamide non-isothermal crystallization kinetics β-crystal.
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An Efficient Organic Additive to Control the Crystallization Rate of Aliphatic Polyketone: A Non-isothermal Crystallization Kinetics Study 被引量:4
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作者 He-xin Zhang Min-Jeong Park +3 位作者 Young-Kwon Moon Eun-Bin Ko Xue-quan Zhang Keun-Byoung Yoon 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2017年第4期547-557,共11页
Three types of organic compounds--two carboxylic acids and an anhydride, were used as additives for polyketone (PK). The effect of the additive structure and their feed ratios on the melting temperature, crystalliza... Three types of organic compounds--two carboxylic acids and an anhydride, were used as additives for polyketone (PK). The effect of the additive structure and their feed ratios on the melting temperature, crystallization temperature, and crystallization rate of PK were studied. We found that the crystallization temperature could be reduced significantly by introducing a small quantity of organic additive, in particular, an anhydride. On addition of 1 phr of anhydride, the crystallization temperature was reduced by 10.7 ℃. Therefore, the non-isothermal crystallization kinetics of aliphatic PKJanhydride blends with various feed ratios was investigated using DSC. The results were analyzed by various theoretical models, such as Avrami, Ozawa and combined Avrami-Ozawa models. 展开更多
关键词 POLYKETONE ANHYDRIDE non-isothermal crystallization kinetics
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Magnetic properties and crystallization kinetics of Zn_(0.5) Ni_(0.5) Fe_2O_4
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作者 WU Wenwei CAI Jinchao WU Xuehang LI Yongni LIAO Sen 《Rare Metals》 SCIE EI CAS CSCD 2011年第6期621-626,共6页
Precursor of nanocrystalline Zno.sNio.sFe2O4 was obtained by grinding mixture of ZnSO4.7H2O, NiSO4.6H2O, FeSO4.7H2O, and Na2CO3.10H2O under the condition of suffactant polyethylene glycol (PEG)-400 being present at ... Precursor of nanocrystalline Zno.sNio.sFe2O4 was obtained by grinding mixture of ZnSO4.7H2O, NiSO4.6H2O, FeSO4.7H2O, and Na2CO3.10H2O under the condition of suffactant polyethylene glycol (PEG)-400 being present at room temperature, washing the mixture with water to remove soluble inorganic salts and drying it at 373 K. The spinel Zn0.5Ni0.5Fe2O4 was obtained via calcining precursor above 773 K. The precursor and its calcined products were characterized by differential scanning calorimetry (DSC), Fourier transform infrared (FF-IR), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The result showed that Zn0.sNio.sFe204 obtained at 1073 K had a saturation magnetization of 74 A.mLkg-1. Kinetics of the crystallization process of Zn0.5Ni0.5Fe2O4 was studied using DSC technique, and kinetic parameters were determined by Kissinger equation and Moynihan et al. equation. The value of the activation energy associated with the crystallization process of Zr0.5Ni0.5Fe2O4 is 220.89 kJ-mol-1. The average value of the Avrami exponent, n, is equal to 1.59±0.13, which suggests that crystallization process of Zn0.5Ni0.5Fe2O4 is the random nucleation and growth of nuclei reaction. 展开更多
关键词 magnetic material Zn0.5Ni0.5Fe2O4 non-isothermal kinetics crystallization process solid-state reaction at low heat
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Effect of Al_2O_3 addition on the non-isothermal crystallization kinetics and long-term stability of BCABS sealing glass for IT-SOFCs 被引量:4
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作者 Zuzhi HUANG Linghong LUO +4 位作者 Liangguang LIU Leying WANG Liang CHENG Xu XU Yefan WU 《Journal of Advanced Ceramics》 SCIE CSCD 2018年第4期380-387,共8页
Owing to adjustable thermal expansion performance, BaO–CaO–Al_2O_3–B_2O_3–SiO_2(BCABS) glass has a promising commercialization prospect for intermediate temperature-solid oxide fuel cells(IT-SOFCs) sealing. Herein... Owing to adjustable thermal expansion performance, BaO–CaO–Al_2O_3–B_2O_3–SiO_2(BCABS) glass has a promising commercialization prospect for intermediate temperature-solid oxide fuel cells(IT-SOFCs) sealing. Herein, Al_2O_3 with two different contents was added into the same glass formulation, referred to as A and B glass, respectively. In terms of the non-isothermal crystallization kinetic behavior, the effect of Al_2O_3 as the unique intermediate was innovatively studied on the long-term performance of BCABS sealing glass. After the heat treatment at 1023 K for 100 h, the change of the network structure and the expansion coefficient of the glass were characterized. The results showed that the addition of Al_2O_3 as a network forming body could enhance the structure of glass, and increase the activation energy for glass transition, which could effectively inhibit the crystallization ability of sealing glass. Therefore, the B glass with the higher Al_2O_3 content showed the better long-term sealing ability, which was greatly beneficial for IT-SOFCs sealing. 展开更多
关键词 INTERMEDIATE temperature-solid oxide fuel cell (IT-SOFC) BaO-CaO-Al2O3-B2O3-SiO2 (BCABS)sealing glass Al2O3 non-isothermal crystallization kinetics long-term stability
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Crystal structures and thermal decomposition kinetics of lanthanide complexes with 3,4,5-trimethoxybenzoic acid and 1,10-phenanthroline 被引量:6
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作者 TANG Kun ZHANG JianJun +3 位作者 REN Ning ZHENG JunRu LIU JingYu WU KeZhong 《Science China Chemistry》 SCIE EI CAS 2012年第7期1283-1293,共11页
A series of lanthanide complexes with the 3,4,5-trimethoxybenzoic acid (3,4,5-tmoba) and 1,10-phenanthroline(phen), [Ln(3,4,5-tmoba)3phen]2(Ln = Pr(l), Nd (2) and Ho(3)), have been synthesized and charac... A series of lanthanide complexes with the 3,4,5-trimethoxybenzoic acid (3,4,5-tmoba) and 1,10-phenanthroline(phen), [Ln(3,4,5-tmoba)3phen]2(Ln = Pr(l), Nd (2) and Ho(3)), have been synthesized and characterized by a series of techniques including elemental analysis, IR spectra, X-ray crystallography and TG/DSC-FTIR technology. The three complexes have two kinds of coordination modes, in which the Pr3+ and Nd3+ cations are nine-coordinated and the Ho3+ cation is eight-coordinated. The three-dimensional IR accumulation spectra of gaseous products for complexes 1-3 were analyzed and the gaseous products were identified by the typical IR spectra obtained from the 3D surface graphs. Meanwhile, we obtained the activation energy E of the first steps of complexes 1-3 by the integral isoconversional non-linear (NL-INT) method and discussed the non-isothermal kinetics of complexes 1-3 using the Malek method. Finally, SB(m, n) was defined as the kinetic method of the first-step thermal decomposition. The thermodynamic parameters △G≠, △H≠ and △S≠ of activation at the peak temperature were also calculated. 展开更多
关键词 3 4 5-trimethoxybenzoic acid lanthanide complexes crystal structures non-isothermal kinetics thermodynamic parameters
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高黏PET切片分子质量及其分布对结晶性能的影响
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作者 孙娜 邵义伟 +2 位作者 王丽丽 张玥 张玉梅 《合成纤维》 CAS 2024年第7期7-13,共7页
高黏聚对苯二甲酸乙二醇酯(PET)切片品质对工业丝的纺丝稳定性有很大影响,进而影响PET工业丝的最终性能。采用气相色谱仪、凝胶渗透色谱仪、差示扫描量热仪等对固相缩聚PET切片的特性黏度、端羧基含量、低聚物质量分数,以及分子质量及... 高黏聚对苯二甲酸乙二醇酯(PET)切片品质对工业丝的纺丝稳定性有很大影响,进而影响PET工业丝的最终性能。采用气相色谱仪、凝胶渗透色谱仪、差示扫描量热仪等对固相缩聚PET切片的特性黏度、端羧基含量、低聚物质量分数,以及分子质量及其分布等基本物性参数进行表征,系统研究分子质量及其分布对PET熔融和结晶行为的影响,结果表明:当固相增黏得到的高黏PET切片的分子质量较大、分子质量分布越均匀时,其热性能和结晶性能越稳定,结晶速率越适宜,越有利于进行高温熔融纺丝和高倍拉伸。 展开更多
关键词 高黏聚酯切片 分子质量及其分布 热性能 结晶动力学 结晶性能
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PET/iPBS复合材料的非等温结晶动力学
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作者 刘伟奇 陈绪煌 《塑料》 CAS CSCD 北大核心 2024年第4期8-14,共7页
采用差示扫描量热法研究了聚对苯二甲酸乙二醇酯(PET)及其复合材料的非等温结晶动力学。采用Jeziorny、Mo模型对其进行了描述。结果表明,Jeziorny法能较好地描述复合材料的非等温结晶过程,Mo法能得到最佳的线性关系。Mo法中的α值大致相... 采用差示扫描量热法研究了聚对苯二甲酸乙二醇酯(PET)及其复合材料的非等温结晶动力学。采用Jeziorny、Mo模型对其进行了描述。结果表明,Jeziorny法能较好地描述复合材料的非等温结晶过程,Mo法能得到最佳的线性关系。Mo法中的α值大致相同,这表明,在不同相对结晶度下形成的结晶结构相似。同时,Mo法的另一个参数F(T)随着相对结晶度的增大而增大,这表明,相对结晶度越大,复合材料结晶越困难。利用Friedman方程计算了所有复合材料非等温结晶过程的有效活化能,Dobreva和Gutzow方法计算了成核活性,结果表明,复合材料的活化能和成核活性均小于纯PET,进一步证明了上述结果。 展开更多
关键词 聚对苯二甲酸乙二醇酯 离聚物 非等温结晶动力学 结晶速率 结晶活化能
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