Biobased aromatic-aliphatic polyols were previously synthesized from a thermal thiol-ene reaction of propoxylated cardanol with 2-mercaptoethanol(ME)in the presence of azobisisobutyronitrile(AIBN)as a radical initiato...Biobased aromatic-aliphatic polyols were previously synthesized from a thermal thiol-ene reaction of propoxylated cardanol with 2-mercaptoethanol(ME)in the presence of azobisisobutyronitrile(AIBN)as a radical initiator.Cardanol used for this purpose was obtained as a dark-brown liquid(Gardner Color Reference^18).The photochemical thiol-ene reaction can also be used to prepare aromatic-aliphatic polyols by employing cardanol.Via the photochemical thiol-ene reaction,2-mercaptoethanol was added successfully to C=C double bond of cardanol,suggesting that phenolic group may not play an inhibitory role in the radical thiol-ene reaction.However,we preferred to alkoxylate the phenolic hydroxyl group of cardanol,which is much more reactive with isocyanates than phenolic hydroxyls,to generate a new aliphatic hydroxyl group.Furthermore,the functionality of polyols was also improved by two methods:1)using 1-thio-glycerol instead of 2-mercaptoethanol and 2)using alkoxylated cardanol with glycidol(Cardanol-GLY)instead of propoxylated cardanol(Cardanol-PO).These polyols were then used in preparation of rigid polyurethane foams that can be useful in various applications such as insulation of freezers,pipes and storage tanks in food and chemical industries.展开更多
Aromatic-aliphatic polyols were obtained previously from the thiol-ene reactions of propoxylated cardanol with hydroxyalkyl mercaptans;these aromatic-aliphatic polyols were then utilized in the preparation of rigid po...Aromatic-aliphatic polyols were obtained previously from the thiol-ene reactions of propoxylated cardanol with hydroxyalkyl mercaptans;these aromatic-aliphatic polyols were then utilized in the preparation of rigid polyurethane foams with excellent properties.The current work describes a variant of cardanol polyol synthesis by thiol-ene reactions in three steps.The first step is propoxylation of cardanol by reacting cardanol with propylene oxide;the second step is mercaptanization of propoxylated cardanol by reacting double bonds with hydrogen sulfide;and the third step involves the addition of the thiol groups of mercaptanized propoxylated cardanol to the double bonds of allyl alcohol,glycerol-1-allyl ether,and trimethylolpropane allyl ether.Thus,obtained polyols were characterized by standard analytical methods.Rigid polyurethane foams prepared from these polyols show promising physical-mechanical properties.The rigid polyurethane foams can be used for various applications such as thermo-insulation of freezers,storage tanks and pipes for food and chemical industries,wood substitutes and flotation materials.展开更多
The GH3535 alloy samples were irradiated using 15-MeV Te^(4+) ions at 650℃to a dose of 0.5,3.0,10,and 20 dpa,respectively.The Te atoms distribution and microstructure evolution were examined by electron probe microan...The GH3535 alloy samples were irradiated using 15-MeV Te^(4+) ions at 650℃to a dose of 0.5,3.0,10,and 20 dpa,respectively.The Te atoms distribution and microstructure evolution were examined by electron probe microanalysis(EPMA)and transmission electron microscopy(TEM).The nano-indenter was then used to measure the nano-hardness changes of samples before and after irradiation.TEM results showed the formation of dislocation loops in the irradiated samples.Their mean diameters increase with the increase of irradiation dose and tends to be saturated when irradiation dose exceeds 10 dpa.The ratio of yield strength increments calculated by dispersed barrier hardening(DBH)model is basically consistent with that of nano-hardness increments measured by nano-indenter.In addition,the relationship between the nano-hardness increments and dpa for the GH3535 alloy irradiated by Te ions has been revealed in the study.展开更多
Cardanol is a natural phenol which is obtained from high vacuum distillation of cashew nut shell liquid.It contains a hydrocarbon chain of 15 carbon atoms in the meta position,either with one,two or three nonconjugate...Cardanol is a natural phenol which is obtained from high vacuum distillation of cashew nut shell liquid.It contains a hydrocarbon chain of 15 carbon atoms in the meta position,either with one,two or three nonconjugated double bonds.This article describes thermal thiol-ene reaction to synthesize new cardanol-based polyols for polyurethanes with aromatic-aliphatic structure.Phenolic hydroxyl group was blocked by alkoxylation and 2-mercaptoethanol was added to the double bonds of propoxylated cardanol.The resultant product is a mixture of polyols that may contain one,two,three or four hydroxyl groups,as a function of the number of double bonds reacted with 2-mercaptoethanol.Similar polyols,but with much higher functionality,were also synthesized from condensation of cardanol-based novolacs with formaldehyde.These cardanolbased polyols were further utilized to prepare rigid polyurethane foams(PUs)with excellent physical and mechanical properties,useful for various applications in chemical and food industries.展开更多
文摘Biobased aromatic-aliphatic polyols were previously synthesized from a thermal thiol-ene reaction of propoxylated cardanol with 2-mercaptoethanol(ME)in the presence of azobisisobutyronitrile(AIBN)as a radical initiator.Cardanol used for this purpose was obtained as a dark-brown liquid(Gardner Color Reference^18).The photochemical thiol-ene reaction can also be used to prepare aromatic-aliphatic polyols by employing cardanol.Via the photochemical thiol-ene reaction,2-mercaptoethanol was added successfully to C=C double bond of cardanol,suggesting that phenolic group may not play an inhibitory role in the radical thiol-ene reaction.However,we preferred to alkoxylate the phenolic hydroxyl group of cardanol,which is much more reactive with isocyanates than phenolic hydroxyls,to generate a new aliphatic hydroxyl group.Furthermore,the functionality of polyols was also improved by two methods:1)using 1-thio-glycerol instead of 2-mercaptoethanol and 2)using alkoxylated cardanol with glycidol(Cardanol-GLY)instead of propoxylated cardanol(Cardanol-PO).These polyols were then used in preparation of rigid polyurethane foams that can be useful in various applications such as insulation of freezers,pipes and storage tanks in food and chemical industries.
文摘Aromatic-aliphatic polyols were obtained previously from the thiol-ene reactions of propoxylated cardanol with hydroxyalkyl mercaptans;these aromatic-aliphatic polyols were then utilized in the preparation of rigid polyurethane foams with excellent properties.The current work describes a variant of cardanol polyol synthesis by thiol-ene reactions in three steps.The first step is propoxylation of cardanol by reacting cardanol with propylene oxide;the second step is mercaptanization of propoxylated cardanol by reacting double bonds with hydrogen sulfide;and the third step involves the addition of the thiol groups of mercaptanized propoxylated cardanol to the double bonds of allyl alcohol,glycerol-1-allyl ether,and trimethylolpropane allyl ether.Thus,obtained polyols were characterized by standard analytical methods.Rigid polyurethane foams prepared from these polyols show promising physical-mechanical properties.The rigid polyurethane foams can be used for various applications such as thermo-insulation of freezers,storage tanks and pipes for food and chemical industries,wood substitutes and flotation materials.
基金the National Natural Science Foundation of China(Grant Nos.11975304 and 12022515).
文摘The GH3535 alloy samples were irradiated using 15-MeV Te^(4+) ions at 650℃to a dose of 0.5,3.0,10,and 20 dpa,respectively.The Te atoms distribution and microstructure evolution were examined by electron probe microanalysis(EPMA)and transmission electron microscopy(TEM).The nano-indenter was then used to measure the nano-hardness changes of samples before and after irradiation.TEM results showed the formation of dislocation loops in the irradiated samples.Their mean diameters increase with the increase of irradiation dose and tends to be saturated when irradiation dose exceeds 10 dpa.The ratio of yield strength increments calculated by dispersed barrier hardening(DBH)model is basically consistent with that of nano-hardness increments measured by nano-indenter.In addition,the relationship between the nano-hardness increments and dpa for the GH3535 alloy irradiated by Te ions has been revealed in the study.
文摘Cardanol is a natural phenol which is obtained from high vacuum distillation of cashew nut shell liquid.It contains a hydrocarbon chain of 15 carbon atoms in the meta position,either with one,two or three nonconjugated double bonds.This article describes thermal thiol-ene reaction to synthesize new cardanol-based polyols for polyurethanes with aromatic-aliphatic structure.Phenolic hydroxyl group was blocked by alkoxylation and 2-mercaptoethanol was added to the double bonds of propoxylated cardanol.The resultant product is a mixture of polyols that may contain one,two,three or four hydroxyl groups,as a function of the number of double bonds reacted with 2-mercaptoethanol.Similar polyols,but with much higher functionality,were also synthesized from condensation of cardanol-based novolacs with formaldehyde.These cardanolbased polyols were further utilized to prepare rigid polyurethane foams(PUs)with excellent physical and mechanical properties,useful for various applications in chemical and food industries.
