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
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
In this work is described the synthesis of a multifunctional thiolated squalene. Thiol-ene coupling reactions were employed to functionalize the six double bonds of squalene, using thiolacetic acid. Hydrolysis of the ...In this work is described the synthesis of a multifunctional thiolated squalene. Thiol-ene coupling reactions were employed to functionalize the six double bonds of squalene, using thiolacetic acid. Hydrolysis of the resulting thioacetates, rendered the corresponding hexathiolated squalene SQ6SH. This compound was further photopolymerized separately with triallyl cyanurate, pentaerythritol triacrylate and diethyleneglycol divinyl ether. Real Time FTIR kinetics revealed that homopolymerization of the ene monomers took place in addition to the thiol-ene photopolymerization. Flexible films were obtained when SQ6SH was photopolymerized in bulk with the above mentioned unsaturated monomers.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
We synthesized tetrafunctional allyl ether monomer (4-AE) and investigated the effects of the different molar ratios of trimethylolpropane tris-(3-mercaptopropionate) (3-SH) to 4-AE on the photopolymerization behavior...We synthesized tetrafunctional allyl ether monomer (4-AE) and investigated the effects of the different molar ratios of trimethylolpropane tris-(3-mercaptopropionate) (3-SH) to 4-AE on the photopolymerization behavior, morphology, and electro-optical properties of thiol-ene-based PDLC films. Photo-DSC and DSC analyses revealed that the PDLC sample containing 45 wt% 3-SH and 45 wt% 4-AE gave the highest exotherm, the fastest photocure rate, and the highest Tg due to the matched stoichiometry. Morphological observations and electro-optical measurements showed that the PDLC sample with the matched molar ratio gave the smallest LC droplet size, the highest threshold, driving voltages, and lowest saturation transmittance because the orientation of LC molecules got difficulty in small droplets. The stoichiometric ratios of 3-SH to 4-AE played an important role in controlling the photocure rate, phase separation rate, microstructures of LC droplets, and electro-optical properties of thiol-ene-based PDLC systems.展开更多
目的探讨靶向穿刺技术在经皮椎体成形术(PVP)治疗骨质疏松性胸腰椎压缩骨折中的作用,分析其对手术效果及伤椎内骨水泥分布的影响。方法回顾性分析2020年1月—2022年3月北京市顺义区医院骨一科应用PVP治疗骨质疏松性胸腰椎压缩骨折患者11...目的探讨靶向穿刺技术在经皮椎体成形术(PVP)治疗骨质疏松性胸腰椎压缩骨折中的作用,分析其对手术效果及伤椎内骨水泥分布的影响。方法回顾性分析2020年1月—2022年3月北京市顺义区医院骨一科应用PVP治疗骨质疏松性胸腰椎压缩骨折患者113例,男性39例,女性74例;年龄63~75岁,平均68.1岁;高处坠落伤11例,道路交通伤39例,摔伤63例。根据穿刺路径不同分为靶向穿刺组(58例)与常规穿刺组(55例)。比较两组患者手术时间、骨水泥用量、骨水泥渗漏、伤椎内骨水泥分布、术前及术后1 d、3个月VAS及伤椎后凸角(Cobb角)。结果两组术后1 d VAS较术前均有降低[(2.6±0.3)分vs.(8.9±0.5)分、(2.8±0.4)分vs.(8.7±0.6)分,P<0.05],但组间比较差异无统计学意义(P>0.05);术后3个月靶向穿刺组VAS低于常规穿刺组[(0.9±0.2)分vs.(2.4±0.3)分,P<0.05]。两组患者手术时间、骨水泥用量、骨水泥渗漏方面比较差异无统计学意义(P>0.05),但在伤椎骨水泥分布方面靶向穿刺组优于常规穿刺组,差异有统计学意义(P<0.05)。术前及术后1 d伤椎后凸角比较差异无统计学意义(P>0.05),但术后3个月靶向穿刺组的伤椎后凸角小于常规穿刺组[(15.1±1.6)°vs.(21.2±2.0)°,P<0.05]。结论在PVP治疗骨质疏松性胸腰椎压缩骨折中,应用靶向穿刺技术有助于改善伤椎骨水泥分布,在维持椎体高度及改善疼痛方面具有优势,值得临床推广。展开更多
In this study,we investigate the effect of the exposure dose on the mechanical property of the photoresins generated with acrylate self-polymerization and thiol-ene polymerization.The results indicate that the mechani...In this study,we investigate the effect of the exposure dose on the mechanical property of the photoresins generated with acrylate self-polymerization and thiol-ene polymerization.The results indicate that the mechanical performance of the thiol-ene photoresin is highly depended on the exposure dose during the solidification process.With 350-fold exposure dose change,the stiffness of the thiol-ene photoresin reached more that 700-fold change compare to 14-fold of the acrylate photoresin.We developed a TPL photoresist based on our results and show the capability to fabricate microstrucutres with high resolution and variable mechanical performances using this method.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.
文摘In this work is described the synthesis of a multifunctional thiolated squalene. Thiol-ene coupling reactions were employed to functionalize the six double bonds of squalene, using thiolacetic acid. Hydrolysis of the resulting thioacetates, rendered the corresponding hexathiolated squalene SQ6SH. This compound was further photopolymerized separately with triallyl cyanurate, pentaerythritol triacrylate and diethyleneglycol divinyl ether. Real Time FTIR kinetics revealed that homopolymerization of the ene monomers took place in addition to the thiol-ene photopolymerization. Flexible films were obtained when SQ6SH was photopolymerized in bulk with the above mentioned unsaturated monomers.
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.
文摘We synthesized tetrafunctional allyl ether monomer (4-AE) and investigated the effects of the different molar ratios of trimethylolpropane tris-(3-mercaptopropionate) (3-SH) to 4-AE on the photopolymerization behavior, morphology, and electro-optical properties of thiol-ene-based PDLC films. Photo-DSC and DSC analyses revealed that the PDLC sample containing 45 wt% 3-SH and 45 wt% 4-AE gave the highest exotherm, the fastest photocure rate, and the highest Tg due to the matched stoichiometry. Morphological observations and electro-optical measurements showed that the PDLC sample with the matched molar ratio gave the smallest LC droplet size, the highest threshold, driving voltages, and lowest saturation transmittance because the orientation of LC molecules got difficulty in small droplets. The stoichiometric ratios of 3-SH to 4-AE played an important role in controlling the photocure rate, phase separation rate, microstructures of LC droplets, and electro-optical properties of thiol-ene-based PDLC systems.
文摘目的探讨靶向穿刺技术在经皮椎体成形术(PVP)治疗骨质疏松性胸腰椎压缩骨折中的作用,分析其对手术效果及伤椎内骨水泥分布的影响。方法回顾性分析2020年1月—2022年3月北京市顺义区医院骨一科应用PVP治疗骨质疏松性胸腰椎压缩骨折患者113例,男性39例,女性74例;年龄63~75岁,平均68.1岁;高处坠落伤11例,道路交通伤39例,摔伤63例。根据穿刺路径不同分为靶向穿刺组(58例)与常规穿刺组(55例)。比较两组患者手术时间、骨水泥用量、骨水泥渗漏、伤椎内骨水泥分布、术前及术后1 d、3个月VAS及伤椎后凸角(Cobb角)。结果两组术后1 d VAS较术前均有降低[(2.6±0.3)分vs.(8.9±0.5)分、(2.8±0.4)分vs.(8.7±0.6)分,P<0.05],但组间比较差异无统计学意义(P>0.05);术后3个月靶向穿刺组VAS低于常规穿刺组[(0.9±0.2)分vs.(2.4±0.3)分,P<0.05]。两组患者手术时间、骨水泥用量、骨水泥渗漏方面比较差异无统计学意义(P>0.05),但在伤椎骨水泥分布方面靶向穿刺组优于常规穿刺组,差异有统计学意义(P<0.05)。术前及术后1 d伤椎后凸角比较差异无统计学意义(P>0.05),但术后3个月靶向穿刺组的伤椎后凸角小于常规穿刺组[(15.1±1.6)°vs.(21.2±2.0)°,P<0.05]。结论在PVP治疗骨质疏松性胸腰椎压缩骨折中,应用靶向穿刺技术有助于改善伤椎骨水泥分布,在维持椎体高度及改善疼痛方面具有优势,值得临床推广。
基金the National Natural Science Foundation of China(Nos.22002015 and 52033002)the Fundamental Research Funding from Jiangsu Province(No.BK20211560)the Fundamental Research Funds for the Central Universities(No.2242018R20011).
文摘In this study,we investigate the effect of the exposure dose on the mechanical property of the photoresins generated with acrylate self-polymerization and thiol-ene polymerization.The results indicate that the mechanical performance of the thiol-ene photoresin is highly depended on the exposure dose during the solidification process.With 350-fold exposure dose change,the stiffness of the thiol-ene photoresin reached more that 700-fold change compare to 14-fold of the acrylate photoresin.We developed a TPL photoresist based on our results and show the capability to fabricate microstrucutres with high resolution and variable mechanical performances using this method.
