非异氰酸酯法合成酰胺型可生物降解聚氨酯热塑弹性体及其性能研究

Thermoplastic polyurethane elastomers (TPUs) have excellent properties such as high melting point, good mechanical properties and thermoplastic characteristics. They are widely used as films, rubbery fibers, automobile articles, hot melt adhensives and medical products. At present, TPUs are commonly synthesized through isocyanate route. Isocyanates are highly toxic materials and very harmful to human body during TPUs production and their usage. Meanwhile, TPUs synthesized especially from aromatic isocyanates have poor biodegradability in the natural environment. So, it is very important to synthesize biodegradable TPUs through non-isocyanate route. In this research, we utilize our established method to synthesize nylon-6 oligomers (H2N-PA-OH) from acid catalyzed polymerization of caprolactam with aminoethanol, and synthesize polyamide oligomers (HO-carbamate-PA-OH) having carbamate linkages from the reaction of H2N-PrePA-OH with ethylene carbonate. Through melt polycondensation of HO-carbamate-PA-OH with aliphatic polyester or polyether glycol, we synthesize polyurethane prepolymers HO-PrePEAU-OH, and conduct the chain extension with carbonylbiscaprolactamate to obtain high molecular weight thermoplastic poly(amide urethane) elastomers (TPEAUs) which have short Nylon-6 hard segments and aliphatic polyester or polyether soft segments. By thoroughly studying the influencing factors in the polycondensation and chain extension and characterizing their physical properties such Tg, Tm, crystallinity, crystallites, tensile strength, elongation at break, storage modulus (E'),loss modulus (E'') and biodegradability, we obtain the knowledge about the correlation between the structure and the properties of the TPEAUs, and establish the methods to regulate their structure and properties. As biodegradable nylon-6 oligomers having high Tm, high crystallinity and high intermolecular strength are used as hard segments and biodegradable polyester or polyether glycol are selected as soft segments, new kind of biodegradable TPEAUs with high Tm, good crystallinity, high tensile strength and good toughness should be prepared. Through this research, a new non-isocyanate route will be established to synthesize new kind of biodegradable TPUs having good thermal and mechanical properties. Polymer synthetic chemistry in this area will be enriched as well.

聚氨酯热塑弹性体（TPUs）性能好，用途广，但目前以有毒的异氰酸酯合成，对人体危害大；难降解。研究新的合成方法，制备性能优良的可生物降解TPUs，具有重要的理论和实际意义。本申请以己内酰胺与乙醇胺聚合得到的端氨基、端羟基尼龙-6低聚体，与碳酸乙烯酯反应形成带氨基甲酸酯结构的聚酰胺二醇，经与聚酯或聚醚二元醇熔融缩聚并以碳酰双己内酰胺扩链，合成高分子量的聚酯/聚醚-酰胺型聚氨酯热塑弹性体（TPEAUs）。系统地研究影响缩聚和扩链的各种因素，及不同软硬段TPEAUs结构与性能间的关系，获得调控结构与性能的方法。研究中采用易结晶、熔点高、分子间力强且可生物降解的短尼龙-6段为硬段，以可生物降解的聚酯或聚醚等构成软段，可使此TPEAUs具有良好结晶性、强度、柔韧性和生物降解性。由此建立一种非异氰酸酯法制备高分子量可生物降解TPUs的新方法，绿色、环保、高效，丰富和发展聚合物的合成化学。

热塑性聚氨酯（TPUs）具有优良的综合性能，用途广，但目前主要以有毒的异氰酸酯合成，对人体危害大。研究利用非异氰酸酯法制备性能优良的TPUs，具有重要的理论和实际意义。本项目中，首先利用乙二胺、丁二胺和己二胺，合成了三种二氨酯二醇，研究了它们的自缩聚，发现己二氨酯二醇（BHCH）可经自缩聚，获得Mn达29200的聚己二氨酯（PBHCH），其熔点为154.3 ℃，拉伸强度为28.41 MPa，断裂伸长率为3.91 %，强度好但较脆。为了增韧改性，合成了数种同时带有端氨基及端羟基的尼龙-6低聚物（H2N-PrePA-OH），经与己内酯反应转化为端羟基尼龙-6低聚体（HO-PA-OH），再与BHCH共缩聚，获得了Mn在26000以上、熔点在123.9～172.2 ℃之间、拉伸强度达31.50 MPa、断裂伸长率达447.49 %的酰胺型聚氨酯（PAUs）。此外，还利用两种HO-PA-OH与BHCH及不同分子量的聚乙二醇（HO-PEG-OH）共缩聚，合成了分子量在29600以上、熔点在145.8～177.4 ℃之间、拉伸强度达30.03 MPa、断裂伸长率达286.8%的酰胺型聚醚氨酯（s-PEAUs）。由此确立了非异氰酸酯新方法，即利用二氨酯二醇的直接缩聚，合成高分子量、可结晶的热塑性聚二氨酯；通过引入短尼龙-6段及短尼龙-6段、聚醚段，来合成高分子量、可结晶、力学性能优良的热塑性酰胺型聚氨酯及酰胺型聚醚氨酯；并获得了对其结构、性能间关系的清楚认识；此外还在可生物降解聚酯、聚酯酰胺研究方面，取得了新进展。相关研究共申请专利3项，发表论文6篇（SCI 4篇），另有三篇已投稿（一篇在退修中），两篇在整理当中。