摘要
以戊二胺为原料分别与癸二酸、十二碳二元酸、十三碳二元酸通过成盐、熔融缩聚两步法合成制备了3种新型生物基长碳链尼龙510、尼龙512和尼龙513(PA5X)。凝胶渗透色谱不可逆反应动力学分析表明,随反应时间延长,产物的相对分子质量逐渐增大,分子量分布逐渐降低,PA5X10,PA512及PA513均符合三级动力学反应,聚合速率常数分别为19.79,25.80和23.19;红外光谱与核磁共振分析表明,经熔融缩聚后所有的小分子PA5X盐已聚合为高分子的PA5X,无其它结构产物生成;差示扫描量热法与热重分析表明,随重复单元链长增加,PA5X的熔点逐渐降低,分别为214℃,209℃和204℃,分解温度均在400℃以上;力学性能测试结果表明,PA5X的拉伸强度在54~60 MPa之间,断裂伸长率均达到200%以上,随二元酸链长的增加,PA5X的弯曲强度和冲击性能有一定下降。
The synthesis of three bio-based long-chain polyamides,namely Nylon 510,Nylon 512,and Nylon 513(PA5X),was accomplished through a two-step process involving the salt formation and melt polycondensation reactions of hexamethylenediamine with sebacic acid,dodecanedioic acid,and tridecanedioic acid,respectively.Gel permeation chromatography(GPC)analyses of the irreversible reaction kinetics indicate an increase in the relative molecular weight of the products with prolonged reaction time,accompanied by a gradual reduction in molecular weight distribution.PA5X10,PA512,and PA513 exhibit third-order kinetics,with polymerization rate constants of 19.79,25.80,and 23.19,respectively.Fourier-transform infrared spectroscopy(FT-IR)and nuclear magnetic resonance(NMR)analyses reveal that all small-molecule PA5X salts undergo polymerization into high molecular-weight PA5X after melt polycondensation,with no other structural byproducts formed.Differential scanning calorimetry(DSC)and thermogravimetric(TG)analyses demonstrate that the melting points of PA5X decrease gradually with an increase in the length of repeating unit chain,reaching 214℃,209℃,and 204℃,respectively,while the decomposition temperatures are all above 400℃.Mechanical property results indicate that the tensile strength of PA5X ranges from 54 MPa to 60 MPa,with fracture elongation exceeding 200%.The bending strength and impact resistance exhibit a slight decrease with an increase in the chain length of dicarboxylic acid.
作者
周阳
潘凯
Yang Zhou;Kai Pan(College of Materials Science and Engineering,Beijing University of Chemical Technology,Beijing 100029,China)
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2024年第2期9-19,共11页
Polymer Materials Science & Engineering
关键词
生物基材料
长碳链尼龙
反应动力学
力学性能
bio-based materials
long carbon chain nylon
reaction kinetics
mechanical properties
