脂肪族超支化聚酯的端链结晶行为  

End-Chain Crystallization Behavior of Aliphatic Hyperbranched Polyesters

作　　者：刘晶如[1] 巢玲玲[1] 丁镜[1] 俞强[1] 

机构地区：[1]常州大学材料科学与工程学院,江苏常州213164

出　　处：《高校化学工程学报》2014年第6期1353-1359,共7页Journal of Chemical Engineering of Chinese Universities

基　　金：江苏省大学生科技创新基金(SCZ1117400050)

摘　　要：以长链烷基酸为改性剂,对以三羟甲基丙烷为核、二羟甲基丙酸为支化单体合成的第三代端羟基超支化聚酯进行端基改性,采用羟值滴定和核磁共振氢谱(1H-NMR)表征超支化聚酯的改性程度,采用差示扫描量热分析(DSC)和广角X射线衍射(WAXD)研究了端烷烃链长度和端基改性程度对超支化聚酯相转变行为和结晶行为的影响。结果表明,超支化聚酯的结晶归因于长链端烷烃的有序排列,端烷烃链越长,端烷基超支化聚酯的冷结晶温度、热结晶温度和熔融温度均逐渐升高;端烷烃链越长或改性程度越高,衍射峰强度越大,晶粒尺寸变小。进一步用DSC研究了端十八烷基超支化聚酯的非等温结晶行为并用Ozawa法对其非等温结晶动力学进行了分析,发现其成核方式为异相成核,生长方式为针状晶体的一维生长。The third generation of hydroxyl-terminated hyperbranched polyester based on 1,1,1-trimethylolpropane as core and 2,2-bis （hydroxymethyl） propionic acid as AB2-monomer was end-capped with long-chain n-alkyl carboxylic acids. The degree of modification of hyperbranched polyesters was confirmed by titration of hydroxyl values and proton nuclear magnetic resonance （1H-NMR）. The influences of end-chain length and degree of modification on phase transition behavior and crystallization behavior of hyperbranched polyesters were investigated by differential scanning calorimeter （DSC） and wide angle X-ray diffraction （WAXD）. The results show that the crystallization of hyperbranched polyesters can be attributed to the ordered arrangement of long-chain end alkanes. The values of cooling crystallization temperature and melt crystallization temperature and melting temperature increase with increasing length of the alkyl chains. With a sufficiently long alkyl chain or the increase of degree of modification, the polymers tend to crystallize, the diffraction intensity gets strengthened and the size of crystals decreased. The non-isothermal crystallization behavior of octadecyl-terminated hyperbranched polyester was performed by DSC at various cooling rates and the kinetic study was further analyzed by using Ozawa method. The nucleation method of HBP-C18 is heterogeneous nucleation, and the growth way is one-dimensional acicular crystal growth.

关 键 词：超支化聚酯 端烷基 结晶 相转变 

分 类 号：TQ323.4[化学工程—合成树脂塑料工业]