Huang Wenyan, Gu Weikai, Yang Hongjun, Xue Xiaoqiang, Jiang Bibiao, Zhang Dongliang, Fang Jianbo, Chen Jianhai, Yang Yang, Guo Jinlong
School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China.
Polymers (Basel). 2017 Jan 6;9(1):14. doi: 10.3390/polym9010014.
Radical solvent-free suspension polymerization of styrene with 3-mercapto hexyl-methacrylate (MHM) as the branching monomer has been carried out using 2,2'-azobisisobutyronitrile (AIBN) as the initiator to prepare branched polymer beads of high purity. The molecular weight and branching structure of the polymers have been characterized by triple detection size exclusion chromatography (TD-SEC), proton nuclear magnetic resonance spectroscopy (¹H-NMR), and Fourier transform infrared spectroscopy (FTIR). The glass transition temperature and rheological properties have been measured by using differential scanning calorimetry (DSC) and rotational rheometry. At mole ratios of MHM to AIBN less than 1.0, gelation was successfully avoided and branched polystyrene beads were prepared in the absence of any solvent. Branched polystyrene has a relatively higher molecular weight and narrower polydispersity ( = 1,036,000 g·mol, / = 7.76) than those obtained in solution polymerization. Compared with their linear analogues, lower glass transition temperature and decreased chain entanglement were observed in the presently obtained branched polystyrene because of the effects of branching.
以2,2'-偶氮二异丁腈(AIBN)为引发剂,以3-巯基己基甲基丙烯酸酯(MHM)为支化单体,进行了苯乙烯的无溶剂自由基悬浮聚合,以制备高纯度的支化聚合物珠粒。通过三检测尺寸排阻色谱法(TD-SEC)、质子核磁共振光谱法(¹H-NMR)和傅里叶变换红外光谱法(FTIR)对聚合物的分子量和支化结构进行了表征。使用差示扫描量热法(DSC)和旋转流变仪测量了玻璃化转变温度和流变性能。在MHM与AIBN的摩尔比小于1.0时,成功避免了凝胶化,并且在没有任何溶剂的情况下制备了支化聚苯乙烯珠粒。与溶液聚合得到的产物相比,支化聚苯乙烯具有相对较高的分子量和较窄的多分散性( = 1,036,000 g·mol, / = 7.76)。由于支化的影响,与它们的线性类似物相比,目前得到的支化聚苯乙烯具有较低的玻璃化转变温度和减少的链缠结。