Synthesis and Characterization of Novel Copolymers Based on 3 （S）-Methyl-Morpholine-2,5-Dione   总被引：1，自引：1，他引：0  

冯亚凯  陈程斌  张利  田鸿  袁文婕 《天津大学学报(英文版)》2012,18(5):315-319

A series of novel copolymers were successfully synthesized by ring-opening polymerization(ROP) of 3(S)-methyl-morpholine-2,5-dione(MMD) and 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one(MBC) using stannous octoate as catalyst.The copolymers were characterized by means of 1 H-NMR and FT-IR spectroscopy.Gel permeation chromatography(GPC) test shows that the average-number relative molecular mass and average-weight relative molecular mass slightly increase with the increase of MBC content in feed.The results of differential scanning calorimetry(DSC) demonstrate that the glass transition temperature of copolymers increases with the increase of MBC content in copolymers.The copolymers of MMD and MBC are amorphous copolymers,as indicated by DSC results,while the homopolymer of MMD is semicrystalline.  相似文献   

我国女子七项全能重点项目的相关分析   总被引：1，自引：0，他引：1  

袁文婕  袁文君 《南京体育学院学报(社会科学版)》1997,(3)

在女子全能运动的训练中，必须找出对全局起关键作用的项目，重点突破，以此来带动总体的发展。通过搜集国内外优秀运动员的成绩，用统计学方法进行相关分析，得出女子全能运动中对全局起关键作用的项目为200m、铅球、跳高三项的结论。  相似文献