摘要
采用溶液法制备聚乳酸(PLA)薄膜,并利用偏光显微镜在线研究了不同温度及不同牵引速率下,单根蚕丝纤维(SF)诱导PLA柱晶的形成,并利用显微红外光谱表征柱晶结构.结果表明,当牵引速率大于或等于临界速率时,纤维表面有连续的柱晶生成,反之柱晶不连续;当牵引速率大于临界饱和速率时,柱晶的结晶度和取向度分别趋于稳定值;在等温条件下,随着牵引速率的增大,柱晶的成核诱导期缩短,晶体的成核密度增大,取向度增加;当牵引速率一定时,与130℃相比,温度为120℃时形成柱晶的成核诱导期较短,成核密度更大,结晶度更高,柱晶层的生长更快.
Thin films of poly( lactic acid)( PLA) were prepared using solution method. At different temperatures and fiber-pulling speeds,the morphology of cylindrites induced by a single silkworm silk fiber( SF) in PLA films was investigated by polarized optical microscopy( POM) and Fourier transform infrared spectroscopy( FTIR). The results show that there is a critical fiber-pulling speed,above which the continuous cylindrites structure could be generated on the fiber surface,whereas discontinuous cylindrites would form at a speed lower than that value. Besides,there also exists another special speed defined as saturation fiber-pulling speed,and once the pulling rate exceeds that value,the degree of crystallization and orientation will reach a plateau. Moreover,at the same temperature,the induction period of cylindrites nuclei reduces and its nuclei density and the orientation increase with raising the fiber-pulling speed; under a given fiber-pulling speed,compared to 130 ℃,the induction period of cylindrites is shorter,and its nuclei density,growth rate as well as final crystallinity are much higher at 120 ℃.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2017年第9期1663-1669,共7页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:51573171
21503194)
郑州大学优秀青年教师发展基金(批准号:1521502001)资助~~
关键词
聚乳酸
蚕丝纤维
柱晶
牵引速率
Poly(lactic acid)
Silkworm silk fiber
Cylindrite
Fiber-pulling speed