• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Applied Polymer Science >Blends of aliphatic polyesters .2. Hydrolysis of solution-cast blends from poly(L-lactide) and poly(epsilon-caprolactone) in phosphate-buffered solution
【24h】

Blends of aliphatic polyesters .2. Hydrolysis of solution-cast blends from poly(L-lactide) and poly(epsilon-caprolactone) in phosphate-buffered solution

机译：脂族聚酯的混合物.2。聚（L-丙交酯）和聚（ε-己内酯）在磷酸盐缓冲液中的溶液浇铸共混物的水解

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Blend films were prepared from poly(L-lactide) (PLLA) and poly(epsilon-caprolactone) (PCL) with different PLLA contents [X-PLLA (w/w) = PLLA/(PCL + PLLA)] by the solution-casting method and their hydrolysis behaviors were investigated up to 20 months in a phosphate-buffered solution of pH 7.4 at 37 degrees C by gel permeation chromatography, tensile testing, differential scanning calorimetry, and gravimetry. Polarizing microscopic observation and dynamic mechanical analysis revealed that PCL and PLLA were phase-separated in blend films before hydrolysis. The mass remaining, molecular weight, and tensile strength of the blend films with X-PLLA Of 0.5 and 0.75 decreased more rapidly by hydrolysis than those of the nonblended PLLA, while the elongation at break of the blend film of X-PLLA = 0.25 decreased the slowest. The rate constant for hydrolysis (k) calculated from the M-n change during hydrolysis was higher for blend films of X-PLLA = 0.5 and 0.75 than those expected from k of nonblended PLLA and PCL. The melting temperature (T-m) of PLLA in the blend and nonblended films of X-PLLA = 0.5, 0.75, and 1 decreased from 179 to 161, 160, and 175 degrees C upon hydrolysis for 20 months, respectively, while that for X-PLLA = 0.25 slightly increased from 176 to 177 degrees C. On the other hand, T-m and the crystallinity of PCL was significantly increased by hydrolysis for 20 months, irrespective of X-PLLA. (C) 1998 John Wiley & Sons, Inc. [References: 30]
机译：由具有不同PLLA含量[X-PLLA（w / w）= PLLA /（PCL + PLLA）]的聚（L-丙交酯）（PLLA）和聚（ε-己内酯）（PCL）制备共混膜，方法是：通过凝胶渗透色谱法，拉伸试验，差示扫描量热法和重量分析法，在37℃，pH 7.4的磷酸盐缓冲溶液中研究了20个月的流延法及其水解行为。偏光显微镜观察和动态力学分析表明，水解前共混膜中PCL和PLLA相分离。 X-PLLA = 0.5和0.75的X-PLLA共混膜的残留质量，分子量和拉伸强度比未共混的PLLA水解更快，而X-PLLA = 0.25的共混膜的断裂伸长率降低最慢的。对于X-PLLA = 0.5和0.75的共混膜，由水解过程中M-n变化计算的水解速率常数（k）高于非共混PLLA和PCL的k预期的常数。 X-PLLA的共混膜和非共混膜中PLLA的熔融温度（Tm）分别为0.5、0.75和0.75，水解20个月后分别从179降低到161、160和175摄氏度，而X- PLLA = 0.25从176摄氏度略微提高到177摄氏度。另一方面，不管X-PLLA如何，水解20个月，Tm和PCL的结晶度都会显着提高。 （C）1998 John Wiley＆Sons，Inc. [参考：30]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号