• 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 >SUSCEPTIBILITY OF STARCH-FILLED AND STARCH-BASED LDPE TO OXYGEN IN WATER AND AIR
【24h】

SUSCEPTIBILITY OF STARCH-FILLED AND STARCH-BASED LDPE TO OXYGEN IN WATER AND AIR

机译：淀粉和基于淀粉的LDPE对水和空气中氧气的敏感性

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

The susceptibility of starch-filled and starch-based polyethylenes to oxygen in water and air was analyzed and compared. LDPE containing 7.7% starch and a prooxidant formulation in the form of masterbatch (LDPE-MB) was compared to pure LDPE, LDPE with 7.7% starch (LDPE-starch), and a blend with 70% starch, and 30% ethylene maleic anhydride (starch-EMA). Thermal ageing at 80 degrees C in air and water was followed by monitoring the molecular weight changes, the formation of carbonyl groups, and degradation products by SEC, FTIR, and GC-MS. It was demonstrated that LDPE-MB was the most susceptible material to degradation in both environments, although the degradation was faster in air than in water. The slower degradation in water is explained by a deactivation or leaching out of the pro-oxidant during the aging. The degradation of pure LDPE and starch-EMA is faster in water than in air. LDPE-starch was the only material that did not degrade during 11 weeks in water at 80 degrees C. The addition of starch to LDPE made this material even more stable than pure LDPE to aging in water. The molecular weight distribution of LDPE-MB narrowed during aging in air. In water, on the other hand, the MWD of LDPE-MB, LDPE, and LDPE-starch broadened. The lower oxygen concentration in water increases the probability for molecular enlargement reactions in comparison to the case in air. Mono- and dicarboxylic acids were the major products identified in both environments. Ketoacids were formed in both air and water, but ketones and hydrocarbons were only identified after aging in air. Either these products are not formed or they remain in the polymer matrix rather than migrate out into the water. Lactic acid and 2-furancarboxaldehyde were only identified in the starch-EMA material degraded in water at 80 degrees C. LDPE, LDPE-starch, and starch-EMA did not form any degradation products during 11 weeks at 80 degrees C in air in agreement with the neglible molecular weight changes observed. (C) 1997 John Wiley & Sons, Inc. [References: 23]
机译：分析并比较了淀粉填充和淀粉基聚乙烯对水和空气中氧气的敏感性。将含有7.7％淀粉和母料形式的助氧化剂配方（LDPE-MB）的LDPE与纯LDPE，具有7.7％淀粉的LDPE（LDPE-淀粉）以及70％淀粉和30％乙烯马来酸酐的混合物进行比较（淀粉EMA）。随后在80°C的空气和水中进行热老化，然后通过SEC，FTIR和GC-MS监测分子量变化，羰基的形成和降解产物。结果表明，LDPE-MB在两种环境中都是最容易降解的材料，尽管空气中的降解速度比水中的降解速度快。水中降解较慢的原因是在老化过程中钝化剂失活或浸出。纯LDPE和淀粉-EMA的降解在水中比在空气中更快。 LDPE淀粉是唯一在80摄氏度的水中在11周内不会降解的材料。向LDPE中添加淀粉使该材料比纯LDPE在水中的老化更加稳定。 LDPE-MB的分子量分布在空气中老化过程中变窄。另一方面，在水中，LDPE-MB，LDPE和LDPE淀粉的MWD扩大了。与空气中的情况相比，水中较低的氧气浓度增加了分子扩大反应的可能性。一元和二元羧酸是两种环境中鉴定出的主要产品。空气和水中均会生成酮酸，但只有在空气中老化后才能鉴定出酮和碳氢化合物。这些产物要么没有形成，要么保留在聚合物基质中，而不是迁移到水中。仅在80°C的水中降解的淀粉-EMA材料中鉴定出了乳酸和2-呋喃甲醛。一致认为LDPE，LDPE-淀粉和淀粉-EMA在80°C的空气中在11周内未形成任何降解产物随分子量的变化而变化。 （C）1997 John Wiley＆Sons，Inc. [参考：23]

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