• 主题
高级搜索  >
历史搜索 清空历史
首页> 美国政府科技报告 >Synthesis Characterization and Morphology of a Cis 1,4 Polyisoprene/Poly n-Butylmethacrylate Diblock Copolymer
【24h】

Synthesis Characterization and Morphology of a Cis 1,4 Polyisoprene/Poly n-Butylmethacrylate Diblock Copolymer

机译：顺1,4聚异戊二烯/聚甲基丙烯酸正丁酯二嵌段共聚物的合成表征和形态

获取原文
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Homogeneous anionic polymerization methods were employed to synthesize a diblock copolymer of the form (A)(n)-b-(B)(m) in which repeat unit A is isoprene, B is n-butylmethacrylate and b is a single unit of 1,1 diphenylethylene. Various physical-chemical characterization methods were employed to determine that the molecular weights of the A and B blocks are 80,000 and 160,000 g/mole respectively. NMR spectra indicated that the poly n-butylmethacrylate moiety is composed predominantly of syndiotactic triads. Thermal analysis and dynamic mechanical testing were used to determine the polyisoprene and poly n-butylmethacrylate glass transition temperatures, which were around -70 and 20 C respectively; the poly n-butylmethacrylate transition observed in the viscoelastic experiments was unusually broad, covering more than 75 C from onset to completion. Thin films of the diblock copolymer prepared by solvent evaporation casting methods, using a variety of solvents and a wide range of solvent evaporation rates, showed a variety of morphologies in transmission electron micrographs. Most notable among these was a structure obtained in rapid-evaporation castings which contained relatively large regions of homogeneous diblock copolymer embedded in the microphase-separated material. While these homogenized regions remain unchanged indefinitely in the bulk material at room temperature, they tend to decompose to the stable microphase-separated material upon heating or upon addition of solvent. (Author)

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