排序方式: 共有6条查询结果,搜索用时 46 毫秒
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热处理对聚己二酸丁二醋多晶结构和降解行为的影响 总被引:1,自引:0,他引:1
通过熔融结晶并结合退火处理方法得到多晶结构的聚己二酸丁二酯(PBA)及具有不同热历史的热力学稳定的a晶型,采用广角X射线衍射仪(WAXD)、原子力显微镜(AFM)和差示扫描量热仪(DSC)研究了PBA的多晶结构、晶体尺寸和结晶形貌,跟踪了退火处理PBA的生物降解行为.结果表明,分子链在相同晶格排列中围绕c轴空间取向的不... 相似文献
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针对聚合物流变学多学科交叉性以及较强的理论性和实践性的特点,结合作者的教学实践,总结了在聚合物流变学教学中的几点体会。提出在该门功课讲授过程中注重教学内容与教学方法的形象化,培养学生的学习兴趣;通过开设实验课,放映实践过程录像、图片等形式将理论与实践结合的教学方法,消除学生学习该门课程的抽象感。此外,通过教学实例提出在... 相似文献
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“结构、性能及分子运动”三者之间制约关系是高分子物理的核心内容,其中“分子运动”的知识最为抽象,是学生学习的难点内容。针对此问题,融入教师科研成果,设计了“形状记忆的聚乳酸/聚碳酸亚丙酯共混材料的结构与性能”综合实验。通过该实验,学生系统而具体的理解“结构与分子运动”、“分子运动与力学性能”、“分子运动与形状记忆功能”的知识,掌握热分析、扫描电镜、力学性能以及形状记忆功能的实验技术,体会高分子基础理论在创造新材料中的典型应用。 相似文献
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The effects of graphene oxide(GO) with polar groups and functionalized GO(f GO) with nonpolar groups on the isothermal crystallization of poly(L-lactide)(PLLA) were compared. Functionalized GO was obtained by grafting octadecylamine and characterized by FTIR, WAXD and TGA. Isothermal crystallization kinetics of PLLA/GO and PLLA/f GO nanocomposites were investigated by combining DSC data and Avrami equation. The results showed that f GO could improve PLLA crystallization rate more obviously than GO. By analyzing the morphology obtained from POM, SEM and TEM, it was found f GO with large layer space dispersed better in PLLA and supplied more nucleation sites than GO. Therefore, for the multilayer graphene, increasing the layer spaces is important to improve its dispersion in polymers, which will cause the crystal kinetics changing of polymers. 相似文献
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Miscibility, isothermal crystallization kinetics, and morphology of poly(L-lactide)/poly(trimethylene carbonate)(PLLA/PTMC) crystalline/amorphous blends were studied by differential scanning calorimetry(DSC) and optical microscopy(OM). The heterogeneity of OM images and an unchanged glass transition temperature showed that PLLA was immiscible with PTMC. During isothermal crystallization, the crystallization rate of PLLA improved when the PTMC content was low(≤ 20%). However, when the PTMC content was high(≥ 30%), the crystallization rate decreased significantly. The reason of these nonlinear changes in crystal kinetics was analyzed according to the nucleation and growth process by virtue of a microscope heating stage. The isothermal crystallization morphologies of the blends were also studied by polarized optical microscopy and the results confirmed the conclusions obtained from crystallization kinetics. 相似文献
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