共聚物
聚酰胺
高分子化学
无定形固体
材料科学
氧化物
玻璃化转变
氢键
相(物质)
聚合物
化学
结晶学
分子
复合材料
有机化学
冶金
作者
Yu Wang,Jianming Shao,Ping Zhu,L. Wang,Du-Jin Wang,Xia Dong
出处
期刊:Macromolecules
[American Chemical Society]
日期:2022-08-26
卷期号:55 (17): 7683-7694
被引量:3
标识
DOI:10.1021/acs.macromol.2c01194
摘要
The effect of composition on the Brill transition of polyamide-based copolymers was systematically investigated with the synthesized polyamide 1012 (PA1012) multiblock poly(tetramethylene oxide) (PTMO) copolymers. By using the X-ray scattering and infrared spectroscopy techniques, it was found that the amorphous PTMO segments accelerated the reorganization of hydrogen sheet (H-sheet) structures of PA1012 segments during rapid cooling from the melt, resulting in an α-phase with a higher crystal perfection index (CPI) for a lower PA1012 content (WPA) copolymer. For low-WPA copolymers, the α-phase is completely transformed to the γ-phase at a lower Brill temperature (TB) at a given CPI, which is attributed to the enhanced chain mobility by the PTMO segments. All the studied samples (WPA in the range of 1.00 to 0.32) are superimposed to form a master curve of TB/TB,CPI=1 = 0.9 × CPI + 0.08, where TB,CPI=1 is the theoretical TB for each sample at its corresponding perfect H-sheet structure. The results imply that the thermodynamic mechanism of Brill transition in the PA1012 homopolymer and PA1012-PTMO copolymer is equivalent. Moreover, this master curve can be used to quantitatively estimate the TB of PA1012-PTMO copolymers with a given composition and is expected to be applied in polyamide-based copolymers composed of different comonomers by determining their own characteristic parameter of TB,CPI=1.
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