Formation and stabilization of crystal nuclei in isotactic polybutene-1 aged below glass transition temperature
Formation and stabilization of crystal nuclei in isotactic polybutene-1 aged below glass transition temperature
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DOI：
10.1016/j.polymer.2020.122293
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发表时间：
2020-03
期刊：
影响因子：
4.6
通讯作者：
Peiru Liu;Yanhu Xue;Yongfeng Men
中科院分区：
文献类型：
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作者：
Peiru Liu;Yanhu Xue;Yongfeng Men
玻璃态全同立构聚丁烯-1（iPB-1）在玻璃化转变温度（Tg）以下老化，由于晶核的促进，导致随后的等温结晶显着加速。用快速扫描芯片量热法研究了在低于Tg时效和加热到晶化温度过程中晶核的形成和发展。随着时效时间的延长，晶核的大小和稳定性发生变化。低于Tg的短时效只能诱导小尺寸的原子核，在高于Tg的加热过程中，如果加热速率不够高，这些原子核可以长大成更大的稳定原子核。随着低于Tg时效时间的延长，也可形成较大的稳定晶核，其数量不断增加，直至达到最大值。这些结果表明，非合作的局部运动，而不是合作的节段运动的玻璃iPB-1负责在低于Tg老化过程中的晶核的形成。
Aging of glassy isotactic polybutene-1 (iPB-1) below the glass transition temperature (Tg) leads to remarkable acceleration of the subsequent isothermal crystallization due to the promotion of crystal nuclei. The formation and development of crystal nuclei during aging belowTgand during heating to the crystallization temperature have been probed by fast scanning chip calorimetry. The size and stability of the crystal nuclei change with the aging time. A short aging belowTgcan only induce nuclei with small sizes which can grow into bigger stable ones during the heating process aboveTgif the heating rate is not high enough. With a prolonged aging time belowTg, bigger stable nuclei can also be developed, and its number increases till reaches a maximum value. These results suggest that noncooperative local motions rather than cooperative segmental motions in glassyiPB-1 are responsible for the formation of crystal nuclei during aging belowTg.