聚合物在壓力下的流動誘導結(jié)晶
發(fā)布時間:2018-03-27 15:10
本文選題:壓力 切入點:流動場 出處:《高分子通報》2017年10期
【摘要】:流動誘導聚合物結(jié)晶研究很少在壓力場下開展,其原因是壓力下流動誘導聚合物結(jié)晶對實驗設備要求較高。然而,實際加工中不僅存在流動場,還有壓力場。為此,作者課題組利用自制的裝置對壓力下流動誘導聚合物結(jié)晶開展了系統(tǒng)研究,發(fā)現(xiàn)其結(jié)晶行為與常壓的流動誘導結(jié)晶有較大差別。等規(guī)聚丙烯(iPP)在壓力和剪切場下可形成獨特取向球形晶體形態(tài)。在短時間內(nèi)(30min),iPP片晶可快速增厚,形成熔點接近平衡熔點的厚片晶(近180℃),其原因是在壓力和流動場協(xié)同作用下,片晶增厚活化能快速減小。同時,從研究結(jié)果也獲得了添加β成核劑的iPP體系在壓力和流動場下形成β晶的窗口條件。對聚乳酸(PLA)的研究也發(fā)現(xiàn)了相似的片晶快速增厚規(guī)律。另外,在壓力和流動場下,可直接從PLA熔體中獲得可增韌PLA的β晶。研究成果為實際加工中的聚合物形態(tài)結(jié)構(gòu)調(diào)控提供了理論和實驗依據(jù)。
[Abstract]:The research of flow-induced polymer crystallization is seldom carried out under pressure field, because the flow induced polymer crystallization under pressure requires high experimental equipment. However, there is not only flow field but also pressure field in practical processing. The author's team has carried out a systematic study of flow-induced polymer crystallization under pressure by using a self-made device. It is found that the crystallization behavior of IPP is different from that of fluid-induced crystallization under atmospheric pressure. Ipp can form a unique oriented spherical crystal form under the pressure and shear field. In a short period of time, the IPP wafer can be rapidly thickened. The formation of thick wafer crystals with melting point close to equilibrium melting point (nearly 180 鈩,
本文編號:1672049
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