Ma Lifeng, Yang Wei, Guo Hui
School of Mechanical and Automotive Engineering, Shanghai University of Engineering Science, Shanghai 201620, China.
College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, China.
Polymers (Basel). 2019 Aug 21;11(9):1375. doi: 10.3390/polym11091375.
As a special class of "green" elastomers, thermoplastic vulcanizates (TPVs) have been widely used in industries due to the combination of the excellent resilience of conventional elastomers and the easy recyclability of thermoplastics. Here, the morphology evolution of TPVs based on polyamide 6/ethylene-propylene-diene rubber (PA6/EPDM) blends was investigated by varying the content of the curing agent, phenolic resin (PF). With the incorporation of 6 wt% PF, the gel content of the EPDM phase reaches a high value of 49.6 wt% and a typical sea-island structure is formed with EPDM domain in a micro-nano size. The dynamic rheology behaviors of TPVs showed that with the curing degree of EPDM phase increasing, a denser network of EPDM particles is formed in PA6 matrix. Additionally, a lower crystal degree and crystal peak temperature are observed, indicating that there exists a growth restriction of PA6 crystal plate induced by a thinner plastic layer between the adjacent EPDM particles. However, the crystal form of PA6 is not changed with the increasing curing degree of the EPDM phase. This study provides an effective strategy to realize a new kind of TPVs, which can be easily introduced into industrial applications.
作为一类特殊的“绿色”弹性体，热塑性硫化橡胶（TPV）由于兼具传统弹性体的优异回弹性和热塑性塑料的易回收性，已在工业中得到广泛应用。在此，通过改变固化剂酚醛树脂（PF）的含量，研究了基于聚酰胺6/乙丙二烯橡胶（PA6/EPDM）共混物的TPV的形态演变。加入6 wt%的PF后，EPDM相的凝胶含量达到49.6 wt%的高值，并形成了典型的海岛结构，其中EPDM域呈微纳米尺寸。TPV的动态流变行为表明，随着EPDM相固化程度的增加，PA6基体中形成了更致密的EPDM颗粒网络。此外，观察到较低的结晶度和结晶峰温度，这表明相邻EPDM颗粒之间较薄的塑料层会导致PA6晶片的生长受限。然而，PA6的晶型并未随EPDM相固化程度的增加而改变。本研究提供了一种实现新型TPV的有效策略，可轻松引入工业应用。
