Effect of Rubber Nanoparticle Agglomeration on Properties of Thermoplastic Vulcanizates during Dynamic Vulcanization

Hanguang Wu; Ming Tian; Liqun Zhang; Hongchi Tian; Youping Wu; Nanying Ning; Guo-Hua Hu

doi:10.3390/polym8040127

Effect of Rubber Nanoparticle Agglomeration on Properties of Thermoplastic Vulcanizates during Dynamic Vulcanization

Polymers (Basel). 2016 Apr 15;8(4):127. doi: 10.3390/polym8040127.

Authors

Hanguang Wu¹, Ming Tian^{2

3}, Liqun Zhang^{4

5}, Hongchi Tian⁶, Youping Wu^{7

8}, Nanying Ning^{9

10}, Guo-Hua Hu¹¹

Affiliations

¹ Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing 100029, China. hanguangwu.1988@163.com.
² Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing 100029, China. tianm@mail.buct.edu.cn.
³ State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China. tianm@mail.buct.edu.cn.
⁴ Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing 100029, China. zhanglq@mail.buct.edu.cn.
⁵ State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China. zhanglq@mail.buct.edu.cn.
⁶ Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing 100029, China. 13964511068@163.com.
⁷ Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing 100029, China. wuyp@mail.buct.edu.cn.
⁸ State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China. wuyp@mail.buct.edu.cn.
⁹ Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing 100029, China. ningny@mail.buct.edu.cn.
¹⁰ State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China. ningny@mail.buct.edu.cn.
¹¹ Laboratory of Reactions and Process Engineering, University of Lorraine-CNRS, Nancy 54500, France. guo-hua.hu@univ-lorraine.fr.

Abstract

We previously reported that the dispersed rubber microparticles in ethylene-propylene-diene monomer (EPDM)/polypropylene (PP) thermoplastic vulcanizates (TPVs) are actually agglomerates of rubber nanoparticles. In this study, based on this new understanding of the microstructure of TPV, we further revealed the microstructure-properties relationship of EPDM/PP TPV during dynamic vulcanization, especially the effect of the size of rubber nanoparticle agglomerates (d_n), the thicknesses of PP ligaments (ID_poly) and the rubber network on the properties of EPDM/PP TPV. We were able to simultaneously obtain a high tensile strength, elongation at break, elastic modulus, and elasticity for the EPDM/PP TPV by the achievement of a smaller d_n, a thinner ID_poly and a denser rubber network. Interestingly, the effect of d_n and ID_poly on the elastic modulus of EPDM/PP TPV composed of rubber nanoparticle agglomerates is different from that of EPDM/PP TPVs composed of rubber microparticles reported previously. The deformation behavior of the TPVs during stretching was studied to understand the mechanism for the achievement of good mechanical properties. Interestingly, the rubber nanoparticle agglomerates are oriented along the tensile direction during stretching. The TPV samples with smaller and more numerous rubber nanoparticle agglomerates can slow down the development of voids and cracks more effectively, thus leading to increase in tensile strength and elongation at break of the EPDM/PP TPV.

Keywords: elasticity; melt processability; morphological evolution; tensile properties; thermoplastic vulcanizate.