Formation and reinforcing effect of epitaxial oriented crystallization of polyethylene induced by self‐assembly nucleating agent under stress. Issue 7 (22nd December 2021)

• Record Type: Journal Article
• Authors: Wu, Buyong; Kong, Chen; Cai, Yudong; Ye, Lin; Chen, Shangtao; Li, Shuanhong; Zhao, Xiaowen
• Is Part Of: Polymer international. Volume 71:Issue 7(2022)
• Page Start: 817
• Page End: 828
• Publication Date: 2021-12-22
• Subjects: polyethylene pipe -- self‐assembled nucleating agent -- epitaxial oriented crystallization -- hybrid shish‐kebab structure -- self‐reinforcement; Plastics -- Periodicals; Polymers -- Periodicals; Polymerization -- Periodicals; 547.7
• DOI: 10.1002/pi.6347
• Languages: English
• ISSNs: 0959-8103

Abstract

Abstract: A rare earth nucleating agent (RENA) was introduced to fabricate polyethylene (PE) pipe resin, which self‐assembled into various structures in PE melt during processing and further induced PE molecules to epitaxially crystallize on its surface to form, among others, a hybrid shish‐kebab crystalline structure due to good crystallographic matching between RENA and PE. Under stress, the shish structure formed by needle‐like RENA assembly arranged preferentially along the drawing direction, which was beneficial for an orderly arrangement of PE chains epitaxially crystallizing on its surface in the process of stress‐induced recrystallization and thus promoted the formation of a dense oriented crystalline structure with a large number of shish structures, resulting in higher degree of crystallinity and orientation, and lower long period and lateral size of lamellae than those of PE sample. By orientation, compared with PE sample at the same draw ratio, PE‐RENA samples showed much higher tensile strength and modulus. Especially, the oriented PE‐RENA pipes showed an approximately 96% and 100% increase in tensile strength along the hoop direction and internal pressure resistance, respectively, compared with unoriented pipe sample. This work provides a facile method for fabricating highly enhanced PE pipes with wide application prospects. © 2021 Society of Industrial Chemistry. Abstract : A rare earth nucleating agent was introduced into polyethylene pipe resin, which self‐assembled into needle‐like assembly and induced epitaxial crystallization of polyethylene to form highly oriented hybrid shish‐kebab structure under stress.