Journal of South China University of Technology(Natural Science Edition) ›› 2022, Vol. 50 ›› Issue (8): 144-154.doi: 10.12141/j.issn.1000-565X.210672

Special Issue: 2022年材料科学与技术 2022年环境科学与技术

• Materials Science & Technology • Previous Articles    

Influence of Pulse Vibration Frequency on Structure and Properties of UHMWPE Molded by Pulse Vibration Molding

HU Songxi1,2  FENG Yanhong1  YIN Xiaochun1  ZOU Xinliang1   

  1. 1.Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing / National Engineering Research Center of Novel Equipment for Polymer Processing / The Key Laboratory of Polymer Processing Engineering of the Ministry of Education,South China University of Technology,Guangzhou 510640,Guangdong,China
    2.School of Intelligent Engineering,Shaoguan University,Shaoguan 512005,Guangdong,China
  • Received:2021-10-22 Online:2022-08-25 Published:2022-01-14
  • Contact: 冯彦洪(1976-),女,博士,教授,主要从事高分子材料加工新技术与新装备研究。 E-mail:yhfeng@scut.edu.cn
  • About author:胡松喜(1983-),男,博士生,主要从事高分子材料加工新技术与新装备研究。E-mail:287370018@qq. com
  • Supported by:
    the National Key Research and Development Plan(2016YFB0302300)

Abstract:

The existing static molding methods of ultra-high molecular weight polyethylene (UHMWPE) generally have the problems of long forming cycle, high energy consumption, easy thermal decomposition and so on, and the primary phase characteristic structure of their products has been completely eliminated, leading to failure in keeping good mechanical properties and excellent wear resistance at the same time. Therefore, UHMWPE products (PVM-UHMWPE) were prepared efficiently at low temperature by pulse vibration molding (PVM) technology in this paper, and the influence of pulse vibration frequency during molten hot pressing stage on structure and properties of UHMWPE products were studied. The results show that PVM can promote the interfacial fusion of particles at low molding temperature by friction between UHMWPE particles, and effectively preserve the structure characteristics of high regularity and crystallinity of nascent phase to increase the crystallinity and lamellae thickness. With the increase of pulse vibration frequency during molten hot pressing stage, the effect of pulse vibration increases, and this can improve the quality of particles interface consolidation. The yield strength, tensile modulus, break strength and work to failure of PVM-UHMWPE are all improved. However, when the frequency exceeds 3.0 Hz, the damage degree of such structure characteristics as high regularity and crystallinity of UHMWPE is aggravated by the effect of pulse vibration, and the overall crystallinity and melting temperature are reduced, resulting in the decrease of tensile modulus without further improving fracture toughness. As compared with sample CM-210 ℃-60 min with double molding cycle and 40 ℃ higher molding temperature, yield strength and tensile modulus of PVM-UHMWPE with a molding temperature of 170 ℃ and a pulsation frequency of 3.0 Hz (PVM-170 ℃-3.0 Hz) is improved by about 9% and 23%, respectively, and wear rate and wear index decrease by about 24% and 22%, respectively. That is, as compared with sample CM-210 ℃-60 min, sample PVM-170 ℃-3.0 Hz has higher mechanical strength and be-tter wear resistance.

Key words: ultra-high molecular weight polyethylene, high-efficiency low-temperature molding, pulse vibration molding, pulse vibration frequency, crystallinity degree, mechanical property, wear-resisting property

CLC Number: