Effects of the sintering temperature on the superior cryogenic toughness of ultra-high molecular weight polyethylene (UHMWPE)

Eminent differences in cryogenic toughness of ultra‐high molecular weight polyethylene with different entanglement densities

“…Therefore, we can attribute the better cryogenic properties of GUR 4012 to its higher entanglement densities, which has been reported in our previous study. 5 GUR 4012 has a wider distribution of the powder size than that of GUR 400 Fine (Figure 5), so it can achieve greater powder packing when the smaller particles fill the voids between the larger powders after being first pressurized at 85 C. Previous studies have shown that more densified samples have fewer defects during the molding process, so the mechanical properties of the products could be better. 28 In the second stage of the molding process, we chose the molding temperature of 200 C. At this high temperature, the process of diffusion and re-entanglement of UHMWPE chains can appear both inner and at the interface of particles.…”

“…The sintering-mold samples were completely prepared through the previous protocol and homemade equipment. 5 In brief, the molding process of the sample is mainly divided into three steps: the original particle densification (performed at 85 C), pressurized insulation and melting, and pressurized cooling. From the previous study, 5 it was found that the product sintered at 200 C demonstrated the best performance, so the sintering temperature chosen in this study was 200 C. In addition, all the other molding parameters followed with the previous study.…”

“…Ultra-high molecular weight polyethylene (UHMWPE) has distinguished mechanical properties as well as wear resistance at room temperature, [1][2][3][4] and at the same time, its glass transition temperature is extremely low, so its excellent mechanical properties can still be maintained under low-temperature conditions. 5 In addition, the composite materials applied to cryogenic engineering may crack at ultra-low temperature after long-term service due to the difference in thermal expansion coefficient, [6][7][8] but UHMWPE can effectively avoid this problem since it is a homopolymer. These advantages make it become material with great potential for cryogenic applications.…”

Mechanical properties and microstructure of polychlorotrifluoroethylene toughened by polyamide 11 based on intermolecular interaction

“…Presently, the increasing demand for clear energy such as liquid hydrogen and liquefied natural gas 1,2 has driven vigorous development of downstream cryogenic storage and transportation materials, 3,4 and some special polymers including polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE) and ultra-high molecular weight polyethylene are potentially emerging as the safety, lightweight and economic choices. [5][6][7] Among them, PCTFE is the only one that can be effectively melt-processed. Compared with other fluoropolymers, substitution of one fluorine atom in repeat unit by chlorine atom in PCTFE not only retains the chemical inert character, but also enhances thermoplasticity, mechanical performance, and barrier property.…”

“…Presently, the increasing demand for clear energy such as liquid hydrogen and liquefied natural gas 1,2 has driven vigorous development of downstream cryogenic storage and transportation materials, 3,4 and some special polymers including polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE) and ultra‐high molecular weight polyethylene are potentially emerging as the safety, lightweight and economic choices 5–7 . Among them, PCTFE is the only one that can be effectively melt‐processed.…”