Effect of PTFE on Properties of PE-UHMW

 

In order to obtain ultra high molecular weight polyethylene (PE-UHMW) matrix composites which get high wearresistance and high heat resistance , and the poly tetrafluorethylene (PTFE) was modifed to improve the wear resistance and heatresistance of PE-UHMW. The test results show that the Shore hardness of the composite reach the highest that is 67.08, and thewear resistance is the best when the mass fraction of PTFE is 5%, the friction coeficient to 15CrMoV steel is 0.235 and the wearrate is 0.081 4%, and the thermal deformation temperature of the composite is increased by 21% when the load is 10.0 N and thedeformation amount is 0.06 mm. Under the action of KH-~550 coupling agent, the PTFE can achieves a uniform distribution in the PE-UHMW matrix, and the formation of dense binding. With the increase of PTFE content, the creep of the composites is graduallyincreased.

 

Since its inception, ultra-high molecular weight polyethylene (PE-UHMW) has been widely used in mechanical textile, medicine and other fields with its excellent physical and mechanical properties, becoming an engineering plastic that can replace metal materials. PE-UHMW has good impact resistance, wear resistance, chemical corrosion resistance, self-lubrication and other properties. However, PE-UHMW's low hardness and thermal deformation temperature defects cannot meet some high requirements of field applications. At present, modification methods of PE-UHMW mainly focus on chemical modification and physical modification. People often add organic and inorganic particles or fibers to PE-UHMW to improve its performance. By contrast, organic modifiers are easier to form firm bonds with PE-UHMW molecular chains.

 

Polytetrafluoroethylene (PTFE) holds the title of "the king of plastic, PTFE, with its excellent corrosion resistance, wear resistance, low friction coefficient, is only 1/5 of the polyethylene, between 0.01 ~ 0.10, as additives to improve the PE-UHMW abrasion resistance and heat resistance. It has obvious effect, Fang Zheng equality of polyoxymethylene, polyamide, PTFE linear low density polyethylene (PE-LLD) such as blending modification, the results found that Adding appropriate amount of modified PTFE can significantly improve the compatibility between PTFE and polymer. When PE-LLD is modified with PTFE, the mechanical properties, processing properties and stability of composites are greatly improved, and the friction coefficient is significantly reduced. PTFE was selected to blend and modify PE-UHMW in order to prepare composites with excellent wear resistance and heat resistance, reduce the friction coefficient of PE-UHMW and expand its application field.