Yilei Zhu

One-step process to make electrically conductive thermoplastic vulcanizates filled with MWCNTs

Electrically conductive thermoplastic vulcanizates (TPVs) filled by multi-walled carbon nanotubes (MWCNTs) are prepared by a simple one-step melt mixing process, based on linear low density polyethylene (LLDPE) and ultrafine full-vulcanized rubber particles (UFRP). An ideal morphology with controlled localization of MWCNTs in continuous LLDPE matrix and appropriate size of finely-dispersed UFRP can be achieved at the same time. The controlled localization of MWCNTs in the continuous phase facilitates the formation of conductive pathway, and thus the volume resistivity of the as-prepared LLDPE/UFRP/MWCNTs thermoplastic vulcanizates is significantly decreased. The results show that both the blend ratio of LLDPE/UFRP and the loading of MWCNTs have remarkable effect on the volume resistivity. Significantly, the electrically conductive TPVs exhibit good mechanical properties duo to the fine dispersion of UFRP in LLDPE. The added MWCNTs are capable of imparting reinforcement effects to thermoplastic vulcanizates with just a slight loss of stretchability and elasticity.

Conductive polymer nanocomposites containing in situ ultra-fine metal particles

A conductive polymeric composite containing in situ ultra-fine metal particles is prepared by melt blending. Incorporation of elastomeric nano-particles and carbon nanotubes hinders the coalescing of metal particles and causes a shift to the breakup direction in the breakup/coalescence equilibrium of metal particles. The prime metal particles (about 26 μm) are in situ converted into the ultra-fine metal particles (UFMP, about 932 nm). The network of carbon nanotubes has been improved due to in situ ultra-fine metal particles and the percolation threshold of the composite with 1.96 vol% UFMP is only 0.25 vol% carbon nanotubes.