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 ultrafme 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.

Polyurethane-polysiloxane Copolymer Compatibilized SiR/TPU TPV with Comfortable Human Touch Toward Wearable Devices

Because of its softness,wear resistance,biocompatibility,extremely comfortable human touch,thermoplastic vulcanizate(TPV)comprised of silicone rubber(SiR)and thermoplastic polyurethane(TPU)(SiR/TPU TPV)is especially suitable for wearable intelligent devices.Nevertheless,developing good compatibilizer is still required to prepare high performance SiR/TPU TPV.In this study,three kinds of polyurethane-polysiloxane copolymer(PU-co-PSi)with different contents of polysiloxane segment were selected,and their compatibilization effect on SiR/TPU blends was studied using nanomechanical mapping technique of AFM.The results show that using PU-co-PSi with the highest content of polysiloxane segment(PU-co-HPSi),the interface thickness largely increases,and the average size of SiR dispersed phase largely decreases,indicating its good compatibilization effect.By using PU-co-HPSi as compatibilizer,SiR/TPU TPV with a fine SiR dispersed phase and good mechanical performance were successfully prepared.The mechanism on the compatibilization effect of these PU-co-PSi on SiR/TPU TPVs was revealed.