Effect of two-phase blend complex viscosity ratio on phase state and properties of acrylate rubber/polyformaldehyde thermoplastic vulcanizate

The blend complex viscosity ratio of acrylate rubber(ACM) phase and polyformaldehyde (POM) phase was regulated by adjusting the proces-sing temperature. The effects of complex viscosity ratio on phase state, physical and mechanical pro-perties, stress relaxation properties, dynamic mecha-nical properties and aging resistance of ACM/POM thermoplastic vulcanizate(TPV) were studied. The results showed that the complex viscosity ratio of two phases increased by 47% when the process temperature increases from 170 ℃ to 190 ℃. The increase of complex viscosity ratio had a significant effect on the shear breakage, agglomeration and phase domain of ACM phase in the system, which could reduce the agglomeration of ACM particles and the tensile stress of TPV. When the complex viscosity ratio was 28.62, the tensile strength of TPV increased to 11.9 MPa, elongation at break increased to 234%, and hysteresis loss was minimized in the temperature range from 80 ℃ to 140 ℃. When the complex viscosity ratio was 23.30, the stress relaxation performance retention rate of TPV was the highest, relaxation rate was the smallest, and hot air and hot oil resistance were the best.