Preparation and compatibility mechanism study of the polyurethane-polysiloxane copolymer with tunable polysiloxane content for TPU/MVQ blends with comfortable texture

Abstract

Thermoplastic polyurethane (TPU)/methyl vinyl silicone elastomer (MVQ) blends exhibit the advantages of excellent texture and biocompatibility, finding applications in wearable materials, electronic devices, biomedical materials, and so on. However, the TPU/MVQ blending system is a somewhat thermodynamically incompatible system, with large polarity differences and weak interface interaction during blending. As an effective compatibilizer applied in industry, the structure of polyurethane-polysiloxane copolymer (PU-PDMS) compatibilizers can affect the phase and interface of the blends as well as the performance. However, the influence of their structure on the phase and interface of the blends is still unknown. In this study, PU-PDMS compatibilizers with varying polydimethylsiloxane (PDMS) content were prepared by using PDMS and polytetrahydrofuran (PTMG) as the mixed soft segments and adjusting the molar ratio of PTMG and PDMS. The influence of structure of the PU-PDMS compatibilizer on the morphology, interface, and mechanical properties of the obtained TPU/MVQ was investigated, and the compatibilization mechanism is proposed. Results indicated that the compatibility effect is better when the PDMS content in the PU-PDMS copolymer compatibilizer is a medium value of 80%, and the size of the MVQ dispersed phase is only 2.5 ± 1.0 μm with 10 wt% compatibilizer addition. This preparation and compatibilization mechanism study of PU-PDMS will be beneficial for developing the TPU/MVQ thermoplastic vulcanizates (TPV) in industry and provide a guideline for the design and preparation of efficient compatibilizers for other immiscible blending preparations.