Preparation And Properties Of New Three-Phase Polyurea-Polysiloxane-Polyether Copolymer

Polysilicone-polyurea copolymers have received extensive attention in recent decades, they had important applications in fields of daily life such as fouling-release coatings, auto industry and biomaterials. Investigations of polysilicone-polyurea copolymers has found that in PDMS based polyureas due to the substantial differences in the polarityof PDMS and urea groups, no significant competitive hydrogen bonding or interaction between PDMS and urea were expected, leading to sharp microphase separation and interfaces between the continuous phase. Therefore, introducing new segment into polysiloxane and polyurea backbone to prepare three-phase segmented copolymers could overcome these defects, while research and reports on such project were relatively rare.A new strategy has been proposed to prepare three-phase segmented copolymer in this paper. Preparing polysiloxane-polyether block segments via aza-Michael addition reaction, which could be used as soft segments of polyurea, polyurethane urea. We successfully synthesized acrylatesilane terminated polysiloxane using decarboxylation between (acryloyloxymethyl)dimethylacryloyloxysilane and α, ω-hydroxyl polysiloxane. Fourier transform infrared spectroscopy(FT-IR), proton nuclear magnetic resonance spectroscopy (1H NMR), gel permeation chromatography(GPC) were used to characterize the structure and performances of the segment. FTIR showed that the characteristic absorption peak of acrylate groups emerged in polysiloxane,1H NMR showed that emergence of proton peaks of acryl group in this segment. Combining amine teminated polyoxypropylene(PPO) and acrylatesilane terminated polysiloxane smoothly via aza-Michael addition reaction to prepare block segments. Proton nuclear magnetic resonance spectroscopy (1H NMR), gel permeation chromatography(GPC) and amine value titration method were used to characterize the structure and performances of the block segments.1H NMR showed after reaction, the peaks attributed to vinyl groups completely disappeared and appearance of the brand peaks which were attribute to PPO. Amine value measurement showed there were amine groups in both sides of the segment.After that, using the mixing segments as soft segmensreact with 4,4’-dicyclohexyl methane diisocyanate in solution to prepare polyuria-polysiloxane-polyether three-phase segmented copolymer. FTIR, TGA, dynamic mechanical analysis (DMA), small angle laser light scattering (SAXS), atomic force microscopy (AFM), the stress-strain tests were used to charaterize thermal, morphology and mechanical properties of the copolymers. We found that all the copolymers have excellent micro-phase separation structure and satisfying mechanical properties. This paper has provided a new and efficient process for preparing three-phase polyurea-polysiloxane-polyether copolymers.