Preparation And Properties Of Polyurethane Hybrid Materials Containing Bifunctional Poss

The introduction of POSS into the materials by chemical reaction can both disperse at the nanoscale and modified at the molecular level.In this paper,a bifunctional POSS was synthesized and introduced into the main chain of the polymer molecular chains.The effects of different POSS contents on the properties of the materials were studied.The main research contents are as follows:(1)Dihydroxyhexavinyl POSS(POSS-2OH)was synthesized,and the R value was set to 1.1.POSS-2OH was introduced into the main chain of the polyurethane molecular chains to prepare epoxy resin E51/polyurethane with POSS in the main chain composites.With the introduction of POSS-2OH,the maximum degradation rate is reduced,the char residual is increased,so thermal stability is increased.When 10 wt%of POSS-20H was added,the tensile strength was 11.7 MPa,which was 3.4 times higher;the dielectric constant was 3.48,and the dielectric loss was 0.06.The water contact angle gradually increased,and when 20 wt%of POSS-2OH was added,the contact angle reached 111.3°.(2)The R value was set to 1,and polyurethane with POSS in the mian chain was synthesized by the chain extension method,and the TPU/polyurethane with POSS in the mian chain composites were prepared.The introduction of POSS-2OH improved thermal stability but crystallization properties decreased.As the POSS-2OH wt%increased,the dielectric constant and dielectric loss decrease at the same time,The tensile strength and elongation at break increase simultaneously.POSS-20H acts the reinforcing agent and toughening agent.The water contact angle gradually increases from 90.40 to 114.2°,and the hydrophobic performance was improved.(3)The crosslinking organic-inorganic hybrid polyurethane was synthesized by copolymerization.After the introduction of POSS-2OH,the thermal properties of the material were greatly improved,Td5 increased by about 65?,and the char residual was as high as 55.40%.When 20 wt%of POSS-20H was added,the dielectric constant is the lowest,2.98,the dielectric loss is also the lowest,0.01,and the tensile strength is 45.33 MPa,which is increased by 3 times.The water contact angle gradually increases and the material achieves a transition from hydrophilic to hydrophobic.POSS-20H particles were aggregated in the matrix but still were transparent.