Design, Synthesis Of The Macromolecule Surface Modifier And Application In The Polyurethane/Nano-particles

It is relatively simple and effective way that modified nanoparticles by the "grafting to" method to help polymer nanocomposites to achieve larger-scale. The first step is macromolecular surface modifiers were designed and synthesized, then surface of nano-particles was modified through the grafting reaction between the reactive functional group on the macromolecular chain and active groups on the surface of inorganic nano-particles.Finally, the modified nano-particles added in to polymer for improve its performance.A new type of macromolecular surface modifier that reactive functional group contained the end of molecular chain was designed and synthesized, which it have a good modification effect and dramatically reduce the cost of its raw materials.In this thesis,we chose several modified nano-particles to trial manufacture PU/nano-particles.This thesis has four chapters:The first chapter is mainly to introduce the latest research trend of polymer nano-composites, surface modification of inorganic nanoparticles,polyurethane nanocomposites and their application.In the last part of this chapter my expermental design was ptesent.In the second chapter,A two-stage process was developed to synthesize the low molecular weight copolymer of monofunctional group which is located at one end of the polyacrylic ester chain. Firstly, monohydroxyl-terminated copol-ymers((?)) were synthesized from methyl methacrylate(MMA) and butyl acrylate(BA) by radical adjusting copolymerization using a functional chain-transfer agent,2-mercaptoeth-anol(2-ME),and very low initiator lever,azobis-isobutyronitrile(AIBN).Solutions of 2-ME and AIBN in the monomers having a monomers/2-ME/AIBN mole ratio of 1000/25/1 were added continuously during 2.5h to refluxing toluene at 110℃,Stirring and refluxing were continued throug-hout the adddition and for 4h thereafter.Secondly,the monoisocyanate-terminated copolymers ((?)) was obtained by reaction of toluene-2,4-diisoc-ynate(TDI) and(?) or the monocarboxyl-terminated copolymers was obtained by reaction of maleic anhydride (MAH) and The structure,molecular weight and thermal properties of tar-get products were characterized by 1H NMR,13C NMR,FT-IR,GPC and TGA.As the results showed the products obtainted are coincident with the target molec-ulars designed for synthesis which are monofunctional group of termination po-lyacrylic ester and the number-average molecular weight(?)of the product is about 4500. DSC and TGA show that there is only one Tg and the main wei-ght loss is between 300 and 450℃.In the chapter three, the macromolecular modifier((?)) was used for surface modification of nano-particles (Si3N4, SiO2 and CaCO3).The properties of modified nano-particles were investigated by FTIR,TGA,Size distribution analyzer, dispersion stabilizition,TEM,Contact angle and SEM.The results showed that macromolecular modifier bonded covalently on the surface of nano-particles and an organic coating layer was formed after modification; The average particle size of nano-Si3N4 had diminished obviously and possessed good dispersibility; Contact angle investigated that the hydrophile of modified nano-particles were decreased. And TGA showed that stearic acid modified on the surface of nano-CaCO3 is better than (?).In the chapter four, PU/nano-particles composites are studied by filling modified nano-particles.The difference is that PU leather was filled nano-SiO2 modified by (?) stock solution of foamed sole was filled nano-CaCO3 modified by stearic acid. The mechanical properties and wear resistance of the PU nano-composites were investigated. The results indicated that these properties of PU leather were improved due to the modified nano-SiO2 with macromolecular modifier and PU/nano-CaCO3 compositematerial's cost dramatically reduce,But their performances were undiminished.