Preparation And Properties Of Polystyrene/Copper Nanoparticles Composite

Polymer/nanoparticle compos ites not only have the excellentprocessing performance of a polymer but also have the specialproperties of nanoparticles with surface effect as well as size effec t,and therefore have attracted much attention from material researchers.Actually, the researches and preparations of polystyrene/coppernanoparticle comp osite would pave the way for the preparation ofZ-pinch silk array materials in the inertial confinement fusion (ICF)experiment.A copper nanoparticles (CuNPs) colloid was synthesized viasolution che mical reduction method. The influences of reactionte mperature, as well as the dosages of poly (N-vinylpyrrolidone)(PVP),cetyltri methyl ammonium br omide (CTAB), and hydrazine hydrate onthe sizes and the size distributions of CuNPs were studied. The optima lconditions are:3.0g of PVP,1.0g of CTAB,0.06M of hydrazine hydrate,a reaction temperature of70℃, and a reaction time of2hours. Underthese conditions, a CuNPs colloid with good dispersity and stabilitywas synthesized. The CuNPs were characterized by UV-Visibleabsorption spectra (UV-Vis), X-ray diffraction (XRD), fouriertransform infrared spec troscopy (FTIR), transmission electronmicroscopy (TEM), and thermogravimetric analysis (TG). Data showthat the CuNPs have a particle size of10～20nm, and belong to cubiccrystal system. On the surface of the CuNPs was adsorbed a s mallamount of PVP, which could prevent the CuNPs from aggregation andoxidation.A polystyrene/copper nanoparticles (PS/CuNPs) composite wassynthesized via in situ emulsion polymerization. The influences ofreaction temperature, reaction ti me, and dosage of initiator on theconversion of styrene, molecular weight, and polydispersity indexes ofPS were researched. The optimal conditions for PS and PS/CuNPspreparation are:3.0g of PVP,1.0g of CTAB, an initiator amount of2.0%(w/w), a reaction temperature of85℃, and a reaction time of7 hours. Under these conditions, the highest conversion of styrenemonomer is90.2%. The PS/CuNPs composite was characterized byUV-Vis, XRD, FTIR, TG, GPC, TEM, and FESEM. TEM shows that thesize of the PS/CuNPs composite is10～40nm. During thepolymerization reaction, the morphology and size of the CuNPs did notchange, and no aggregation was observed. Thus, a uniform dispersionof the CuNPs in polystyrene matrix has achieved successfully. Theaverage molecular weight of PS matrix in the composite is more than2×10~5, with a polydispersity index of about2.0. TG shows that thePS/CuNPs composite has a better thermal stability than that of virginpolystyrene.In conclusion, a highly stable and dispersive CuNPs colloid wassynthesized via solution chemical reduction method. Then, thepolymerization of styrene was carried out on the surface of CuNPs viain situ e mulsion polymerization, yielding the PS/CuNPs composite. Inthe PS/CuNPs composite, CuNPs were unifor mly dispersed inpolystyrene matrix. Generally, the study in this paper has a certaintheoretical significance and practical value.