Study On Blends And Foam Materials Of NR-g-(GMA-co-St)/PVC

A grafting modified Natural Rubber[NR-g-(GMA-co-St)] was prepared by melt grafting using glycidyl mechacrylate(GMA) as a grafting monomer, styrene(St) as a grafting co-monomer, dicumyl peroxide(DCP) as a radical initiator in single-screw extruder. Effect of mass ratio of GMA, St, DCP and grafting temperature on grafting degree of NR and mechanical properties of NR-g-(GMA-co-St) were studied. Grafting degree was characterized by FTIR. The results showed that, grafting degree was the highest and vulcanized NR-g-(GMA-co-St) had the best mechanical properties when GMA/St/DCP was 8/4/0.3 and grafting temperature was 160℃. Moreover, addition of St significantly accelerated GMA grafting onto NR, could effectively control the decomposition of NR. Analysis of FTIR proved that GMA did graft ontoα-H and double-bonds of NR.[NR-g-(GMA-co-St)]/ poly vinyl-chlorid(ePVC) blends were prepared by dynamical vulcanization. Effect of blending proportions, mass ratio of dioctyl phthalate(DOP)and nano-silica on the mechanical properties of blends and its resistance to reagent, resistance to thermal distortion, structure morphology were investigated. The results showed that blends had better mechanical properties, better resistance to reagent and resistance to thermal distortion properties; nano-silica tougthening [NR-g-(GMA-co-St)]/PVC made compatibility and interfacial interaction between [NR-g-(GMA-co-St)] and PVC improving greatly ,The destruction of blends was PVC matrix deformation instead of dispersion particles pulling out from the blending matrix.The thermodynamics mechanism of blowing agents were studied by DSC and its decomposing properties had been evaluated. according to the analysis for decomposing mechanism of blowing agents, a compound blowing agent A was prepared. [NR-g-(GMA-co-St)]/PVC foam materials were prepared by means of chemical cross-linking and compression molding. Effect of blending proportions and mass ratio of DOP, blowing agents on properties of foam materials and its micro-structure, dynamical mechanical property were investigated. The results showed that, low Density, good rebound performance, closed-cells distributed uniformly foam materials were obtained when mass ratio of PVC was 30% , DOP was 30% , blowing agent A was 8% respectively. under Tg , storage modulus(E') decreased with mass ratio of blowing agent increasing. E'had a large decrease when the mass ratio of compound blowing agent A was 12%. the tanδincreased with A increasing at the same temperature, tanδgot the maximum when A was 8%, after that, the tanδdecreased.