Study On Preparation And Performance Of PVC-PANI Blends

Poly (vinyl chloride)(PVC) is one kind of general purpose polymer materials with mature production technology, low price and the overall excellent performance. It can be widely used in construction, transportation, packaging, electronic, electric appliance and automobile, etc. However, the surface resistivity of PVC materials is high to1014～1017Ω. For its good electrical insulation performance, in some cases, it is easy to produce static electronic and cause vacuuming, shock and other bad phenomenon. To a certain degree, the accumulated electrostatic still can produce a series of harm, cause great loss. And the complex antistatic PVC materials which can be got by blending, filling and compounding with the other materials, can be easy shaped. They are economic, suitable for mass industrialized production, and have great market potential and broad prospect of application.This article through the in-situ polymerization of aniline in micro foaming PVC, get the PVC/polyaniline (PANI) blend materials successfully, and realize the anti-static modification of PVC. This paper has studied the micro-foaming of PVC systemly; The effect of doping acid concentration, the type and concentration of oxidant on the conductance of PVC-PANI; and the influence of the mixing ratio of PVC-PANI powder in the PVC powder on the antistatic and mechanical properties of the composite materials. The main results are as follows:1. Make sure the best conditions of PVC foaming:Porous polyvinyl chloride (PVC) particles (20g) were swelled by compound solvent (10ml) with foaming agent2,2-azo-bis-iso-but-yronitrile (AIBN). When the volume ratio of cyclohexanone, acetone, butanone in compound solvent is1.7:6.3:2, and heated at112℃for8min, can get ideal result, the aniline adsorption rate(wt%) of micro-porous PVC is the best.2. Determine the optimum conditions of synthesising the PVC-PANI blend powder: Make sure the optimal concentration of (NH4)2S2O8is0.4mol/L; Determine the optimal concentration of dodecylbenzen-esulfonic acid is1.0mol/L; in the reaction condition of2h, can get the composite conductive powder of76.9S·m-1electrical conductivity.3. By the FT-IR spectra of PVC-PANI blend powder which is got by using foamed PVC as templates, the characteristic peaks of C-Cl in695cm-1and617cm"1becomes weeker,it means the obvious lost of C-Cl;we can find the characteristic peaks of adjacent replaced benzene in1800cm-1, it should be the reaction result of PVC with polyaniline or dodecylbenzenesulfonic acid; we still find N-H telescopic peak of sulfonic acid salt in1057cm"1place, it means that the polyaniline is good doped by dodecylbenzenesulfonic acid. Through the element analysis and FT-IR methods we research the mechanism of the doped polyaniline and conjecture the microscopic structure of PVC-PANI which is surface mosaic coated and internal local crosslinking.4. The seepage threshold of PVC-PANI blend materials:When the wt%of polyaniline from2.0%to3.3%, the resistivity of blend material has dropped sharply:from109Ω·cm to106Ω·cm, achieve the requirement of antistatic materials.