Research On Toughenness And Property Of Poly(vinyl Choloride)

PVC is one of the first industrilized plastics, a prevailing plasticswith large production. Among PVC moleculars there are lots ofcholorine atoms, which make the polymer more polarity and rigidity,besides, PVC is good in anti-erosion, insulation and processing, so,it has been widely used.But, PVC has such serious defect, as had thermal stability,rigorious hard property which can be wiped off by some measures ofmodification. Therefore, this thesis has explored some research asfollowing:1 The blend of PVC and copolymer SBSPVC/SBS films were made by solution cast method, both thefeature and strength capability were also studied, meanwhile, thecompatibility of EVA in the system was analyzed. It was found thatwithin some content area of PVC/SBS EVA could increase themiscibility of PVC and SBS, enhance material strain. The relativeviscosity of solution was measured, phase inversion content wasfound, too.A series of sulphonated SBS were achieved by reacting SBS blockcopolymer with sulphuric acid, meanwhile, the blends of PVC andsulphonated SBS were studied. By means of strength capabilityexamination and DSC analysis, it was found the miscibility wasincreased after SBS was sulphonated.2 The chemical grafting of styrene and PVC membrane2.1 The reaction condition of graftingBy means of the swelling and seepage of Styrene (St) to PVC film,St was grafted onto PVC film by the initiation of BPO .The effects ofreaction temperature, reaction time, BPO and St concentrations,Oxygen on grafting ratio were studied. The grafted films werecharacterized by FT-IR and DSC. The results showed that the bestreaction condition was achieved when the reaction temperature was80'C, reaction time was 7.5h, BPO concentration was 0.03mol/l;composition ratio of St to PVC film was 450 with oxygen avoided.Meanwhile, the thermal stability of PS-g-PVC film was enhanced.2.2 Thermal stability of St/PVC grafting filmBy means of the radical suspension Polymerization, St/PVC graftingFilm was made. all the films were analyzed by UV-vis spectrum, IRspectrum and TGA. It was found the thermal stability of St/PVC filmwas improved. Meanwhile, thermal stability mechanism was studied.3 UV-surface grafting of PVC3.l Study on the grafting of MMA and PVC films by UVBy means of liquid phrase grafting method, a series of MMA/PVCgrafting films were prepared by UV. Initiator concentration, monomerconc9ntration, radiation time, light strength were studied. Wheninitiator concentration was 6. 5 X l 0-'mol/l, monomer concentrationwas 2.0mol/l,radiation time was 2.0 hours, and light strength wasstronger, grafting ratio was excellent. The structure of the graftingfilms was proved by FT-IR spectrum, finally, TGA of the grafting filmsshowed thermal stability of PVC films modified by MMA wasenhanced.3.2 Study on the grafting of B --HYDROPROPYLACRYLATE and PVC'films by UVBy means of liquid phrase grafting method, a series of B－Hydropropylacrylate(8－IIP)／PVC graftlllg films were prepared by UV．Inltlator concentration,monomer concentration,radiation time, light strength were studied．When Inltlator concentration was 6．siX 103mol／l,monomer concentration was 2．omol／l,radlatlontlme was 2．0 hours,and light strength was stronger,grafting ratio was excellent．The structure of＊theure grafting films was proved by FT－IR spectrum,hnally TGAofthe grafting nlms showedthermal stabilityofPVC films modifiedby0－HPATATwas enhanced.