Study On Preparation Of A New Type Of Macromolecular Compatibilizer And Its Compatibilization Ability

The polarity of the polyolefine type macromolecules is generally weak,whilestarch, a macromolecular material that usually composed of chain and branch shapemacromolecules, has a strong polarity. At the molecular level, the two kinds of materialsare incompatible, directly blending of them often results in major degradation in theblend's physical properties. To solve this problem, compatibilizer is needed to be addedinto the system in order to improve the compatibility.This thesis aims to prepare some kind of compatibilizer with the ability ofimproving the interphase compatibility in the blending of the macromolecules withdifferent polarities. The difference between this kind of compatibilizer and others is thata prepolymerization step is added in the preparation of the compatibilizer, in order toincrease the grafting active sites and improve the compatibilizing abilities. Thisexperiment takes the blend of starch and polyethylene and blend of starch andpolystyrene as the examples. The prepolymer of maleic anhydride and methylmethacrylate and the prepolymer of acrylic acid and methyl methacrylate are firstlyprepared, and the obtained prepolymers are qualitatively and quantitatively analyzed byIR spectroscopy and gas chromatography. Then the two kinds of prepolymers areblended with polyethylene and polystyrene in certain proportions respectively, theobtained blends are the required compatibilizers. The obtained two kinds ofcompatibilizers are added into the blending of starch and polyethylene and blending ofstarch and polystyrene in certain proportions respectively, and extruded through thesingle screw extruder, the extruded products then analyzed and detected by scanningelectron microscope, thermal analyzer and two kinds of mechanical property testers.The result shows that the performance of the starch/polyolefine blends that addedwith the obtained compatibilizers is better than those not added, the compatibilizingperformance of the maleic anhydride type compatibilizers is relatively better than theacrylic acid type compatibilizers. Hence the route of compatibilizing the polymer blendsthat having different polarities by prepolymer type compatibilizers is to be provedpositivity good. There lies small difference between different prepolymer typecompatibilizers in compatibilizing performance. All of these also point out a new routeto preparing the new type reactive macromolecule compatibilizers.