The Synthesis Of The Long-chain Polystyrene With Functional End Groups And Its Compound With Functionalized Polypropylene

In this dissertation, the polystyrene with a controllable molecular weight and narrow distribution of molecular weight as well as double end group was synthesized using ATRP reaction. The optimum reaction condition was obtained by discussing in detail influence of various factors on poly-reaction and further, polystyrene with different relative molecular weight was synthesized under such optimum condition. From the aspect of the feature and mechanism, it is proven that this reaction can be ascribed to the typical ATRP reaction by GPC and reaction dynamics analysis. Further, it also can be concluded that end-carboxyl and end Br group exist.By means of end-group transfer-reaction, the end-carboxyl was transformed into end-amidogen, which was investigated based on FTIR.PP-g-MAH with graft-ratio of 2.67% was obtained in terms of suspend polymerization, under an optimum reaction condition which was determined after a discussion in detail on the relationship between different factor and reaction. PP-g-PS was also synthesized by reaction between end amino group on PS and acid anhydride on PP and also, FTIR and DSC were employed to describe the structure of the graft copolymer.The crystallization behavior of PP and PP-g-PS was studied by polarized light microscopy, X-ray diffraction (XRD) and DSC. The result show that the crystallization behavior of PP and PP-g-PS are quite different and the crystal habit and the degree of crystallization are changed after the PS chain grafted on PP. Anther phenomenon was observed that the crystallographic form of PP was transformed fromαtoβ.The rheometer was employed in the linear viscoelasticity behavior study of PP and PP-g-PS and the result show that complex viscosity of PP-g-PS at the same temperature are quite higher than PP. This phenomenon indicate that very litter PS chain grafting on PP can bring huge change of the structure of PP and this change is reflected by the increase of viscosity.According to Time–temperature superposition principle the PP-g-PS can be proved to be homogeneous phase structure by different temperatures dynamic frequency scanning curves and this result can be proved by the SEM image.