Wen-Xing Chen

Synthesis, copolymer composition, and rheological behavior of functionalized polystyrene with isocyanate and amine side groups

Isocyanate and amine functionalized polystyrene (PS) were prepared through the solution copolymerization method with the presence of the intermediate substance 3-isopropenyl-α,α′-dimethylbenzene isocyanate (TMI). The samples with different copolymer composition of functional group were prepared with a range of molecular weights by free radical polymerization, the functional group such as isocyanate, acid amine, and amine group were introduced by appreciate reaction conditions. The isocyanate, acid amine, and amine functionalized polystyrene (PS), denoted as P(St-co-TMI), intermediate product P(St-co-TMITBC) and PS-NH2, respectively. The chemical structure of the samples was characterized by Fourier transform infrared spectroscopy (FT-IR) and 1H NMR spectroscopies. The results indicated that the functional groups successfully formed on the side chain of polystyrene. The molecular weight, its distribution, and copolymer composition of functional group were analyzed by gel permeation chromatography combined with FT-IR. The results showed that the copolymer composition increased with the increasing functional monomer content. Viscoelastic behavior in the melt state was investigated and analyzed with dynamic rheology to determine the influence of the interaction of the polymer chain special groups on the rheological properties.

An Investigation and Comparison of the Blending of LDPE and PP with Different Intrinsic Viscosities of PET

The blending of aliphatic polyolefins and aromatic poly(ethylene terephthalate) (PET) based on different intrinsic viscosities (IV) was conducted in a torque rheometer. The comparison of blend components in terms of low density polythene (LDPE) and polypropylene (PP) in blending with PET was investigated, and the effects of the IV and proportion of PET on polymer blends are discussed in detail. Polymer blends with or without compatibilizer were examined by using a differential scanning calorimeter, thermogravimetric analyzer, rotary rheometer, field-emission scanning electron microscopy and a universal testing machine. It was found that the blending led to an increase in processability and a decrease in thermal stability for blends. The morphological analysis revealed that the incompatibility of blends was aggravated by a higher IV of PET, while this situation could be improved by the addition of compatibilizer. Results showed that there was an opposite effect for the tensile strength and the elongation at break of the polymer blend in the presence of a compatibilizer, wherein the influence of IV of PET was complicated.