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-alpha,alpha '-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 H-1 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.