Study On Synthesis And Properties Of Linear Amino-Polystyrene

Functional polymer has a wide range of applications. Amino-polystyrene which can be protonated with its amino, can be widely used in biomedical polymers, polymer-support catalyst and water treatment and many other fields.In this dissertation, amino-polystyrene was prepared by three synthesis routes, respectively.(1) Poly(p-nitrostyrene) (PPNS) was prepared by nitration of linear PS using the mixture of nitric acid and sulfuric acid as nitrating agents, and finally PPNS was reduced to poly(p-aminostyrene) (PPAS). The resultant polymers were characterized by means of Fourier transform infrared spectrometer (FT-IR), nuclear magnetic resonance (NMR) spectrometer, thermogravimetric analyzer (TGA) and differential scanning calorimeter (DSC), respectively. The effects of reaction temperature, reaction time and mixed acid composition on nitration and the kind and amount of reducing agent on reduction were studied. The results show that the nitro groups are incorporated into benzene rings of PS and PPNS is reduced to PPAS. Both PPNS and PPAS have two decomposing stages. The thermal stability of PS, PPNS and PPAS rank in descending order. The glass transition temperature (Tg) of PPNS increased with increasing rate of nitration, and the Tg of PPAS is also high. The rate of nitration increased with increasing reaction temperature, reaction time and volume of sulfuric acid in acid mixture. With reducing the molecular weight of PS and increasing the amount of reducing agent, the water solubility of PPAS increased.(2) The linear poly(p-chloroacetyl styrene)(PS-Acyl-Cl) was prepared by Friedel-Crafts acetylation of linear PS using chloroacetyl chloride and aluminium trichloride as chloroacetylation reagent and catalyst, respectively. Then PS-Acyl-Cl was aminated to poly(p-(a-amin o-ethylamino)acetyl styrene)(PS-Acyl-EDA) using ethylene diamine (EDA) as aminating agent. The resultant polymers were characterized by FT-IR, TGA and DSC. The effects of reaction conditions on chloroacetylation and amination were studied. The results show that chloroacetyl groups are introduced into benzene rings of PS and the amination is successful. Both PS-Acyl-Cl and PS-Acyl-EDA have two decomposing stages. And the thermal stability of PS-Acyl-Cl decreased and Tg of PS-Acyl-Cl increased with increasing substitution value of chloroacetyl groups.(3) 1,4-Bis(chloromethoxy)butane was synthesized using 1,4-butanediol, formaldehyde and phosphorus trichloride as raw material. The poly(p-chloromethyl styrene)(PS-Meyl-Cl) was performed using 1,4-Bis(chloromethoxy)butane and Lewis acid as the chloromethylation reagent and catalyst, respectively. Then PS-Meyl-Cl was aminated to poly(p-(amio-e thylamino)methyl styrene) (PS-Meyl-EDA) using EDA as aminating agent. The resultant polymers were characterized by FT-IR and TGA. The effects of reaction conditions on chloromethylation and amination were studied. The results show that the chloromethyl groups are intrduced into benzene rings of PS and the amination is successful. Both PS-Meyl-Cl and PS-Meyl-EDA have two decomposing stages. And the thermal stability of PS-Meyl-Cl decreased with increasing substitution value of chloromethyl groups. Considering various factors, the optimum reaction conditions for chloromethylation are determined.