Chemical transformation of insoluble copolymers of styrene

Abstract

With the objective of synthesizing various insoluble polyelectrolytes and complexes, the chemical reactions of insoluble styrene copolymers (styrene–divinylbenzene or styrene–diallyl maleate) and of copolymers which become insoluble during the synthesis (styrene–butadiene) were studied. By substituting the chlorine atom in chloromethylated copolymers for ionic and complexogenic groups new polymer ion exchangers and complexes have been obtained. Chloromethylation of the copolymers was accomplished with the aid of paraformaldehyde and hydrogen chloride in the presence of zinc chloride in dichloroethane (copolymer I). The extent of conversion is determined by the structure and swelling capacity of the polymer and varies between 65 and 95%. The chlorine atom of copolymer I is completely replaced by an amino group under the action of triethanolamine (copolymer II). The polyelectrolytes formed possess the properties of quaternary ammonium bases with basicity 2.6–2.9 meq./g. The high swelling capacity of copolymer II has been utilized for investigating the possibility of polymerizing vinyl derivatives in the copolymer network. The polymerization of α‐methylvinylpyridine in copolymer II granules leads to a polymer‐in‐copolymer system containing up to 30% polymer and incapable of separation by extraction. The basicity of such a system attains a value of 5.1 meq./g. The replacement of chlorine in copolymer I by phosphine or sulfides gave new insoluble polymer of the phosphonium (copolymer III) or sulfonium (copolymer IV) type. A comparative study has been made of the properties of the ammonium, phosphonium, and sulfonium salts. From copolymer II insoluble complexes containing an aminotriacetic or aminodiacetic acid group or a β′, β″, β‴‐triaminotriethylamine group have been obtained. The instability constants of the Ni++, Cu++, Ca++, and Zn++ complexes with the insoluble polymeric complexes have been determined.

Resinas poliméricas para separação e pré-concentração de chumbo

“…A caracterização da área específica e da distribuição de diâmetros de poro é de grande necessidade para se avaliar o balanço entre área específica e diâmetro de poro altos, dois parâmetros necessários à obtenção de suportes com boa capacidade de retenção e velocidade de difusão, porém antagônicos [103][104][105][106] . Quanto à velocidade de extração de espécies iônicas a partir de uma solução aquosa, esta será função da própria velocidade de reação entre o grupo funcional e o íon e, também, da facilidade de acesso aos sítios ativos do suporte, que será favorecido se o suporte apresentar poros largos.…”

Review of laboratory methods for the preparation of polymer films

“…Membranes for desalination of water have been developed since Loeb and Sourirajan's work, in 1960 (39)(40)(41)(42)(43)(44)(45)(46). Ion-exchange membranes are also of great interest (47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59). Biological research is another important field of membrane application (2, [60][61][62][63][64][65][66][67].…”