ResumoCopolímeros reticulados à base de divinilbenzeno vêm sendo extensivamente empregados como suportes de catalisadores e complexantes de íons metálicos, adsorventes de compostos orgânicos e fases estacionárias em separações cromatográficas. A introdução de grupos biocidas a estes materiais é relatada em patentes desde a década de 1970, contudo apenas a partir do ano 2000 estes copolímeros passaram a ser aplicados também como suportes para grupos biocidas. A presente revisão apresenta as principais combinações de suportes poliméricos e grupos biocidas estudados com o objetivo de preparar resinas biocidas reticuladas. Procura-se estabelecer relação entre as características dessas resinas e seu mecanismo de ação biocida.

AbstractCrosslinked copolymers of divinylbenzene have been extensively employed as supports for catalysts and chelating groups of metal ions, adsorbents of organic compounds and stationary phases for chromatography separations. The use of these copolymers as support for biocidal groups is reported in patents since the 1970s, but only after 2000 were these copolymers also applied as supports for biocidal groups. This paper describes the main combinations of polymeric supports and biocide groups employed in biocide polymer resins. The relationship between the characteristics of these resins and their mechanism of action is also established in this work.

Este artigo avalia o emprego de copolímeros porosos (a base de estireno-STY e vinilpiridina-VP, reticulados com divinilbenzeno-DVB) como adsorventes de 4-nitrofenol de soluções aquosas. Os copolímeros foram sintetizados através de polimerização em suspensão aquosa via radical livre na presença de heptano (HEP) e tolueno (TOL) em diferentes proporções como agentes porogênicos. As unidades de VP nos copolímeros foram modificadas quimicamente pela adição eletrofílica de monômeros vinílicos funcionalizados (acrilonitrila). Os copolímeros quaternizados foram caracterizados por espectrofotometria na região do infravermelho (FTIR), análise elementar (CHN), microscopia ótica (OM) e microscopia eletrônica de varredura (SEM).

This article aims to evaluate porous copolymers (based on styrene-STY and vinylpyridine-VP, cross-linked with divinylbenzene-DVB) as adsorbents for 4-nitrophenol from aqueous solution. These copolymers were synthesized by suspension polymerizations in the presence of heptane (HEP) and toluene (TOL) in different proportions as porogenic agents. The VP units of the copolymers were chemically modified by the addition of the electrophilic ethylenic compound (acrylonitrile). The quaternized copolymers were characterized by infrared spectrometry (FTIR), elemental analysis (CHN), optical microscopy (OM) and scanning electron microscopy (SEM).

This review deals with the homo- and copolymerization of styrene with nickel catalysts. The catalytic activity, polymer stereoregularity, polymer molecular weight and polydispersity are dependent upon nickel ligands and reaction parameters. Catalysts supported on silica, treated with methylaluminoxane (MAO), have shown higher stereospecificity and activity compared to homogeneous ones. The influence of these parameters is discussed focusing on the elucidation of some aspects of the polymerization mechanism.

The Ziegler-Natta catalyst and the polymerization thereof are systems which require careful handling and special treatment of chemicals. In spite of the use of inert atmosphere and dry chemicals, some Ziegler-Natta systems may present low activities or even may deactivate because of unsuitable handling. Some features of the TiCl3 synthesis and its characterization when related to the presence of impurities are described. Evidences of poor handling of chemicals and/or laboratory devices while in synthesis of the catalyst are emphasized. The problems arising from butadiene polymerization and some relevant details in propylene polymerization are also presented with teaching objectives.