Divinylbenzene anionic prepared polystyrene

TABLE 1. Physical properties of star polystyrenes prepared by the incremental addition of divinylbenzene to a polystyrene anion having a of ronghly 26,000 daltons. 

Hyperbranched polymers have also been prepared via living anionic polymerization. The reaction of poly(4-methylstyrene)-fo-polystyrene lithium with a small amount of divinylbenzene, afforded a star-block copolymer with 4-methylstyrene units in the periphery [200]. The methyl groups were subsequently metalated with s-butyllithium/tetramethylethylenediamine. The produced anions initiated the polymerization of a-methylstyrene (Scheme 109). From the radius of gyration to hydrodynamic radius ratio (0.96-1.1) it was concluded that the second generation polymers behaved like soft spheres. 

A nine armed star block copolymer of styrene and isoprene with a polystyrene content of 27% has been prepared by Fetters204 via a two-stage anionic polymerization using m-divinylbenzene as coupling agent and studied by electron microscopy. Spheres of polystyrene arranged in a body centered cubic lattice have been claimed for this copolymer204. ... 

The resins are prepared first by copolymerizing styrene (ST) and divinylbenzene (DVB), resulting in a cross-linked polystyrene. Usually, they are produced in the form of spherical beads. These beads are sulfonated with sulfuric acid for anionic resins and methylated with chloromethyl ether followed by quatemization with trimethylamine for cationic resins. Two types of resins exist gel and microporous. The microporous beads are used to remove ionic substances quickly while the gel-type beads are used for sustaining drug release over a long period of time. 

M. Negre, M. Bartholin and A. Guyot, Autocross-linked isoporous polystyrene resins, Angew. Makromol. Chem., 1979, 80, 19-30 J. Hradil and E. Kralova, Styrene-divinylbenzene copolymers post-cross-linked with tetrachloromethane, Polym., 1998, 39, 6041-6048 S. Belfer and R. Glozman, Anion exchange resins prepared from polystyrene cross-linked via a Friedel-Craft reaction, J. Appl. Polym. Sci., 1979, 24, 2147-2157. 

For preparation of the novel type of SIRs, two types of resins were proposed (1) divinylbenzene (DVB)-cross-linked polyvinylpyridine resins, and (2) conventional anion exchange resins with cross-linked polystyrene skeleton bearing strong basic quaternary amine or weak basic tertiary amine groups. Their properties are summarized in Table 9.2. 

---