Polystyrene side graft

Molecular Weight of Grafted Side Chains. In previous work the wool had been hydrolyzed away from the grafted material in order to isolate the polystyrene side chains. Sodium hydroxide was used with good results however, about one-half of the polystyrene was soluble in only such solvents as dimethyl formamide and benzene-methanol mixtures. Infrared examination showed the presence of groupings charac-... 

So far, there have been only few reports about the synthesis of amphipolar polymer brushes, i.e. with amphiphilic block copolymer side chains. Gna-nou et al. [115] first reported the ROMP of norbornenoyl-endfunctionalized polystyrene-f -poly(ethylene oxide) macromonomers. Due to the low degree of polymerization, the polymacromonomer adopted a star-like rather than a cylindrical shape. Schmidt et al. [123] synthesized amphipolar cylindrical brushes with poly(2-vinylpyridine)-block-polystyrene side chains via radical polymerization of the corresponding block macromonomer. A similar polymer brush with poly(a-methylstyrene)-Wocfc-poly(2-vinylpyridine) side chains was also synthesized by Ishizu et al. via radical polymerization [124]. Using the grafting from approach, Muller et al. [121, 125] synthesized... 

Direction substitution of element notation (Equation 10) representing the grafting of polystyrene side chains onto polybutadiene backbone. An AB-crosslinked copolymer of Bamford and Eastmond (14a)... 

In the completed study, exact amounts of the powdered materials were sprinkled onto the wood-resin surface. Analysis of the test specimens revealed that under the press times and temperatures used the phase transition of the polystyrene side chains on the graft polymer was not efficient. Further, in order for the graft polymer to be effective as a interfacial agent, it must locate preferentially at the blend interface (SI), The research team hopes to develop procedures in the future to allow the polystyrene and graft polymers to be dissolved in an organic solvent for application to the wood resin surface. This should allow the graft polymer to locate at the blend interface and improve bonding efficiency. 

A blend was prepared by dissolving a rubber material in styrene and polymerizing the system. The blend contains not only rubber and polystyrene (PS), but also a graft polymer because of the attachment of short polystyrene side chains to the rubber molecules. The toughness of this material was markedly improved compared to that of the unmodified PS. A technology based on bulk polymerization [26] has been widely used the concentrated emulsion polymerization method employed by us, however, allows one to obtain rubber toughened latexes. 

While formulations with rubber compounded into the GPPS are effective, grafting the elastomer into the continuous phase is preferred. Commercial polymerization processes produce a polymer system that not only has an elastomer incorporated, but also a grafted species where short polystyrene side chains have been attached to the rubber domains. This grafting anchors... 

The method of mixing the polystyrene and rubber has a profound effect on the properties of the product. Thus, much better results are obtained if the material is prepared by polymerization of styrene in the presence of t he rubber rather than by simply blending the two polymers. The product of the former method contains not only polystyrene and straight rubber but also a graft copolymer in which polystyrene side chains are attached to the rubber. 

Some of the membranes considered as alternatives to Nafion contain aromatic building blocks, in particular sulfonated phenyl groups or grafted polystyrene side chains. For this reason, toluene sulfonic acid was chosen as a model compound to investigate its reactions with HO radicals as a function of pH. The HO radicals were generated by... 

This chapter focuses on the latest efforts in our laboratory aimed at the synthesis and the physical characterization of arborescent polymers. The synthesis of arborescent styrene and isoprene homopolymers is discussed, together with copolymers incorporating a polystyrene substrate grafted with side chains of different compositions such as poly(2-vinylpyridine). 

Figure 1 Self-assembly of polystyrene-tethered gold NRs in nanopolymers in selective solvent, (a) Schematic of the monomer building block an amphiphilic gold NR carrying a double layer of CTAB along the longitudinal side (the 100 facet) and polystyrene molecules grafted to both ends, (b) SEM image of the nanopolymer self-assembled in the DMF/water mixture at water content of 20 wt.%. The scale bar is 100 nm. The insets show a corresponding schematic of the NR assembly. Reproduced with permission from Nie, Z. H. Fava, D. Kumacheva, E. etal. Nat. Mater. 2007, 6,609-614. ...

In 2007, Holdcroft and coworkers presented polythiophene-based mainside chains in which fuUerene moieties were grafted (Scheme 2.10) [30]. 

Today the common practice is first to dissolve the rubber in the styrene monomer and then to polymerise the styrene in the usual way. By this process the resultant blend will contain not only rubber and polystyrene but also a graft polymer where short styrene side chains have been attached to the rubber molecules. This gives a marked improvement in the impact strengths that can be obtained. 

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