Radiation-grafted polystyrene

Applications of radiation grafting in the coating industry for improving adhesion and other properties has been an active field. For instance, grafting of styrene onto polyester fibers was found to improve the interfa-cial adhesion between grafted chopped polyester fibers and polystyrene used as a matrix [139]. 

Our library synthesis was carried out with a set of 27 tube-shaped solid phase synthesis support, called MicroTubes. These supports are prepared by radiation grafting of polystyrene ( — 350 pmol) onto polypropylene tubes, chemically functionalizing the polystyrene with aminomethyl groups to afford about 55 imol of amine per tube, inserting a reusable Rf ID tag into each tube, and heat-sealing the tube ends to prevent loss of the tag. The chemical conversion of all 36 aminomethyl tubes was carried out simultaneously using standard procedures with rink amide linker, each with —46 pmol of available amine per tube.1 2... 

The Acid Effect. The possible mechanistic role of hydrogen atoms in the current radiation grafting work becomes even more significant when acid is used as an additive to enhance the copolymerisation. At the concentrations utilised, acid should not affect essentially the physical properties of the system such as precipitation of the polystyrene grafted chains or the swelling of the polyethylene. Instead the acid effect may be attributed to the radiation chemical properties of the system. Thus Baxendale and Mellows (15) showed that the addition of acid to methanol increased G(H2) considerably. The precursors of this additional hydrogen were considered to be H atoms from thermalised electron capture reactions, typified in Equation 5. 

Biichi, F. N., Gupta, B., Haas, O. and Scherer, G. G. 1995. Study of radiation-grafted FEP-g-polystyrene membranes as polymer electrolytes in fuel cells. Electrochimica Acta 40 345-353. 

Fibrous anion exchangers were prepared from polypropylene staple fibres 22 mcm in diameter by radiation grafting of polystyrene followed by chloromethylation and amination of the grafted polymer. The grafting was... 

The mechanismsof the acid effect has been extensively investigated (12-15, 21) whereas the current use of the polyfunctional monomers as enhancement additives in grafting is novel. The role of acid in these radiation grafting reactions is complicated and there is evidence that a number of pathways contribute to the overall enhancement effect. Thus mineral acid, at the levels used, should not affect the physical properties of the system such as swelling of the trunk polymer or precipitation of the grafted polystyrene chains. Instead evidence (12) indicates that the acid effect is due to a radiolytic increase in G(H) yields in the monomer-solvent system due to reactions similar to those depicted in Equations 1 and 2 for styrene-methanol. 

Similar polymer compatibilization effects were observed by Wellons and co-workers (19) on radiation graft copolymers of cellulose acetate and polystyrene and by Riess and his colleagues (20) on various block copolymers. Hughes and Brown (21) also reported some evidence of compatibilization in a... 

The objective of this chapter is to review the latest progress in the preparation of radiation-grafted PEMs for fuel cells using EB. In particular, the results associated with the preparation and the properties of two types of membranes having polystyrene sulfonic acid (PSSA) grafted to poly(vinylidene fluoride) (PVDF) films are reviewed. The fundamentals of RIG operation with EB accelerators are also briefly reviewed to furnish a clear understanding of the mechanism of PEM formation and how membrane composition and, consequently, their properties can be controlled. 

Nasef, M.M., Zubir, N.A., Ismail, A.F. and Khayet, M. 2006c. Sulfonated radiation grafted polystyrene pore-filled poly(vinylidene fluoride) membranes for direct methanol fuel cell Structure-property correlations. 200 642-644. 

Nasef, M.M., Saidi, H. and Dahlan, K.Z.M. 2010b. Radiation grafted polyfvinylidene fluoride)-gra -polystyrene sulfonic acid membranes for fuel cells Structure-property relationships. Chin.. 1. Pohm. Sci. 28 761-770. 

S.D. Flint, R.C.T. Slade, Investigation of radiation-grafted PVDF-g-polystyrene- sulfonic-acid ion exchange membranes for use in hydrogen oxygen fuel cells. Solid State Ionics 97 (1-4) (1997)299-307. 

The pin consists of a radiation-grafted polypropylene crown fitted to an inert polypropylene stem . Graft polymers used with the Multipin system include polystyrene, a methacrylamide copolymer (38), and poly(hydroxyethyl methacrylate) (34) (HEMA). We have found that the HEMA surface is best suited to peptide synthesis. Historically, peptides were prepared in a non-cleavable format on the crown surface for epitope mapping applications (39). Over the past decade, however, most peptides prepared by the Multipin method have been synthesized on cleavable linkers. The linkers used for peptide synthesis are outlined below. 

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