Cross-polymerized poly

Figure 13 Typical swelling and deswelling rates of cross-linked poly(acryloyl pyrroli-dine-co-styrene) between 27°C and 37°C. AS15 ( ) AS20 (A). The numbers indicate the content of styrene in the feed composition in moles during polymerization. Membrane thickness is 0.5 mm in the dried state. (From Ref. 34.)...

Figure 64 Hydrosilation reactions between l,7-bis(vinyltetramethyldisiloxyl)-m-carborane monomer and the polymeric cross-linker, poly(methylhydrosiloxane), producing hard, colorless networked plastics. (Adapted from ref. 133.)...

Graft polymerization of monomers such as acrylic acid on core particles consisting of magnetic iron oxide embedded in cross-linked poly (vinyl alcohol) (PVA) has been described previously (2). 

Andrews76 gave results of the work of Reed and Martin on cis-polyisoprene specimens crystallized from a strained cross linked melt and on solid state polymerized poly-oxymethylene respectively, explaining the results by simple two phase models. He also summarized the studies of Patel and Philips775 on spherulitic polyethylene which showed that the Young s modulus increased as a function of crystallite radius by a factor of 3 up to a radius of about 13 n and then decreased on further increasing spherulite size. 

In another approach, a fluorescent conjugated polymer was used as the material for the preparation of a chemosensor to detect 2,4,6-trinitrotoluene (TNT) and its related nitroaromatic compounds. To this end, microparticles, made of three-dimensionally cross-linked poly(l,4-phenylene vinylene) (PPV) via emulsion polymerization, were synthesized [61]. This material was chosen due to its high fluorescence intensity and sensitivity to changes in its microenvironment. The chemosensor was exposed to vapour containing different amounts of TNT and quenching of the polymer luminescence at 560 nm was observed after excitation at 430 nm. The dependence of the fluorescence signal in response to the analyte was described by a modified Stem-Volmer equation that assumes the existence of two different cavity types. The authors proposed the modified Stem-Volmer equation as follows ... 

The pyrolysis of poly[(germylene)diacetylenes] 35 under argon was studied112. At relatively low temperatures (150-250 °C) cross polymerization through the triple bonds was observed and further heating to temperatures up to 1200 °C provided crystalline... 

Chiral poly(meth)acrylamides as CSPs. In 1974, Blaschke reported the preparation and application of soft cross-linked poly(meth)acrylamide polymeric beads (11), which were synthesized by suspension polymerization from acryl or methacrylamides with chirality residing in the side chain of the amine component. Mechanically more stable chiral sorbents have subsequently been produced by polymerizing and covalently anchoring the monomers onto the surface of silica gels [ 192). The CSP obtained by this procedure from A -acryloyl-(S)-phenylalanine ethyl ester as monomer is commercialized by Merck under the tradename ChiraSpher. 

In 1971, Sheppard proposed that peptide synthesis would proceed more efficiently if the polymeric support was designed to have solvation properties similar to those of the peptide product.This line of reasoning led to the development of polyamide resins.The most successful of this type of support is based on cross-linked poly(dimethylacrylamide) (Pep-syn). Polyamide resins swell up to 10 times their dry volume in dimethylformamide and even more in water. On the other hand, they swell much less in dichloromethane. The few comparative studies that have been carried out between polystyrene and polyamide resins indicate that both give very similar results in routine solid-phase peptide synthesis. 

The structure analyses of two special types of dlacetylene "monomers," dlyne dimers and polydiyne macromonomers, are reviewed and preliminary results on the conversion and chromic behavior of one specific system, poly(l,8-nonadlyne) (F18N) are presented. Structure analyses of these materials before and after solid state polymerization allows a qualitative understanding of the dlacetylene polymerization. Cross-polymerized P18N has been shown to display solvatochromlc and thermochromlc behavior, even though this material Is Insoluble and Infusible. Examination of Initial optical spectroscopic data of the chromic behavior as a function of conversion, as well as consideration of the chromic behavior of conventional diacetylenes, leads to a possible explanation of the chromic behavior of crosspolymerlzed P18N. 

BMA and EGDMA monomers and UV-initiated polymerization to generate a cross-linked poly(methacrylate) network in the POPC bilayer. The substrate, ampicillin, diffused into liposomes through the OmpF channels and was converted to ampi-cillinoic acid. Thus a polymer-stabilized, vesicle-sized bioreactor with selective permeability was created, allowing for retention of the enzyme and ingress/egress of substrate and product. 

The Jacobsen epoxidations have also been carried out with the manganese chelate being made in zeolites.100 No manganese leached out. These reactions have been somewhat slower and have often tended to give somewhat lower ee s. Polymeric versions of the Jacobsen catalyst have also been used, but have often given lower ee s.101 Use of a Jacobsen catalyst occluded in a cross-linked poly(dimethyl-... 

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