Methacrylate-PDMS

Abbreviations l-PLA, poly-L-lactic acid PGA, poly-glycolic acid d-PLA, poly-D-lactic acid PMMA, poly-methyl methacrylate PEMA, poly-ethyl methacrylate PDMS, poly(dimethyl-siloxane) PEHA, poly(2-ethylhexyl acrylate). ... 

NR natural rubber PS polystyrene PEO poly(ethylene oxide) PHPMA poly(hydroxi-ethyl-methacrylate) PDMS polydi-methylsiloxane PVAC poly(vinyl acetate) PAA poly(acryamide) PVA poly(vinyl alcohol) r correlation coefficient. 

Luo et al. [6] used a polydimethylsiloxane macro-initiator to initiate polymerization of methacrylate monomers with fluorinated side groups to prepare fluorosilicone polymers. To obtain diblock copolymers with a low surface energy, they designed poly(dimethylsiloxane)-block-poly(2,2,3,3,4,4,4-heptafluorobutyl methacrylate) (PDMS-1 -PHFBMA) diblock copolymers by atom transfer radical polymerization (ATRP) technique. To initiate 2,2,3,3,4,4, 4-heptafluorobutyl methacrylate polymerization, bromine end-capped polydimethylsiloxane (PDMS-Br) was used as the macro-initiator. Scheme 6.5 shows a schematic representation of the PDMS-fc-PHFBMA diblock copolymers. The system was strictly deoxygenated... 

Well-defined poly(dimethylsiloxane)-block-poly (methyl methacrylate)-block-poly(2,2,3,3,4,4,4-heptafluorobutyl methacrylate) (PDMS-( -PMMA-( -PHFBMA) triblock copolymers were synthesized by Lian et al. via ATRP, and their microstructures were investigated using atomic force microscopy (AFM) [56]. 

J. J. Falcetta, G. D. Friends, G. C. C. Niu, Solid Article Formed from a Polymer Network with Simultaneous Interpenetration, Fr. Demande 2365606 (1978). Moldings, containing interpenetrating networks of crosslinked hydrophobic siloxane chains, as contact lenses. SINs of hydroxy ethyl methacrylate/PDMS. Soft contact lenses. 

Abbreviations PMMA, poly(methyl methacrylate) PDMS, poly(dimethyl siloxane) PS, polystyrene PCLP, polychloroprene PE, polyethylene PnBM, poly(w-butyl methacrylate) PVA, poly(vinyl acetate) PB, polybutadiene. 

Figure 7.20 Relaxation time spectra H(ln t) for poly-n-dodecyl methacrylate (PDM), poly-n-octyl methacrylate (POM), poly-n-hexyl methacrylate (PHM), poly-n-butyl methacrylate (PBM), polyethyl methacrylate (PEM). Dashed lines are a slope of—j predicted by the Rouse theory. (Adapted from Ferry, j.D. (1980) Viscoelastic Properties of Polymers, 3rd edn, John Wiley Sons, New York, Ch. 11. Copyright (I960) John Wiley Sons, Inc.)...

ABA type poly(hydroxyethyl methacrylate) (HEMA) and PDMS copolymers were synthesized by the coupling reactions of preformed a,co-isocyanate terminated PDMS oligomers and amine-terminated HEMA macromonomers312). Polymerization reactions were conducted in DMF solution at 0 °C. Products were purified by precipitation in diethyl ether to remove unreacted PDMS oligomers. After dissolving in DMF/toluene mixture, copolymers were reprecipitated in methanol/water mixture to remove unreacted HEMA oligomers. Microphase separated structures were observed under transmission electron microscope, using osmium tetroxide stained thin copolymer films. 

Yamashita and co-workers have also determined the reactivity ratios of styryl terminated PDMS macromonomers (M,) with styrene (M2) and methyl methacrylate (M2)123>. They have determined (r2) and (r2) as 1.1 and 0.60 respectively. These values... 

MA and St denotes methacrylate and styrene terminated PDMS Macromonomers respectively ... 

Using these macroinitiators PDMS-polystyrene and PDMS-poly(methyl methacrylate) multiblock copolymers were synthesized 305). Due to the backbone Structure of these macroinitiators and their thermolysis mechanisms, the copolymers obtained... 

Siloxane containing interpenetrating networks (IPN) have also been synthesized and some properties were reported 59,354 356>. However, they have not received much attention. Preparation and characterization of IPNs based on PDMS-polystyrene 354), PDMS-poly(methyl methacrylate) 354), polysiloxane-epoxy systems 355) and PDMS-polyurethane 356) were described. These materials all displayed two-phase morphologies, but only minor improvements were obtained over the physical and mechanical properties of the parent materials. This may be due to the difficulties encountered in controlling the structure and morphology of these IPN systems. Siloxane modified polyamide, polyester, polyolefin and various polyurethane based IPN materials are commercially available 59). Incorporation of siloxanes into these systems was reported to increase the hydrolytic stability, surface release, electrical properties of the base polymers and also to reduce the surface wear and friction due to the lubricating action of PDMS chains 59). 

Polystyrene-PDMS block copolymers4l2), and poly(n-butyl methacrylate-acrylic acid)-PDMS graft copolymers 308) have been used as pressure sensitive adhesives. Hot melt adhesives based on polycarbonate-PDMS segmented copolymers 413) showed very good adhesion to substrates with low surface energies without the need for surface preparation, such as etching. 

Polymerization of methyl methacrylate in supercritical carbon dioxide with PDMS based stabilizers A study on the effect of stabilizer anchor groups... 

Much work on the preparation of nonaqueous polymer dispersions has involved the radical polymerization of acrylic monomers in the presence of copolymers having the A block the same as the acrylic polymer in the particle core 2). The preparation of polymer dispersions other than polystyrene in the presence of a PS-PDMS diblock copolymer is of interest because effective anchoring of the copolymer may be influenced by the degree of compatibility between the PS anchor block and the polymer molecules in the particle core. The present paper describes the interpretation of experimental studies performed with the aim of determining the mode of anchoring of PS blocks to polystyrene, poly(methyl methacrylate), and poly(vinyl acetate) (PVA) particles. 

For (a), hydroxypropyl cellulose (HPC) (6-8), poly(vinyl pyrrolidone) (PVP) (9,10), poly(acrylic acid) (PAA) (9), and poly(dimethyl siloxane) (PDMS) (11) are usually employed. Ober et al. reported that the copolymers of isobutylene/isoprene and various methacrylates, which have weak polarity, are appropriate stabilizers for... 

For (b), a block copolymer, in which one side of the block has affinity to the solvent and the other block to the polymer particle, is the most reasonable stabilizer. Block copolymers of polystyrene/halogenated polybutadiene, polystyrene/ polyethyleneglycol, and polystyrene/PDMS are examples of this type of stabilizer (12). When using a block copolymer, it is possible to provide appropriate amphiphilic and other surface properties by changing the block ratio. For example, when using a block copolymer of polystyrene/PDMS for polymerization of methyl methacrylate in hexane, the ratio of polystyrene/polydimehtylsiloxane should be below 4.4 (13). If the ratio is above 4.4, the block copolymer forms a stable micelle and will not function properly as a stabilizer. 

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