Acrylates, fluorinated other applications

Other applications of FTIR in microstructural analysis of homopolymers include 1,4-diazophenylene - bridged Cu-phthalocyanine [63], isobornyl methacrylate [64], polypropylene [65, 66], polyaniline [67, 68], polycaprolactone [69], viscose fibres [70], Kevlar [71], polystyrene sulfonic acid [66, 72], syndiotactic polystyrene [73], isotactic polypropylene [66,74,75], polyurethane [76], PMMA [75, 77], poljmrethane ether [78], PE [79-80], fluorinated acrylates [81], rigid PU [82], N-(2-biphenyl)4-(2 phenylethynyljphthalamide [83], polyacrylic acid [84], polysodium styrene sulfonate [84], and polyacrylic acid [85]. 

Many other crosslinking reactions are used in commercial applications. A variety of halogen-containing elastomers are crosslinked by heating with a basic oxide (e.g., MgO or ZnO) and a primary diamine [Labana, 1986 Schmiegel, 1979]. This includes poly(epichlorohydrin) (Sec. 7-2b-6) various co- and terpolymers of fluorinated monomers such as vinylidene fluoride, hexafluoropropene, perfluoro(methyl vinyl ether), and tetrafluoroethylene (Sec. 6-8e) and terpolymers of alkyl acrylate, acrylonitrile, and 2-chloroethyl vinyl ether (Sec. 6-8e). 

Of a large number of possible fluorinated acrylates, the homopolymers and copolymers of fluoroalkyl acrylates and methacrylates are the most suitable for practical applications. They are used in the manufacture of plastic lightguides (optical fibers) resists water-, oil-, and dirt-repellent coatings and other advanced applications [14]. Several rather complex methods to prepare the a-fluoroalkyl monomers (e.g., a-phenyl fluoroacrylates, a-(trifluoromethyl) acrylic and its esters, esters of perfluoromethacrylic acid) exist and are discussed in some detail in [14]. Generally, a-fluoroacrylates polymerize more readily than corresponding nonfluorinated acrylates and methacrylates, mostly by free radical mechanism [15], Copolymerization of fluoroacrylates has been carried out in bulk, solution, or emulsion initiated with peroxides, azobisisobutyronitrile, or y-irradiation [16]. Fluoroalkyl methacrylates and acrylates also polymerize by anionic mechanism, but the polymerization rates are considerably slower than those of radical polymerization [17]. 

For applications in CO2, silicones are generally considered less effective than their fluorinated counterparts. Poly(dimethyl siloxane) (PDMS) solubility in CO2 was first reported in 1996 at a level of 4 %wt, PDMS n 13k) is soluble in CO2 at 35 °C and 277 bar (55). Block copolymer surfactants consisting of C02-philic PDMS and C02-phobic ionizable poly(methaciylic acid) (PMA) or poly(acrylic acid) (PAA) were used to form w/c and c/w emulsions (17). These PDMS-based block copolymers exhibited remarkable ambidextrous behavior to stabilize PPMA particles both in CO2 on the one hand, and in water on the other hand (56, 57). Steric stabilization is imparted in CO2 by PDMS, which is significantly more soluble in a CO2/MMA mixture than in pure CO2 (58). 

All TP or TS matrix property can be improved or changed to meet varying requirements by using reinforcements. Typical thermoplastics used include TP polyesters, polyethylenes (PEs), nylons (polyamides/ PAs), polycarbonates (PCs), TP polyurethanes (PURs), acrylics (PMMAs), acetals (polyoxymethylenes/POMs), polypropylenes (PPs), acrylonitrile butadienes (ABSs), and fluorinated ethylene propylenes (FEPs). The thermoset plastics include TS polyesters (unsaturated polyesters), epoxies (EPs), TS polyurethanes (PURs), diallyl phthalates (DAPs), phenolics (phenol formaldehydes/PFs), silicones (Sis), and melamine formaldehydes (MFs). RTSs predominate for the high performance applications with RTFs fabricating more products. The RTPs continue to expand in the electronic, automotive, aircraft, underground pipe, appliance, camera, and many other products. 

The first dendrimers made were based on PAMAM (Tomalia et al. 1985). It was also the first to be scaled up and commercialized under the name of starburst dendrimers. Poly(propylene imine) (PPI) and poly(ethylene imine) (PEI) are some of the other commonly used dendrimers for drug and gene delivery. Since then, many new dendrimers have been synthesized that possess various properties for specific applications. Incorporation of inorganic molecules into dendrimer structures has shown distinct advantages. For example, the recent carbosilane dendrimers with surface lactose entities seem to possess inherent antiviral properties (Oka et al. 2009). In another case, fluorine molecules were incorporated into the core of dendrimers (Jiang and Yu 2010) that offer potential in fields such as catalysis. Polyester (Padilla De Jesus et al. 2002), polypeptide (Choe et al. 2002), triazine (Lim and Simanek 2008), and poly glycerol (Calderon et al. 2009) are organic dendrimers that have been attached to chemothera-peutics to increase the efficacy of treatment. Many other useful chemical compositions such as the poly (ester acrylate/amide) (PEA) (Swanson et al. 2007) and poly(ether hydroxylamine) (PEHAM) (Tomalia et al. 2006) are commercially available and used in biomedical applications. 

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