Polystyrene methyl methacrylate-hydroxyethyl

Similar increases in k with ultrasonic intensity have been found for other polymers such as polystyrene [44], poly(methyl methacrylate) [45], poly(dimethylsiloxane) [46], poly(ethyleneoxide), hydroxyethyl cellulose, poly(vinyl acetate), poly(acrylamide)... 

S47H10M43 82 Polystyrene-bfocfc-poly (2-hydroxyethyl methacrylate)- focfc-poly(methyl methacrylate)... 

The latices studied were composed primarily of either polystyrene or a copolymer of -butyl acrylate and methyl methacrylate. Their diameters were of order 0-4yjan. Hydroxyethyl cellulose was the water soluble polymer subjected to detailed investigations, but poly(oxyethylene) and polyacrylamide exhibited a qualitatively similar pattern of flocculation behaviour. Six different samples of hydroxyethyl cellulose were studied, their molecular weights varying from 68 500 to 887 000. 

The properties of the microenvironment of soluble synthetic polymers such as polymethacrylamide (PMA), poly(2-hydroxyethyl methacrylate) (PHEMA), poly(2-vinylpyridine) (P-2VP), poly(4-vinylpyridine) (P-4VP), poly(methyl methacrylate) (PMMA), poly(butyl methacrylate) (PBMA), polystyrene (PS), poly(4[5]-vinylimidazole) (PVIm), and poly(N-2-hydroxypropyl methacrylamide) (PHPMA) and cross-lined polymers were studied by the shift and shape of the band in electronic spectra of a solvatochromic "reporter" molecule embedded in polymer chains. Preferential interaction of parts of the polymer molecule with a reporter and the shielding of interactions between solvent molecules and a reporter molecule of a polymer causes a shift and broadening of its solvatochromic band. This shift is mechanistically interpreted as a change in the polarity of the microenvironment of a polymer in solution in comparison with polarity of the solvent used. 4-(4-Hydroxystyryl)-N-alkylpyridinium-betaine, spiropyran-merocyanine, and l-dimethylamino-5-sulfonamidonaphthalene (Dansyl) reporters were used. In almost all cases the polarity of the polymer microenvironment was lower than that of the solvent. At the same time, the dependence of the nature of the environment on the distance of the reporters from the polymer chain was studied. 

Until 2003, Chen s [28], Qu s [29-31], and Hu s [32] groups independently reported nanocomposites with polymeric matrices for the first time the. In Hsueh and Chen s work, exfoUated polyimide/LDH was prepared by in situ polymerization of a mixture of aminobenzoate-modified Mg-Al LDH and polyamic acid (polyimide precursor) in N,N-dimethylactamide [28]. In other work, Chen and Qu successfully synthesized exfoliated polyethylene-g-maleic anhydride (PE-g-MA)/LDH nanocomposites by refluxing in a nonpolar xylene solution of PE-g-MA [29,30]. Then, Li et al. prepared polyfmethyl methacrylate) (PMMA)/MgAl LDH by exfoliation/adsorption with acetone as cosolvent [32]. Since then, polymer/LDH nanocomposites have attracted extensive interest. The wide variety of polymers used for nanocomposite preparation include polyethylene (PE) [29, 30, 33 9], polystyrene (PS) [48, 50-58], poly(propylene carbonate) [59], poly(3-hydroxybutyrate) [60-62], poly(vinyl chloride) [63], syndiotactic polystyrene [64], polyurethane [65], poly[(3-hydroxybutyrate)-co-(3-hydroxyvalerate)] [66], polypropylene (PP) [48, 67-70], nylon 6 [9,71,72], ethylene vinyl acetate copolymer (EVA) [73-77], poly(L-lactide) [78], poly(ethylene terephthalate) [79, 80], poly(caprolactone) [81], poly(p-dioxanone) [82], poly(vinyl alcohol) [83], PMMA [32,47, 48, 57, 84-93], poly(2-hydroxyethyl methacrylate) [94], poly(styrene-co-methyl methacrylate) [95], polyimide [28], and epoxy [96-98]. These nanocomposites often exhibit enhanced mechanical, thermal, optical, and electrical properties and flame retardancy. Among them, the thermal properties and flame retardancy are the most interesting and will be discussed in the following sections. 

Triblock terpolymers of polystyrene-b/ocfe-poly (2-hydroxyethyl methacrylate)-l7/ocfe-poly(methyl methacrylate) (PS-I7-PHEMA-I7-PMMA) with symmetrical end blocks and short middle block have been aligned by applying electric field.2 The thin film stmcture was formed by lateral arrangement of PS and PMMA lamellae, while the middle block was preferentially adsorbed to the polar substrate. This structure was aligned under electric field, so that the lamellae oriented along the field lines, as shown in Figure 46(b). 

PS—polystyrene UF—urea-formaldehyde resin glut—glutaraldehyde thio— thiourea BSA—bovine serum albumin PHEMA—poly(hydroxyethyl methacrylate) IDA—iminodiacetic acid LDH—lactate dehydrogenase OPS—o-phosphoserine 8HQ—8-hydroxyquinoUne Bpa— bis(2-pyridyl-methyl) amine. 

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