Polyvinyl cyclohexane

FIGURE 13.1 Stereoviews along the main chain of helical structures exhibited by isotactic poly(oi-olefins), with a single atom representing the side chains (a) a threefold helix (3 j -polypropylene) and (b) a fourfold helix (4i-polyvinyl cyclohexane). 

Bands of Vinylcyclohexane Units. The IR spectrum of polyvinyl-cyclohexane is relatively insensitive to stereor ularity (44), the only regularity band being observed at 952cm . The study of vinylcyclohexane copolymers 43,44,46) showed that the 885 cm" barxl (one of the components of the strong 892-885 cm" pair assigned to the ring mode) probably corresponds to the absorption of the units in blocks, but not to that of isolated units (43). 

Polybutylcyanoacrylates [63], polyacrylics [64], polybutadiene [65], flame retardant PE [66], PS [67-70], PS - divinyl benzene copolymer [71], PS - acrylonitrile copolymer [72], acrylonitrile-butadiene-styrene terpolymer [73, 74], styrene-maleic anhydride copolymer [75], polyvinyl-cyclohexane [76], polyphenylene triazine [77], poly-4-vinyl pyridine [78], polyethylene sulfide [79], PSF [80], brominated PES [81], tetrafluoroborate doped polythiophene [82], polysiloxane [56, 83], vinyl pyrrolidone-methacryloxy silicone copolymer [50], polyvinyl indene [84], poly-E-lactide [3, 85, 86], epoxy resins [87, 88], polyaryl ether ketone [89, 90], ethylene... 

The stabilising action of the adsorption layers from high molecular substances (protective colloids) is related to the decrease in the forces of molecular attraction. Hence, films from aqueous solution of polyvinyl alcohol obtained between drops of cyclohexane have thickness of 80 nm and respectively, a very low attraction force, in contrast to black films [513]. Along with that the adsorption layers from such compounds possess visco-elasticity properties with modulus of elasticity 104 N m"2, impeding the film thinning and drop coalescence [503]. 

A significant number of works are concerned with the development of new membranes for the separation of mixtures of aromatic/alicyclic hydrocarbons [10,11,77-109]. For example, the following works can be mentioned. A mixture of cellulose ester and polyphosphonate ester (50 wt%) was used for benzene/cyclohexane separation [113]. High values of the separation factor and flux were achieved (up to 2 kg/m h). In order to achieve better fluxes and separation factors the attention was shifted to the modification of polymers by grafting technique. Grafted membranes were made of polyvinylidene fluoride with 4-vinyl pyridine or acrylic acid by irradiation [83]. 2-Hydroxy-3-(diethyl-amino) propyl methacrylate-styrene copolymer membranes with cyanuric chloride were prepared, which exhibited a superior separation factor /3p= 190 for a feed aromatic component concentration of 20 wt%. Graft copolymer membranes based on 2-hydroxyethyl methylacrylate-methylacrylate with thickness 10 pm were prepared [85]. The membranes yielded a flux of 0.7 kg/m h (for feed with 50 wt% of benzene) and excellent selectivity. Benzene concentration in permeate was about 100 wt%. A membrane based on polyvinyl alcohol and polyallyl amine was prepared [87]. For a feed containing 10 wt% of benzene the blend membrane yielded a flux of 1-3 kg/m h and a separation factor of 62. 

Sarkhel D, Roy D, Bandyopadhyay M, and Battacharya P. Studies on separation characteristics and pseudo-equihbrium relationship in pervaporation of benzene/cyclohexane through composite polyvinyl alcohol membranes with polyacrylonitrile supports. Sep Purif Technol 2003 30 89-96. 

Yamazaki A and Mizoguchi K. Pervaporation of benzene/cyclohexane and benzene/u-hexane mixtures through polyvinyl alcohol membranes. J Appl Polym Sci 1997 64 1061-1065. 

Polyvinyl chloride Nitrocellulose and cellulose acetates Cellulose acetobutyrate Cyclohexane Acetone Methyl ketone Glycol Water Isopropyl ether... 

Vinylon. See Polyvinyl alcohol Vinyloxy-cyclohexane. See Cyclohexyl vinyl ether... 

With loose structures of linear molecules the exponent for instance to cellulose nitrate in acetone, precipitated by water, to Polyvinyl acetate in toluene, precipitated by a methanol-water mixture-, and to the methyles-ters of polymethacrylic acid in benzene, precipitated by cyclohexane With compact spherical particles we must expect n-values in the neighbourhood of 2/3, since in this case only the outer surface of the particles is subject to the action of the medium. Examples can be found in some proteins. Finally, if the long-chain molecule shows a pronounced ramification or if the randomly kinked structure is comparatively close-packed, n may assume values between 0.7 and 1. This is shown for instance, by branched polystryrene h by acetyl-starch and by glycogene An accurate check on the value of n, however, is usually impossible. Husemann s experiments with glycogene, for instance, can be equally well described by n = 2/3 as by n — J (Fig. 5). This is due to the fact that the value of P in this method is not unlimited. In practice the upper limit of the molecular weight lies in the neighbourhood of 5.10, the lower limit lies in the further to be noted that the constant b in equation... 

Other polymers which have been the subject of thermal degradation studies include ethylene-vinyl acetate [29, 66, 67], ethylene-vinyl alcohol [68], poly(aryl-ether ketone) [69], poly-2-vinyl-naphthalene-co-methyl maleate [34], polyphenylenes based on diethyl-benzophenone [70], polyglycollide [71-73], poly(a-methylstyrene tricarbonyl chromium [74], polytetrahydrofuran [75], polylactide [76-78], poly(vinyl) cyclohexane [79], styrene-vinyl cyclohexane [80], isopropenylacetate-maleic dianhydride [80], polyethylene glycol containing a 1,3-disubstituted phenolic group [81], poly-2-vinyl naphthalene-co-methacrylate [34], collagen biopolymers [82], chitin graft poly (2-methyl-oxazoline - polyvinyl chloride blends [83], cellulose [32, 83-88] and side-chain cholestric elastomers [89, 90]. 

PS Cyclohexane, methyl-cyclohexane, acetone, tert-butyl acetate, ethyl acetate, ethyl oxalate, vinyl acetate, ethyl malonate, methyl acetate, methyl succinate, octene, polyvinyl acetal/chloroform, mbber/benzaie, toluene/ethanol... 

IZU Izumi, Y., Dondos, A., Picot, C., and Benoit, H., Etude des solutions de polymeres dans un melange de solvants au voisinage de leur point critique de demixtion, 1. Systeme methanol/cyclohexane/polyvinyl-2-pyridine, A/aArowo/. Chem., 180, 2483, 1979. 

Polyvinyl Chloride (flexible) Softness range is that of rubber, extensibility proportionate to plasticizer used Bums with yellowish sooty flame, melts freely to form pearl like drops Flame turns green Sharp acrid fumes turn Congo paper blue Cyclohexane, tetrahydrofiiran and pyridine, solution turns red in presence of alcoholic potassium hydroxide solution... 

Some specific recent applications of the GC-MS technique to various types of polymers include the following PE [49,50], poly(l-octene) [51], poly(l-decene) [51], poly(l-dodecene) [51], 1-octene-l-decene-l-dodecene terpolymer [51], chlorinated polyethylene [52], polyolefins [53, 54], acrylic acid methacrylic acid copolymers [55], polyacrylates [56], styrene-butadiene and other rubbers [57-59], nitrile rubber [60], natural rubbers [61, 62], chlorinated natural rubber [63, 64], polychloroprene [65], PVC [66-68], silicones [69, 70], polycarbonates [71], styrene-isoprene copolymers [72], substituted PS [73], polypropylene carbonate [74], ethylene-vinyl acetate copolymers [75], Nylon [76], polyisopropenyl cyclohexane a-methyl styrene copolymers [77], m-cresol-novolac epoxy resins [78], polymeric flame retardants [79], poly(4-N-alkyl styrenes) [80], polyvinyl pyrrolidone [81], vinyl pyrrolidone-methyl acryloxysilicone copolymers [82], polybutylcyanoacrylate [83], polysulfide copolymers [84], poly(diethyl-2-methacryloxy)ethyl phosphate [85], ethane-carbon monoxide copolymers [86], polyetherimide [87], bisphenol A [88], ethyl styrene [89], styrene-isoprene block copolymer [89], polyvinyl alcohol-co-vinyl acetate [90], epoxide thiol [91], maleic acid-propylene copolymer [92], P-hydroxy butyrate-P-hydroxy valerate copolymer [93], polycaprolactams [39,94], PS [95,96], polypyrrole [95,96], polyhydroxy alkanoates [97], poly(p-chloromethyl) styrene [81], polybenzooxazines and siloxy substituted polyoxadisila-pentanylenes [98,99] poly benzyl methacrylates [100], polyolefin blends after ageing in soil [101] and polystyrene peroxide [43]. 

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