Poly sulphones vinyl polymers

The polyacrylate polymers and a derivative of a vinyl acetate maleic anhydride copolymer cause V30 to decrease monotonically with increasing polymer concentration, similar to the CMC polymers (Figure 46). The polymers PVA and poly(vinyl pyridinium) (PVP) hydrochloride markedly increased V30 at low concentration at concentrations above 1 g of polymer per gram of added bentonite PVA functions as a static fluid loss additive. The maximum in the API fluid loss at low PVA concentrations approximately coincides with the maximum in the yield stress and plastic viscosity found by Heath and Tadros (75). The increased static fluid loss is consistent with Heath and Tadros s conclusion that bentonite is flocculated by low concentrations of PVA. The concentration of PVA required to decrease V30 below that of the neat bentonite suspension is significantly larger than the concentration of CMC, where effective static fluid loss control can be achieved at polymer bentonite weight ratios of about 0.1 g/g. More effective fluid loss control has been achieved with other synthetic polymers such as poly(vinyl sulphonate)-poly(vinyl amide) copolymer (40) and other sulphonated polymers (39). 

Anionic polyelectrolytes (PE), such as potassium poly-(vinyl-sulphate) (PVSK), (sodium poly(styrene-4-sulphonate) (PSSNa) and Nafion, were incorporated in conducting polymer according to the same procedure as described above, and charge-controllable conducting polymer membranes were obtained [15-17]. 

Field flow techniques have been reviewed in a number of articles [148-150]. Sedimentation field flow fractionation has found use in the separation of PVC [151, 152], polystyrene [151-153], poly(methyl methacrylate) [153, 154], poly (vinyl toluene) [155] and poly(glycidyl methacrylate) latexes [156] to produce particle-size distributions and particle densities. It has also been applied in polymer-aggregation studies [157], pigment [157] quality control and in the separation of silica particles [158] and its performance has been compared with that of ultracentrifugation [159]. Thermal field flow fractionation has been used successfully in the characterisation of ultra-high-molecular-weight polystyrenes [160, 161], poly(methyl methacrylate), polyisoprene, polysulphane, polycarbonate, nitrocellulose, polybutadiene and polyolefins [162]. In the difficult area of water-soluble polymers, poly(ethylene glycol), poly(ethylene oxide), poly(vinyl pyrrolidone) and poly(styrene sulphonate) have been analysed [163, 164]. In addition, compositional separations have been achieved for polystyrene-poly(methyl methacrylate) mixes [165] and comparisons between TFFF and SEC have been made [166]. 

At high temperatures the image of photodegradation changes completely because additional reactions are involved in the thermal degradation of a polymer [1319]. Many papers have been devoted to the study of photothermal degradation of polyethylene [148,1289], polypropylene [822], poly(ethylene-co-carbon monoxide) [871, 917], polyacrylates and polymethacrylates [821, 829], poly(acrylate-co-methacrylate) [828, 831], poly(vinyl chloride) [311, 702, 768, 891,1097,1319,1792] polystyrene [1491], natural rubber [14] and poly(ether sulphone) [1265]. 

In addition, it has been shown that hy introducing groups capable of ion-ion, ion-dipole, and dipole-dipole interactions, it is possible to achieve miscibility between otherwise immiscible polymer pairs. For example, although polystjrrene and poly(ethyl acrylate) are immiscible polymers, miscibility can be achieved by introducing styrene sulphonic acid units in the PS chains and ethylacrylate can be copolymerized with small quantities of 4-vinyl pyridine (19). This system is now one-phase through the effect of coulombic attractions between the two copolymers (20-22). 

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