Polystyrene copolymer

An interesting application of the Paal thiophene synthesis was documented for the synthesis of a polystyrene-oligothiophene-polystyrene copolymer. In the Stetter reaction of aldehyde 13 and P-dimethylaminoketone 14, in situ generation of the a,p-unsaturated ketone preceded nucleophilic 1,4-conjugate addition by the acyl anion... 

NYLON (INCLUDING AROMATICSI THE RMOPLASTIC POLYESTERS (INCLUDING AROMATICSI POLYCARBON ATES / ALLOYS POLYSUIRONES POLYSTYRENE /COPOLYMERS IEXCEPT ABSl EPOXY... 

PPO BASED POLYARYL ETHOR OLASS-RElNFOftC(D SILICONS POLYSTYRENE COPOLYMERS... 

Itarou H., Mays I.W., and Hadjichri-Stidis N., Regular comb polystyrene and graft polyisoprene/ polystyrene copolymers with double branches ( Centipedes ). Quality of (l,3-phenylene)bis(3-methyl-l-phenylpentylidene)dilithium initiator in the presence of polar additives. Macromolecules, 31,6697, 1998. 

A similar simplifying assumption has been used by Allain et al.(90) in analyzing their experiments on a flexible fluorescent anthracene-polystyrene copolymer coil in the vicinity of a nonadsorbing wall. The analysis appears to confirm a local decrease in C(z) for small z at the solid/solution interface. Such a depletion layer is interpreted in terms of an entropic repulsion ... 

Kim, J., Kim, B. and Jung, B. 2002. Proton conductivities and methanol permeabilities of membranes made from partially sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene copolymers. Journal of Membrane Science 207 129-137. 

Carroll JB, Jordan BJ, Xu H, Erdogan B, Lee L, Cheng L, Tiernan C, Cooke G, Rotello VM. Model systems for flavoenzyme activity site-isolated redox behavior in flavin-functionalized random polystyrene copolymers. Org Lett 2005 7 2551-2554. 

If we consider that cell adhesion under biological circumstances is mainly brought about with the aid of preadsorbed protein on the material s surface, we may explain the unique behavior of amino-containing materials against the cell-adhesion process in terms of the reduced residence-time of protein molecules at the interface. Actually, a recent study [129] revealed that the surface of polyamine-gra/t-polystyrene copolymer (SA) containing 6 wt.% polyamine portion exhibited a minimal adsorptive property against bovine plasma fibronectin (FN) and vitronectin (VN), both of which are known to mediate cell-adhesion processes. 

A wide variety of polymers have been analyzed by gel-permeation, or size-exclusion, chromatography (sec) to determine molecular weight distribution of the polymer and additives (86—92). Some work has been completed on expanding this technique to determine branching in certain polymers (93). Combinations of sec with pyrolysis—gc systems have been used to show that the relative composition of polystyrene or acrylonitrile—polystyrene copolymer is independent of molecule size (94). Improvements in gpc include smaller cross-linked polystyrene beads having narrow particle size distributions, which allow higher column efficiency and new families of porous hydrophilic gels to be used for aqueous gpc (95). 

The incorporation of pendant Pcs to a polymeric backbone via the grafting of a suitable Pc molecule to a preformed polymer containing appropriate functional groups has been accomplished by Chen and co-workers [163], These authors exploited the axial reactivity of some metalloPcs (namely, In(III)Pcs) to prepare an In(III)Pc-polystyrene copolymer. The most remarkable feature of this material is that cofacial association between the macrocycles is fully prevented. For some applications of the Pcs, such as optical limiting or photodynamic therapy (PDT), aggregation should be avoided because it produces the quenching of the excited-states. 

Interchain copolymer formation Copolymers of reactive polystyrene and polymers with amide, mercaptan, epoxy, hydroxy, anhydride or carboxylic acid groups, copolymer of polypropylene grafted with maleic anhydride and nylon-6, copolymer of polyolefines and polystyrene, copolymer of EVA grafted with methacrylates and grafted polystyrene... 

The level of unpolymerised residual styrene monomer in commercial grades of polystyrene material has been reduced over the years from 1000 mg/kg (0.1 % w/w) to a target level of 500 mg/kg (0.05 % w/w) by more complete devolatilization after the polymerization step (Brighton 1982). The legal limits for styrene monomer in materials can be much higher (e.g. Australia 2500 mg/kg, AS 2070.3-1992). Hempel and Riidt (1988) carried out a survey of residual volatiles found in polystyrene and polystyrene copolymers whose results are summarized in Table 14-la. 

Low monomer content PS materials are commercially available with specified styrene monomer levels of 150 ppm (mg/kg) that have actual contents of 100 ppm (ex. BASF O suffix materials 168 NO, 143 IO). These materials can be used for injection molding or extrusion and are priced above normal styrene monomer content materials (those where styrene < 500 mg/kg). High impact polystyrene copolymer materials (HIPS) use normal monomer level polystyrene since there has been no commercial market for such materials. 

Chromosorb and Porapak series are divinylbenzene cross-linked polystyrene copolymers. Different members of the series vary in surface area and average pore diameter. Separations range from free fatty acids to free amines. Alcohols from methanol to pentanol can be separated on Porapak Q or Chromosorb 102. The maximum operating temperatiue is about 250°. 

POLYBROMNATED BIPHENYL see FBU509 POLYBROMINATED BIPHENYL see HCA500 POLYBROMINATED BIPHENYL (FF-1) see FBU509 POLYBROMINATED BIPHENYLS see FBUOOO POLYBUTADIENE-POLYSTYRENE COPOLYMER see SMROOO... 

Me, Ph, CjH FeCp) A series of fluorinated alcohol derivatives were also prepared.The addition of (Me2SiO)3 followed by Me3SiCl or further addition of cyclosiloxane gives slloxane or poly (slloxane) substituents. The addition of CO2 to the lithiated intermediate gives a carboxylate function which can be converted to the free acid or esterifled with p-nitrobenzylbromide. The addition of styrene to [NP(CH2Li)Ph] causes anonic polymerization of styrene and thus the formation of poly(methylphenylphosphazene)-graft-polystyrene copolymers. 

The combined use of continuous-glass-strand mat as a core material and uniformly and monoaxially aligned continuous-glass fiber as the surface material has also been proposed (5, 25). The incorporation of expanded polystyrene copolymers into composites was proposed for shock-absorbing composites, such as bumper beam cores, knee bolsters, etc. (17, 18). 

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