Vinyl aromatic polymers

Polystyrene and polypropylene are normally immiscible, but they have been successfully compatibilised by PP grafted with an aromatic vinyl polymer. 

Frank CW, Gashgari M-A, Chutikamontham P, Haverly VI (1980) Excimer fluorescence as a molecular probe of polymer blend compatibility II. The effect of concentration on blends of aromatic vinyl polymers with poly (alkylmethacrylates). In Structure and properties of amorphous polymers proceedings of the second Cleveland symposium on macromolecules, Elsevier, Cleveland, OH, 31 October-2 November 1978, p 187... 

Gelles R, Frank CW (1982) Energy migration in the aromatic vinyl-polymers. 2. Miscible blends of polystyrene with polyvinyl methyl-ether). Macromolecules 15(3) 741-747. doi 10. 1021/ma00231a012... 

Thomas JW, Erank CW (1985) Energy migration in the aromatic vinyl-polymers. 4. Blends of poly(2-vinylnaphthalene) with poly(cyclohexyl methacrylate). Macromolecules 18 (5) 1034-1039. doi 10.1021/ma00147a039... 

Synthetic fibres with ion-exchange properties were obtained from tapes extruded from polystyrene or its mixtures with polyethylene or polypropylene, by chlorosulfonation by chlorosulfonic acid for cross-linking, followed by treatment with aniline. Ion-exchange composite spun fibres have also been synthesized from a thermoplastic polymer and an aromatic vinyl polymer by immersion of the drawn fibres in chlorosulfonic acid at 20 °C, followed by treatment with dichloromethane, methanol and 10% sodium hydroxide, and drying to yield fibres with an ion-exchange capacity of 2.1 mequiv.g" . ... 

Plasticizers. Plasticizers are materials that soften and flexibilize inherently rigid, and even britde polymers. Organic esters are widely used as plasticizers in polymers (97,98). These esters include the benzoats, phthalates, terephthalates, and trimeUitates, and aUphatic dibasic acid esters. Eor example, triethylene glycol bis(2-ethylbutyrate) [95-08-9] is a plasticizer for poly(vinyl butyral) [63148-65-2] which is used in laminated safety glass (see Vinyl POLYMERS, poly(vinyl acetals)). Di(2-ethyUiexyl)phthalate [117-81-7] (DOP) is a preeminent plasticizer. Variation of acid and/or alcohol component(s) modifies the efficacy of the resultant ester as a plasticizer. In phthalate plasticizers, molecular sizes of the alcohol moiety can be varied from methyl to tridecyl to control permanence, compatibiUty, and efficiency branched (eg, 2-ethylhexyl, isodecyl) for rapid absorption and fusion linear (C6—Cll) for low temperature flexibiUty and low volatility and aromatic (benzyl) for solvating. Terephthalates are recognized for their migration resistance, and trimeUitates for their low volatility in plasticizer appHcations. 

Whatever the approach, the result is a difficult-to-analyse system. Such options suit polymer producers better than additive suppliers. Aromatic polymers (PPO) have been mentioned as char-forming FRs. Polymeric UV absorbers, blended in proper proportions with commercial plastics, have potential use as stabilisers for fibres, films and coatings. Several monomeric stabilisers containing a vinyl group were homopolymerised and used as stabilisers for PE, PVC, acrylates, polystyrene, cellulose acetate and several vinyl polymers [55]. 

Note 1 In most cases (e.g., in vinyl polymers, polyamides) degradation is accompanied by a decrease in molar mass. In some cases (e.g., in polymers with aromatic rings in the main chain), degradation means changes in chemical structure. It can also be accompanied by cross-linking. 

In general, the photoresists exhibit greater dry-process resistance than the vinyl polymers of Table II. The greater dry-etch resistances of photoresists is attributed to the aromatic nature of the crosslinking agents, photoactive components, and novolac resins (positive photoresists only). In addition, the... 

Excimer formation has been shown to be a diffusion controlled process 41-43 in which a sandwich or face-on configuration of the two interacting molecules is required.44-48 It has been deduced that intermolecular distance in the excimer state is smaller than for the same configuration with both molecules in their electronic ground states.44-48 Apart from pyrene, excimer-like emission has been observed from a wide range of aromatic compounds including many alkyl derivatives of such hydrocarbons43-47 and vinyl polymers.48-80... 

The most widely used nomenclature in the field of luminescence of aromatic molecules is that proposed by Birks. 3) The photophysical species and processes in this scheme which are encountered in rigid systems of aryl vinyl polymers are described in Tables 1-4. Triplet excimers have been omitted since it will be shown later that all triplet states play minor roles in the room-temperature, air saturated P2VN blends studied recently 2). 

By chain backbone is understood the polymer chain proper without side groups and branches. For instance, all vinyl polymers have two atoms per structural unit in the chain backbone. If an aromatic ring is part of the backbone, Z is counted as follows o-phenylene, Z = 2 m-phenylene, Z = 3 p-phenylene, Z = 4. For alicyclic rings the same rule is applied. 

F 2. — Cross-linked aromatic vinyl co-polymers. Brit. Pat. 885.720 (1961). 

The polyene chain further decomposes under the influence of heat, generating aromatic hydrocarbons such as benzene, styrene, naphthalene, etc. This type of reaction can be the source of some polycyclic aromatic hydrocarbons found in traces during the pyrolysis of certain vinyl polymers. The elimination of a HX molecule from a vinyl type polymer is favored by the presence of a p-double bond in a compound of the form -CH2-CHX-CH=CH-. For this reason the side reaction for vinyl polymers is slower for the intact polymer and accelerates as the polymer tends to decompose. 

Conventional Photoresists. PE rate ratio values for several positive photoresists are also included in this study (see Table II), because several of these novolac resin containing formulations also function as positive e-beam and x-ray resists. Generally speaking, these formulations are more dry-process compatible than most of the vinyl systems (see also ref.2). This is due primarily to the aromatic nature of the novolak resins in the photoresists. Thus, the photoresist PE rate ratio data is close in value to those of the aromatic vinyl and negative behaving polymers. 

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