Poly styrene preparation

When a 0.8006-g sample of a poly(styrene/maleic anhydride) copolymer was prepared in the same manner, the following results were obtained... 

A review covers the preparation and properties of both MABS and MBS polymers (75). Literature is available on the grafting of methacrylates onto a wide variety of other substrates (76,77). Typical examples include the grafting of methyl methacrylate onto mbbers by a variety of methods chemical (78,79), photochemical (80), radiation (80,81), and mastication (82). Methyl methacrylate has been grafted onto such substrates as cellulose (83), poly(vinyl alcohol) (84), polyester fibers (85), polyethylene (86), poly(styrene) (87), poly(vinyl chloride) (88), and other alkyl methacrylates (89). 

In the sol-gel procedure for the preparation of hybrids, polymeric acid catalysts such as poly (styrene sulfonic acid) were also used instead of hydrogen chloride [14]. The polymeric acid catalyst was effective for the preparation of hybrids at a similar level to that of hydrogen chloride catalyst. In some cases, the increased modulus was observed due to the higher extent of reaction. No difference was observed in morphologies between the hybrids prepared with polymeric and small molecule acid catalysts. The method using polymeric acid catalyst may depress the ion-conductive property, characteristic to the mobile acidic small molecules. Polymeric catalyst may also influence the rheology of the resulting hybrids. 

For these reasons, despite the apparent advantages and also despite the fact that bulk polymerisation is so often the method of choice for the laboratory preparation of vinyl polymers, this technique is not widely used in industry. Only three polymers are produced in this way, namely poly(ethylene), poly(styrene), and poly(methyl methacrylate). 

The term IPN was first used in 1960 to describe the apparently homogeneous product obtained from styrene crosslinked with divinylbenzene. IPNs were prepared from this system by taking a crosslinked poly(styrene) network and allowing it to absorb a controlled amount of styrene and a 50% divinylbenzene-toluene solution containing initiator. Polymerisation of this latter component led to the formation of an IPN, the density of which was... 

Since this pioneering work a number of IPNs have been prepared. Poly(styrene) has been used as the second network polymer in conjunction with several other polymers, including poly(ethyl acrylate), poly(n-butyl acrylate), styrene-butadiene, and castor oil. Polyurethanes have been used to form IPNs with poly(methyl methacrylate), other acrylic polymers, and with epoxy resins. 

Poly(styrene-/7-isobutylene-/ -styrene) (PS-PIB-PS), triblock copolymers can be prepared via coupling of living PS-PIB diblock copolymers in a one-pot procedure [12]. 

Poly(styrene-fc-butadiene) copolymer-clay nanocomposites were prepared from dioctadecyldimethyl ammonium-exchanged MMT via direct melt intercalation [91]. While the identical mixing of copolymer with pristine montmorillonite showed no intercalation, the organoclay expanded from 41 to 46 A, indicating a monolayer intercalation. The nanocomposites showed an increase in storage modulus with increasing loading. In addition, the Tg for the polystyrene block domain increased with clay content, whereas the polybutadiene block Tg remained nearly constant. 

Chemical composition of packings. Today, a wider variety of different support materials is available from which to choose. Silica is still widely used, though preparative grades often possess a relatively wide particle size distribution as compared to polymer-based supports. One serious limitation of silica-based supports is the low stability of silicas to alkaline pH conditions, which limits use of caustic solutions in sanitization and depyrogenation. Polymer-based supports, which include poly(styrene-divi-nyl benzene)- or methacrylate-based materials, are widely available and have gained increased acceptance and use. Nonfunctionalized poly(styrene-divinyl... 

Brown and White employed this approach to prepare block copolymers of styrene and mcthacrylic acid (6). They were able to hydrolyze poly(styrene-b-methyl methacrylate) (S-b-MM) with p-toluenesulfonic acid (TsOH). Allen, et al., have recently reported acidic hydrolysis of poly(styrene-b-t-butyl methacrylate) (S-b-tBM) (7-10). These same workers have also prepared potassium methacrylate blocks directly by treating blocks of alkyl methacrylates with potassium superoxide (7-10). 

Preparation of Block Copolymers. Poly(styrene-b-methyl methacrylate) and poly(styrene-b-t-butyl methacrylate) were prepared by procedures similar to those reported for poly(styrene-b-methyl methacrylate (12,13). Poly(methyl methacrylate-b-t-butyl methacrylate) was synthesized by adaptation of the method published (14) for syndiotactic poly(methyl methacrylate) polymerization of methyl methacrylate was initiated with fluorenyllithium, and prior to termination, t-butyl methacrylate was added to give the block copolymer. Pertinent analytical data are as follows. 

Virklund, C., Nordstrom, A., Irgum, K. (2001). Preparation of porous poly(styrene-co-divinylbenzene) Monoliths with controlled pore size distributions initiated by stable free radicals and their pore surface functionalization by grafting. Macromolecules 34, 4361-... 

A combination of TEMPO living free radical (LFRP) and anionic polymerization was used for the synthesis of block-graft, block-brush, and graft-block-graft copolymers of styrene and isoprene [201]. The block-graft copolymers were synthesized by preparing a PS-fo-poly(styrene-co-p-chloromethylstyrene) by LFRP [Scheme 110 (1)], and the subsequent re-... 

Attractive interactions are also the reason for the self-assembly of PS-fo-PB-fo-PMMA at the interface of poly(styrene-co-acrylonitrile), SAN, and poly(2,6-dimethylphenylene ether), PPE. In this blend, PS and PPE are miscible on one side and PMMA and SAN are miscible on the other one, with negative / parameters. This blend, in which the rubbery domain is located at the interface between SAN/PMMA and PPE/PS, was originally prepared by coprecipitation of all components from a common solution [195]. From a processing point of view, in this system the difficulty was to get the dispersion of PPE in SAN via melt mixing of SAN, PPE and the triblock terpolymer. 

CH2CpCo(C0)2 3 and CpCo(C0)2 were prepared utilizing the procedures of Grubbs et al. for the syntheses of poly-styrene-bound cyclopentadiene (25) and Rausch and Genetti for the synthesis of CpCo(C0)2 (26 ). Thus, for 3, commercially available (P)CH2C1 (1% DVB, microporous, 1.48 mmol Cl/g. resin) was treated with excess NaCp to form CH2CpH 2. This was then exposed to Co2(C0)e to form desired compound 3 (0.3-0.5 mmol Co/g. resin,... 

Chlorinated poly(styrene) samples were prepared by chlorination of PS with CI2 in trifluoroacetic acid(9) or by free radical chlorination using f-butyl hypochlorite(lO) or by chloromethylation using chloromethyl actyl ether and SnCU(ll). 

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