Styrene-methylmethacrylate mixture

PB grafted with styrene, methylmethacrylate, and maleic anhydride (ABSM-MA) or a mixture of ABS and SMM-MA processability, high impact strength, mechanical properties Dufour, 1982... 

We may find confirmation for our statement about the thermodynamic incompatibility of linear polystyrene with the styrene-DVB copolymer in experiments by Wong et al. [269]. These authors reported similarities in the phase separation power of linear polystyrene and that of linear styrene-methylmethacrylate copolymer, the latter being a priori incompatible with the styrene-DVB network. Complete incompatibility of polystyrene with linear polydimethylsiloxane facihtates phase separation and results in the formation of a porous styrene-DVB network on adding as little as 0.5-1% of the above porogen to the initial comonomer mixture (Fig. 3.2, curves 4). It is also not surprising that the porosity of copolymers induced by linear polystyrene and linear polydimethylsiloxane is almost the same when the DVB content exceeds 10%. At a DVB content that hi, the network formed differs fundamentally from linear polystyrene, as from any alien polymer. 

Saha and co-workers [70] and Palit [66, 67] developed a dye-partition method for the determination of halogen atoms in copolymers of styrene, methylmethacrylate, methylacrylate, or vinyl acetate with a chlorine-bearing monomer such as allyl chloride and tetrachloroethylene. Copolymers were quaternised with pyridine, then precipitated with petroleum ether or alcohol, and fnrther purified by repeated precipitation from their benzene solutions with a mixture of alcohol and petroleum ether as the non-solvent. The precipitated polymers were then washed with petroleum ether and dried in air. The test for quaternary halide groups in polymers was carried out with a reagent consisting of disulfine blue dissolved in 0.01 M hydrochloric acid and the colour evaluated spectrophotometrically at 630 nm. Saha and co-workers [70] and Palit [66, 67] found that there may be some imcertainty in the quantitative aspects of this method. 

Non-aqueous (or-oil-in-oil) emulsions, where the phases are two immiscible organic liquids, have received relatively little attention in the literature. Riess et al. [116-119] have studied the stabilisation of waterless systems with block and graft copolymers, where one of the liquids is a good solvent for one of the blocks and a non-solvent for the other, and vice versa. Thus, poly(styrene-b-methylmethacrylate) copolymers could emulsify acetonitrile/cyclohexane mixtures, and poly(styrene-b-isoprene) was effective for DMF/hexane systems [116]. These, however, are not HIPE systems. 

All copolymerizations were carried out with 50 50 mixtures of the two co-monomers. MMA-methylmethacrylate, BA - n-butylacrylate, ERA - ethylhexylacrylate, STY - styrene, TMSiSTY - p-trimethylsilyl-styrene. 

OFM are viscous liquids, or readily fusible resinTike substances, capable (in the presence of intiators or upon irradiation) of three-dimensional radical copolymerization with several active monomers (styrene, vinyltoluene, methylmethacrylate and others). The properties of the network copolymers formed largely depend on the chemical nature of the reagents and the copolymerization conditions. Hardening of OFM may be carried out at room temperature, or even lower, using mixtures... 

He was aware that termination reactions were of little importance, since successive additions of monomer could be made to polymerize after the complete reaction of the first added portion, even after the reaction mixture had been allowed to stand for some time. The relative efficiency of a group of initiators was also described. In the polymerization of butadiene, for instance, the deep red colour of cumylpotassium disappeared almost immediately, whereas with triphenylmethylsodium, the colour persisted during the polymerization process. With metallic sodium initiation, polymerization was shown to proceed at both ends of the polymer chain via an a,co-disodium adduct of the diene. It can be said, therefore, that by 1936 the essential characteristics of the process had been described, but interest in this topic was limited for many years afterwards. A few papers appeared in the literature. Beaman [6], in 1948, described the polymerization of methacrylonitrile and methylmethacrylate by sodium and triphenylmethylsodium in liquid ammonia, and similar experiments with styrene were described in 1949 [7, 8] using sodium or potassium amide as initiator. 

A few other methods have been used to prepare polypeptide hybrid copolymers. Inoue polymerized Bn-Glu NCA off of amine-functionalized styrene derivatives, and then copolymerized these end-functionalized polypeptides with either styrene or methyl methacrylate using free radical initiators to yield hybrid comb architecture copolymers [38]. Although unreacted polypeptide was identified and removed by fractionation, copolymers were obtained with polypeptide content that increased with feed ratio. There was no mention if the polypeptide interfered with the radical chemistry. In similar work, Imanishi and coworkers converted the amine-ends of polypeptides to haloacetyl groups that were used to initiate the free radical polymerization of either styrene or methylmethacrylate to yield hybrid block copolymers [39]. Studies using CPC showed that the crude product contained mixtures of copolymers and homopolymers, and so removal of the homopolymers by extraction was necessary. 

The first mechanical blends of NBR with SAN, known as type-A ABS, date from 1936. In the mid-1940 s, Dow started emulsion polymerization of ABS type-G . By the late 1950 s, the high heat ABS were invented, viz. interpolymers of a-methylstyrene and acrylonitrile [Irving, 1961] a mixture of methylmethacrylate-a-methylstyrene either with styrene-grafted polybutadiene (SBR) or with an ABS [Kanegafuchi, 1967] a mixture of SMA and ABS [Stafford and Adams, 1972] a mixture of SMA with ABS and MBS [Tatuhiko and Akira, 1982] a mixture of SMA-MMA with ABS, etc. 

Monomethyl maleic ester of epoxidised soybean oil (MESO) is prepared by the reaction of epoxidised oil with monomethyl maleate with AMC-2 catalyst. (AMC-2 is a mixture of 50% trivalent organic chromium complexes and 50% phthalate esters). This MESO is photo-polymerised with ultraviolet light and free radically homopolymerised and copolymerised with styrene, vinyl acetate and methylmethacrylate. MESO may also be reacted with maleic anhydride at the newly formed hydroxyl groups to give maleinised MESO. Thus a large number of resinous systems may be made from the epoxidised oil. 

These multicomponent PP blends have been developed during the last ten years. For example, they comprise (1) either an acidified-PP, its mixture with PP, or a mixture of PP with carboxylic acid-modified EPR (2) poly(methylmethacrylate-co-styrene-co-maleic anhydride) and (3) either ethylene-methylmethacrylate-glycidylmethacrylate, or ethylene-vinylacetate-glycidylmethacrylate. The compatibilization is obtained by chemical reactions between the acid and epoxy groups, as well as by forming ionic clusters capable of forming thermoreversible crosslinks. The blends were used to mold car bumpers and fenders. The products showed good stiffness and low-temperature impact resistance [8]. 

Cannas, A. Marongiu, B. Porcedda, S. Excess enthalpies of 14 binary mixtures containing low molecular mass analogues of polymers acrylonitrile, methylmethacrylate, or styrene oxide ELDArA/nt. Electron. J. Phys.-Chem. Data 1997,5,119-130... 

The ESR technique has permitted to identify initial rupture points in mechanically degraded copolymers. Lazar and Szocs [53] investigated random, block, and graft copolymers of methylmethacrylate (MMA) and styrene (S). They found in a degraded mixture of equal parts MMA and S homopolymers equal concentrations of MMA and S radicals. In a random copolymer (MMA S = 1 1) the styrene radical prevailed clearly. By comparing the reactions of mechano-radicals in ball-milled PP with those of 7-radicals Kurokawa et al. [54] concluded that the mechano-radicals were produced and trapped on the fresh surfaces created by the breaking-up of solid polypropylene. 

---