P-Methyl styrene

New copolymers based on a copolymerization of isobutylene and p-methyl-styrene with improved heat resistance have been reported [64]. Once copolymerization was accomplished, the polymer was selectively brominated in the p-methyl position to yield a terpolymer called EXXPO. In contrast to butyl and halobutyl, the new terpolymer has no unsaturation in the backbone and therefore shows enhanced thermal stability and resistance to oxidation. Useful solvent-based adhesives can be formulated using the new terpolymer in combination with block copolymers [65]. The hydrocarbon nature of the new terpolymer results in excellent compatibility with hydrocarbon resins and oils. 

The methyl substitution at a-position leads to an increase of the reactivity of styrene during polymerization as well as EDA-complex formation. However, the methyl substitution in p-position achieves an opposite effect. The strengthened complex formation connected with a further increase of the HOMO is faced with a drastically decreased polymerization rate. This can be explained by the well known steric effect of group hindrance around the p-C-atom under attack 72), as well as the polarity switch in the vinyl double bond. The p-C-atom in the p-methyl styrene possesses a... 

Sequential addition of a second monomer (e.g., styrene,p-terbutyl styrene, p-methyl styrene, indene, -chloro styrene, isoprene, and a-methyl styrene) to make glassy outer-block... 

Kumar et al. have studied the miUing behavior of brominated isobutylene-co-p-methyl styrene (BIMS) and its blends with EPDM [40]. Using the theoretical model of Tokita, they have tried to optimize the rmU parameters. They measured the critical nip-gap at which a front-to-back roll transition takes place. They concluded that addition of different fillers reduced the critical nip-gap for BIMS as compared to the gum polymer. The critical nip-gap is lower for systems containing... 

Isobutylene-based elastomers include HR, the copolymer of isobutylene and isoprene, halogenated HR, star-branched versions of these polymers, and the terpolymer isobutylene-p-methylene styrene-bromo-p-methyl styrene (BIMS). A number of recent reviews on isobutylene-based elastomers are available [33-35]. 

A useful application in the manufacture of ion-exchange resins may well be possible which avoids the use of carcinogenic chloromethyl ether. Here, a polymer of p-methyl styrene is chlorinated on the side chain with aqueous NaOCl and a phase-transfer catalyst. Sasson et al. (1986) have shown how stubborn . substituted aromatics like nitro/chlorotoluenes can be oxidized to the corresponding acids by using aqueous NaOCl containing Ru based catalyst. 

Very well defined block copolymers of styrene, p-methyl styrene, p-tert-butyl styrene and PSX were prepared, as judged by GPC, with molecular weights of over 100,000 g/mole. 

ESCA analysis showed a similar trend of incomplete surface coverage for the IK systems. Also, no domains were visible in any of the IK styrenic graft systems by TEM. There is an expected trend with respect to solubility parameter, p(t-butyl styrene) (6 s 8.1) has a solubility parameter much closer to that of polydimethylsiloxane (S a 7.3) than does p(p-methyl styrene) which is closer than p(styrene) (S s 9.1). 

Ligand 55c is also efficient in the cyclopropanation of other alkenes. 1,1 -Disub-stituted alkenes afford cyclopropanes in high enantioselectivity with ethyl diazoacetate as carbenoid source, Eq. 25 (34). Internal dissymetric trans alkenes are also excellent substrates. trans-P-Methyl styrene afforded a 95 5 diastereomeric mixture with cyclopropane 56a predominating in 96% ee, when the butylated hydroxy toluene (BHT) diazoester was used, Eq. 26 (35). 

Japanese investigators reported that liquid sulfur dioxide polymerizes styrene derivatives (e.g., p-methyl styrene, a-methyl styrene) (19). Unfortunately, the experiments were not executed under rigorously anhydrous conditions (high vacuum) so that the possibility for proton (e.g., sulfurous or sulfuric acid) initiation exists although the authors seem to believe that S02 is the catalyst, probably by the following process 2S0a SO2 +SO e. The cationic nature of the mechanisms was proven by the facts that no polysulfones formed, that the polymerization was inhibited by bases, and that free radical inhibitors did not affect the reaction. These authors also claim that formaldehyde is polymerized by sulfur dioxide to a product which does not contain sulfur and whose infrared spectrum closely resembles that of a low temperature sample. 

Methyl hydrazine Methyl isobutyl ketone Methyl isobutyrate Methyl, mercaptan Methyl methacrylate 1 -Methylnaphthalene 2-Methyl-2-propanethiol, see t-Butyl mercaptan Methyl-n-Propyl ketone 1 -Methylpyrrole Methyl salicylate a-Methyl styrene m.-p-Methyl styrene Methyl sulphate, see Dimethyl sulphate... 

PENTYL-PROPYL-SULFIDE 1-OCTANETHIOL BUTY-DISULFIDE ALPHA-METHYLSTYRENE PROPENYL-BENZENE, CIS PROPENYL-BENZENE, TRANS M-METHYL-STYRENE 0-METHYL-STYRENE P-METHYL-STYRENE PROPYLBENZENE CUMENE... 

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