Styrene random

Use of these polar randomizers also increases the vinyl unsaturation in the copolymer. Butadiene-styrene random copolymers can also be prepared by a very slow and continuous addition of monomers22. or by an incremental addition of butadiene to a styrene-rich monomer mixture during polymerization. These two... 

EVALUATION OF ALKYLLITHIUM INITIATED BUTADIENE-STYRENE RANDOM COPOLYMER (SOLPREN 1204) IN COMPOUNDED STOCK... 

The JG and the a-Relaxations of Poly(n-butyl methacrylate) in Poly(n-butyl-methacrylate-stat-styrene) Random Copolymers. The copolymers of poly(n-butyl methacrylate) (PwBMA) and polystyrene (PS) is one example [338,339]. Here PnBMA is the lower Tg component A. Neat PnBMA has n = 0.47 and a JG relaxation. On increasing the styrene content from 0 to 66 mol% in the copolymer, a monotonic increase of nA of the PnBMA component leads to a concomitant increase in the separation of the JG relaxation from the segmental relaxation, both of the PwBMA component. This changes were observed in the dielectric relaxation experiment. 

Figure 2. Effects of ozone exposure on critical surface energy. Exposure curve units are ppm-min. Key , butadiene o, crosslinked butadiene and+, 75/25 butadiene/styrene random copolymer.

The characteristics of the samples used are summarized in Table 1 where SBR, PB and PI designate, respectively, a random copolymer of poly(styrene-random-butadiene), polybutadiene, and polyisoprene. Binary mixtures of PP/EPR (14), X-7G/PET (15), both having (50/50 wt/wt composition), and PS/SB (16) (35/65 w wt) were occasionally us, where PP, EPR, X-7G, PET, PS and SB, designate, respectively, isotactic poly(propylene), a random copolymer of... 

It is worth noting that behavior of ethylene copolymers containing bulkier a-olefins is completely different from that of EP copolymers. In fact, bulkier comonomer units are excluded from the crystalline phase, which remains orthorhombic for high comonomer contents, giving rise only to small increases of the a and b unit cell parameters (as shown for ethylene/styrene random copolymers in Figure 12.10). Moreover, as shown in Figure 12.12, as the ethylene molar content in EP copolymers decreases, the concomitant decrease in crystallinity is less rapid for EP copolymers than for ethylene/styrene and similar ethylene copolymers containing bulkier a-olefins. This is due to the inclusion of propylene units and the exclusion of bulkier units from the crystalline phase. ... 

The effects of copolymerization vary from one system to another but a large number of copolymer rubbers obey the Gordon-Taylor relation quite closely. In effect this proposes that the T, of a copolymer can be linearly interpolated from the TgS of the appropriate homopolymers. Butadiene-styrene random copolymers provide a very good fit but in general interactions between the... 

Fig. 3.27 Change of concentration of (1) poly(methyl methacrylate) radicals and (2) polystyrene radicals with time at 65°C for methyl methacrylate-styrene random copolymer having a weight ratio of A/S = 4/1 [11],...

HDPE -I- polystyrene and LDPE + polystyrene were compatibilized by adding ethylene/styrene random copolymers, which were semimiscible in the polyethylene phase. They decreased domain size and increased interfacial adhesion, ultimate elongation, and tensile toughness. Increasing their molecular weight also increased toughness [59]. 

Hyun, J., Han, J., Ryu, C.Y., and Interrante, L.V. (2006) Synthesis of cycloUnear poly(caibosilane)-g-poly(methyl methacrylate or styrene) random copolymers. Macromolecules, 39,8684—8691. 

In addition, there have been a number of studies of the steady state fluorescence properties of styrene random copolymers in dilute solution as a function of copol3nner composition [57-60] In these studies, the conclusion that energy migration is important in PS has generally been reached based on correlations between the ratio of excimer-to-monomer fluorescence and various parameters that describe copolymer composition ... 

W01 Wohlfarth, Ch., Isopiestic vapor sorption measurements for solutions of hutadiene/styrene random copolymer in cyclohexane, benzene, toluene, ethylbenzene, 1,4-dimethylbenzene, or 1,3,5-trimethylbenzene at (343.15 - 398.15) K, ELDATA Int. Electron. J. Phys.-Chem. Data, 2, 13, 1996. 

W02 Wohlfarth, Ch., Isopiestic vapor sorption measurements for solutions of acrylonitrile/ styrene random copolymer in benzene, toluene, 1,2-dimethylbenzene, 1,3-dimethylbenzene,... 

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