Styrenes GENERAL INDEX

In general, the multiphasic heterogenous nature of the impact grade styrene-based polymers is the root cause of their opaque-turbid nature. In determining the transparency of the blends, size and the size-distribution pattern of the dispersed phase along with the refractive index difference between the continuous and the dispersed phases are two very important criterion [133]. 

Clarity of Graft Polymers with Varying Methyl Methacrylate/ Styrene Ratios. Refractive index considerations 7,8) and general state of the art considerations (8) favor methyl methacrylate (MMA) over styrene (St) as the major monomer portion of the matrix. With this in mind, we selected MMA/St ratios from 62/38 to 80/20 (wt %). Using a commercial Firestone butadiene latex (2004) to supply the 15% rubber graft, polymerization runs were made as outlined in Table I. 

Fig. 12. General effect of increasing styrene or vinyl concentrations in solution SBRs on abrasion index, processability and wet traction. Reproduced with permission from Rubber Industry.

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