Abstract: Propylene random copolymer compositions are described herein. The compositions generally include a propylene random copolymer including from about 95.0 wt. % to about 99.0 wt. % propylene and from about 0.2 wt. % to about 0.8 wt. % ethylene, an additive selected from clarifiers, nucleators and combinations thereof and a stabilizer, wherein the propylene random copolymer exhibits a melt flow rate of from about 0.5 g/10 min. to about 4.0 g/10 min., a molecular weight distribution of from 5 to 10 and wherein the propylene random copolymer composition exhibits a flexural modulus of from about 180,000 psi to about 260,000 psi.

Abstract: The selection of additives to improve the solubility of blowing agents may be facilitated by using a method that involves determining and comparing the activity coefficients of prospective additives to the activity coefficients of candidate blowing agents in a given base polymer for producing a polymeric foam article. The method for the selection of an additive may comprise selecting a representative compound for the base polymer and determining a first activity coefficient for a blowing agent in the representative compound. Also selected are several candidate additives, each having a different functional group, and determining a second activity coefficient for the blowing agent in each of the candidate additives. Among the candidate additives is selected the additive, wherein the second activity coefficient is lower than the first activity coefficient. The method may be incorporated into a process for forming polymeric foams and the manufacture of a polymeric foam.

Abstract: The invention provides a polymerization process with improved catalyst activity of a metallocene catalyst supported on silica treated with MAO, a process for supporting a metallocene compound on silica treated with MAO, a metallocene catalyst supported on silica treated with MAO within a certain temperature range and a process for making a metallocene catalyst supported on silica treated with MAO. The invention includes supporting the metallocene compound on a MAO-treated silica at a temperature of below 0° C. The supported catalyst is activated with an aluminum alkyl. The catalyst may be prepolymerized in a tubular reactor prior to being introduced into the polymerization reaction zone.