Abstract: A method and apparatus are disclosed for purifying copolymer compounds having monovinyl aromatic blocks and conjugated diene blocks by reducing the residual monomer content of the finished polymer. The method and apparatus includes a combination of heat exchangers and devolatilizers used in conjunction with a copolymerization reactor system.

Abstract: Polymerization processes in a bulk loop reactor are described herein. In particular, a method of contacting a flow of metallocene with a flow of propylene is provided. This method includes directing the flow of metallocene towards a junction, directing the flow of propylene towards the junction and maintaining a portion of the flow of metallocene separate from a portion of the flow propylene within a portion of the junction downstream of the flow of propylene into the junction. In another embodiment, a method of introducing a quantity of antifouling agent into a catalyst mixing system is provided. In this embodiment a portion of the antifouling agent is introduced at or downstream of a point of contact of a stream of propylene with a stream of catalyst. The antifouling agent may be a member, alone or in combination with other members, selected from Stadis 450 Conductivity Improver, Synperonic antifouling agent, and Pluronic antifouling agent.

Abstract: The present invention relates to propylene polymerization process in a bulk loop reactor, and particularly to propylene polymerization process for polymerizing commercial quantities of polypropylene in a bulk loop reactor by sequentially introducing Ziegler-Natta and metallocene catalyst systems into the bulk loop reactor.

Abstract: The present invention relates to propylene polymerization process in a bulk loop reactor, and particularly to propylene polymerization process for polymerizing commercial quantities of polypropylene in a bulk loop reactor by sequentially introducing Ziegler-Natta and metallocene catalyst systems into the bulk loop reactor. In one embodiment, separate catalyst mixing systems are used to introduce a quantity of metallocene catalyst and Ziegler-Natta catalyst into the bulk loop reactor. The frequency rate at which the quantity of metallocene catalyst is introduced into the bulk loop reactor may be higher than the frequency rate at which the quantity of Ziegler-Natta catalyst is introduced.

Abstract: Polypropylene heterophasic copolymers are produced having increased impact strength through the use of controlled rheology techniques by the addition of a peroxide at conditions which increase the deactivation or half life of the peroxide. The increased half life slows down the vis-breaking process and allows better dispersion of rubber particles within the polymer. In this way, copolymers having a high melt flow can be prepared while obtaining high impact strength and lower stiffness values, without the need for additional elastomeric modifiers.

Abstract: Polypropylene heterophasic copolymers are produced having increased impact strength through the use of controlled rheology techniques by the addition of a peroxide at conditions which increase the deactivation or half life of the peroxide. The increased half life slows down the vis-breaking process and allows better dispersion of rubber particles within the polymer. In this way, copolymers having a high melt flow can be prepared while obtaining high impact strength and lower stiffness values, without the need for additional elastomeric modifiers.

Abstract: Polypropylene heterophasic copolymers are produced having increased impact strength through the use of controlled rheology techniques by the addition of a peroxide at conditions which increase the deactivation or half life of the peroxide. The increased half life slows down the vis-breaking process and allows better dispersion of rubber particles within the polymer. In this way, copolymers having a high melt flow can be prepared while obtaining high impact strength and lower stiffness values, without the need for additional elastomeric modifiers.

Abstract: The present invention relates to propylene polymerization process in a bulk loop reactor, and particularly to propylene polymerization process for polymerizing commercial quantities of polypropylene in a bulk loop reactor by sequentially introducing Ziegler-Natta and metallocene catalyst systems into the bulk loop reactor. In one embodiment, separate catalyst mixing systems are used to introduce a quantity of metallocene catalyst and Ziegler-Natta catalyst into the bulk loop reactor. The frequency rate at which the quantity of metallocene catalyst is introduced into the bulk loop reactor may be higher than the frequency rate at which the quantity of Ziegler-Natta catalyst is introduced.

Abstract: Polypropylene heterophasic copolymers are produced having increased impact strength through the use of controlled rheology techniques by the addition of a peroxide at conditions which increase the deactivation or half life of the peroxide. The increased half life slows down the vis-breaking process and allows better dispersion of rubber particles within the polymer. In this way, copolymers having a high melt flow can be prepared while obtaining high impact strength and lower stiffness values, without the need for additional elastomeric modifiers.

Abstract: Coupling of block base copolymers terminated by a lithium atom of the typical formula S-B-Li, in which S is a monovinylaromatic hydrocarbon block and B is a conjugated diene block, by the use of at least one difunctional deactivating coupling agent and at least one polyfunctional deactivating coupling agent in a molar ratio such that the linear polymer obtained by coupling represents 65 to 95% by weight of the total polymer material obtained by coupling.

Abstract: Transparent linear resinous conjugated diene/monovinyl-substituted aromatic block copolymers of improved properties are prepared by forming a monovinyl-substituted aromatic homopolymer block referred to as S.sub.1, followed by forming a conjugated diene homopolymer block, referred to as B.sub.1 and linked to segments S.sub.1, followed by the formation of a conjugated diene/monovinyl-substituted aromatic random copolymer block, referred to as B/S and linked to segment B.sub.1, followed by the formation of a monovinyl-substituted aromatic homopolymer block, referred to as S.sub.2 and linked to segment B/S thereby forming the block copolymer S.sub.1 -B.sub.1 -B/S-S.sub.2 wherein the molecular weight of the S.sub.2 block is significantly greater than the molecular weight of the S.sub.1 block.