PROGRESS: Completed Project	PROJECT REF: PA055
PROJECT TITLE: Stable Polymer Blends from a Two-Step Crosslinking Process
PROJECT DESCRIPTION: Polymer blending has great potential for the development of new materials with special properties for various applications. Successful polymer blending can also yield great ecological and economic advantages. The simple mechanical mixing or blending of two or more polymers results in poor mechanical properties because most polymers are incompatible. One of the most frequently used methods to compatibilize blends is the incorporation of a block copolymer. However, the costs of synthesizing the tailor-made compatibilizers make this route commercially unattractive. A simple, expedient, and reliable process for blending is needed. The invention provides an efficient and reliable method for blending polystyrene (PS), polyethylene (PE), and optionally, polypropylene. The method includes a sequential introduction of various components, the crosslinking of the various components with a cross-linking agent such as dicumyl peroxide (DCP). PE is first crosslinked in the melt at high temperature by using a small amount of DCP. The crosslinked PE is then melt-mixed with PS and styrene-butadiene-styrene (SBS) block copolymer. By controlling the processing parameters and procedures, the residual free radicals in PE will react with the butadiene component of SBS at the interface. This reaction will enhance the adhesion between PS and PE phases, leading to improve mechanical properties. The invention can be applied to other polymer blend systems that have one of these components and a compatibilizer that can be crosslinked with a curing agent. Potential Applications: - Recycling materials - Formulating new materials with superior properties Advantages over Present Technologies: 1. Produce materials with high impact strength 2. Cost effective to recycle plastics polymers such as polyethylene, polystyrene, and Polypropylene 3. The two-step crosslinking process is simple
FOCUS AREA(S): Nanotechnology and Advanced Materials
KEYWORDS: recyling material, new material, polymer, crosslinking
MODE OF COLLABORATION: Technology Licensing, Further R&D Collaboration
STATUS PATENT: Granted	PATENT NO: US6063867
ORGANIZATION: Hong Kong University of Science and Technology R and D Corporation Limited
CONTACT PERSON: Shirley Woo	EMAIL: cawoosw@ust.hk
TEL: (852)-23587918	FAX: (852)-23582751
WEBSITE: http://rdc.ust.hk/	DATE: 29/12/2004