Stable Polymer Blends from a Two-Step Crosslinking Process
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.
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
- Recycling materials
- Formulating new materials with superior properties
Patent Number: US6063867A
Application Number: US199822638A
Inventor: Wang, Zhi | Chan, Chi Ming | Shen, Jiarui
Priority Date: 12 Feb 1998
Priority Number: US6063867A
Application Date: 12 Feb 1998
Publication Date: 16 May 2000
IPC Current: C08L002304 | C08L005302 | C08L002506 | C08L005300
US Class: 525071 | 525099 | 525273 | 5253338 | 525387
Assignee Applicant: The Hong Kong University of Science & Technology
Title: Stable polymer blends from a two-step crosslinking process
Usefulness: Stable polymer blends from a two-step crosslinking process
Summary: Production of stable blends of polystyrene, polyethylene, and optionally polypropylene found in post-consumer waste streams.
Novelty: Production of stable crosslinked polymer blend(s), involves two-step crosslinking process of initially mixing dicumyl peroxide with polyolefin, then crosslinking polyolefin with added block copolymer
化工/材料
化工/材料應用
12 Feb 1998
US 6063867
TTC.PA.055
香港
