Intellectual Property Office

Non-Confidential Disclosures

“Maleic Anhydride Modified Polyolefins for Improving Polyolefin Blends and Composites”

PSU Invention Disclosure No. 2464

Key Words:

Maleic anhydride, functionalized polyolefin

Links:

US Patent 6,699,949
http://www.matse.psu.edu/fac/profiles/chung.htm
http://www.ipo.psu.edu

Inventor:

T.C. (Mike) Chung,

Background:

Although useful in many commercial applications, polyolefins suffer a major deficiency in that they interact poorly with other materials. Their inert nature significantly limits their end uses, particularly those in which adhesion, dyeability, paintability, or compatibility with other materials is paramount. Functionalizing by the addition of polar groups can improve their adhesion to many substrates. Maleic anhydride (MA) modified polyolefins are the most important class of functionalized polyolefins in commercial applications due to their unique combination of low cost, high activity and good processiblity. MA modified polypropylene (PP-MA) is the most investigated polymer and is used in applications, such as glass fiber reinforced PP, anticorrosive coatings for metal pipes and containers, multilayer sheets of paper for chemical and food packaging, and polymer blends. PP-MA polymer is usually prepared by high temperature chemical modification of pre-formed PP under free radical conditions using thermally decomposed organic peroxides. Due to the inert nature of the PP structure and poor control of the free radical reaction, this process results in many undesirable side reactions.

Invention description:

The process is a post-reactor solution process for grafting maleic anhydride (MA) molecules to polyolefin with controllable polymer structure and with little or no side reactions. The chemistry involves an in situ controlled oxidation reaction of trialkylborane (BR3) in the presence of polyolefin (e.g., polyethylene (PE), polypropylene (PP), ethylene-propylene copolymer (EP), etc.) and MA. Under certain reaction conditions, this process produces very desirable mono-oxidized trialkylborane adducts that can undergo homolytic cleavage to form [R--O* *O--BR2] and activate the saturated polyolefin chain by alkoxyl radical hydrogen abstraction at ambient temperature. The formed polymeric radical associated with the oxidized borane moiety (Fig 1), then reacts with MA by addition reaction without side reactions. The resulting functional polyolefins are very effective interfacial materials for improving the interaction between polyolefins and other materials, such as glass fiber, nano-size clay particles, fillers, nylon, etc., in polyolefin blends and composites.

Advantages:

• Maleic anhydride modified polyolefin with controlled molecular weight and MA content.
  
• Maleic anhydride grafting is done at ambient temperature and with little or no side reactions.
  
• Improves the interaction between polyolefins and other materials, such as glass fiber, nano-size clay particles, fillers, nylon, etc., in polyolefin blends and composites.
  

Contact:

Bradley A. Swope
Sr. Technology Licensing Officer
The Pennsylvania State University
113 Technology Center
University Park, PA 16802
Phone: (814) 863-5987
Fax: (814) 865-3591
E-mail: bradswope@psu.edu