Intellectual Property Office

Non-Confidential Disclosures

“Fluoropolymer/Clay Nanocomposites with Exfoliated Structure”

PSU Invention Disclosure No. 3173

Key Words:

Functional fluoropolymers; polymer/clay nanocomposites; interfacial compatibilizer; polymer surfactant

Links:

http://www.matse.psu.edu/fac/profiles/chung.htm http://www.ipo.psu.edu

Inventors:

T.C. (Mike) Chung, Q.M. Zhang, Y. Lu, J. Claude

Background:

Fluoropolymers, including Teflon® and PVDF, exhibit a unique combination of properties, such as thermal stability, chemical inertness (acid and oxidation resistances), low water and solvent absorptivities, self-extinguishing, excellent weatherability, and very interesting surface properties. They are commonly used in many high-end applications, such as aerospace, automotive, textile finishing, and microelectronics. However, these fluoropolymers also have some drawbacks, including poor adhesion to substrates, lack of crosslinking chemistry, and inertia to chemical modifications, which limit their applications in situations where interactive and reactive properties are paramount.

Invention description:

This invention discloses a new functionalization technology to prepare functional fluoropolymers that contain one or two terminal functional groups at the polymer chain end(s), which are very reactive in many chemical reactions and exhibit distinctive interfacial interactive properties with many organic and inorganic materials. One targeted application is the formation of fluoropolymer/clay nanocomposites with exfoliated structure. The chain end functionalized fluoropolymer contains an unperturbed hydrophobic and oleophobic fluoro-polymer chain and a terminal functional group, such as Si(R)n(OH)3-n, Si(R)n(OR)3-n, OH, NH2, COOH, anhydride, ammonium, immidazolium, sulfonium, phosphonium ions, etc., in one or both polymer chain ends (Fig. 1). The terminal functional group can anchor the fluoropolymer chain to clay surfaces between interlayers, either by chemical bond (such as Si-O-Si bond), strong interaction (such as hydrogen bonding and ion-ion interaction) or ion-exchange with cations (Li+, Na+, Ca2+, W, etc.) located on the surfaces between the clay interlayers. The main part of the chain, the unperturbed high molecular weight hydrophoblic and oleophobic fluoropolymer chain, dislikes hydrophilic clay surfaces and thus exfoliates the clay layer structure. This disordered clay structure is maintained even after further mixing with neat (unfunctionalized) polymer that is compatible with the backbone of the chain end functionalized fluoropolymer.

Advantages:

• Fluoropolymer/clay nanocomposites with exfoliated structure
  
• Exhibit desirable interfacial interactive properties with many organic and inorganic materials
  
• Maintains disordered state even after mixing with unfunctionalized polymer
• Pretreating clay material with organic surfactant or acids is not needed
• Can be prepared by: (i) in situ polymerization, (ii) melt blending, or (iii) solution blending
  

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