Covalent Functionalization of Carbon Nanotubes With Diisocyanate for Polyurethane Nanocomposites

Published

February 1, 2007

Author(s)

Aline Granier, Tinh Nguyen, Naomi Eidelman, Jonathan W. Martin

Abstract

Carbon nanotubes (CNTs) have a wide range of potential applications due to their unique mechanical properties, high aspect ratios, and electronics structures. Many of these applications require good dispersion and chemical reactivity of CNTs in polymer matrices. For effective stress transfer in nanocomposites, chemical functionalization so that covalent bonds are formed between CNT and the polymer matrix is desired. This paper describes a novel method to covalently functionalize CNTs that bear terminated isocyanate (NCO) groups, which then react covalently with urethane resins and other molecules. NCO functionalization of CNTs (NCO-fCNTs) is desirable, because NCO is highly reactive with hydrogen-active groups, such as OH and NH. The first step is synthesis of COOH-terminated CNTs by oxidation of unmodified CNTs in HNO3. The recovered COOH-fCNTs are then reacted with a diisocyanate molecule (NCO--NCO) in which one NCO has a higher reactivity than the other. By controlling the reaction parameters such as catalyst, temperature, etc., the higher reactive NCO group is allowed to react with the COOH-fCNTs, while the less reactive NCO group is not consumed and available for further reactions. Both NCO-fSWCNTs and NCO-fMWCNTs have been prepared. FTIR and TGA (thermogravimetric) results clearly show that the functionalized CNTs bear a substantial amount of organic molecules and free NCO groups. The NCO-fCNTs have been shown to react readily with amines and polyols, and have been used for fabrication of PU nanocomposites.

Proceedings Title

Proceedings of the Adhesion Society Meeting | 2007 | ASM

Conference Dates

February 1, 2007

Conference Title

Adhesion Society Meeting

Pub Type

Conferences

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Keywords

building technology, CNT, functionalization, NCO, polymer nanocomposite, polyurethanes

Citation

Granier, A. , Nguyen, T. , Eidelman, N. and Martin, J. (2007), Covalent Functionalization of Carbon Nanotubes With Diisocyanate for Polyurethane Nanocomposites, Proceedings of the Adhesion Society Meeting | 2007 | ASM, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=860692 (Accessed December 26, 2024)