Surface Modification of Cellulose Nanocrystals

Poster Session: 

B

Presenter: 

Huyen Vu

Authors: 

Huyen Vu, E. Bryan Coughlin

Author Affiliation: 

University of Massachusetts Amherst

Abstract: 

Cellulose is an abundant resource that is renewable and biodegradable. Specifically, cellulose nanocrystals (CNCs) have high toughness which make them ideal for use in composite applications to strengthen polymer matrices. Understanding the fundamental structure-property relationships of the interphase and its effect on macroscopic properties will allow for the design of improved multi-functional composites. Surface-modified CNCs are being prepared to then be incorporated into polymer matrices. Using an ATRP “grafting from” approach will allow high grafting density on CNC, avoiding steric hindrance issues that are often associated with a “grafting to” method. An ATRP initiator was first attached to CNC followed by polymerization of water soluble monomers, diethylene glycol methacrylate (MEO2MA) and poly(oligo(ethylene glycol) methacrylate) (OEGMA). Thermogravimetric analysis (TGA) was used to estimate the efficiency of the grafted P(MEO2MA-ran¬-OEGMA). Since PMEO2MA and POEGMA300 have LCST value of 26 oC and 60-64 oC, respectively, graft composition variation was achieved by comonomer feed ratio adjustment resulting in tunable cloud points between 26-64 oC. Solubility of grafted CNCs in non-polar solvents was improved in THF and toluene. Current work focuses on chain extension of MMA on grafted CNC to allow for dispersion in polymer matrices.