Grafting PEG on cellulose nanocrystals via polydopamine chemistry and the effects of PEG graft length on the mechanical performance of composite film

Ting Zheng; Craig M Clemons; Srikanth Pilla

doi:10.1016/j.carbpol.2021.118405

Grafting PEG on cellulose nanocrystals via polydopamine chemistry and the effects of PEG graft length on the mechanical performance of composite film

Carbohydr Polym. 2021 Nov 1:271:118405. doi: 10.1016/j.carbpol.2021.118405. Epub 2021 Jul 10.

Authors

Ting Zheng¹, Craig M Clemons², Srikanth Pilla³

Affiliations

¹ Department of Automotive Engineering, Clemson University, Greenville, SC 29607, United States; Clemson Composites Center, Clemson University, Greenville, SC 29607, United States.
² Department of Automotive Engineering, Clemson University, Greenville, SC 29607, United States; USDA Forest Service, Forest Products Laboratory, Madison, WI 53726, United States.
³ Department of Automotive Engineering, Clemson University, Greenville, SC 29607, United States; Clemson Composites Center, Clemson University, Greenville, SC 29607, United States; Department of Material Science and Engineering, Clemson University, Clemson, SC 29632, United States; Department of Mechanical Engineering, Clemson University, Clemson, SC 29632, United States. Electronic address: spilla@clemson.edu.

PMID: 34364549
DOI: 10.1016/j.carbpol.2021.118405

Abstract

In this study, cellulose nanocrystals (CNCs) with PEG grafts of various lengths (1 k, 2 k, 5 k, and 10 kDa) were prepared via a polydopamine (PDA) mediated method in the aqueous solution. The prepared CNC-PEGs were further used to reinforce the polyvinyl alcohol (PVA) at the loading of 0, 1, 3, 5, and 7 wt% in order to demonstrate the effects of the PEG length on the properties of the PVA/CNC nanocomposites. PEG surface modification resulted in simultaneous improvements in stiffness and toughness. The graft lengths have noticeable impacts on the properties of composites. The shorter graft yields better enhancement in strength and stiffness, attributable to the high efficiency in the stress transfer and high interface adhesion. The longer PEG graft length yields high graft-matrix entanglement, forming a thicker rubbery coating layer that enhances the toughness of PVA/CNC composites.

Keywords: Cellulose; Graft length; Nanocrystal; Natural fibre composites; Polydopamine.

MeSH terms

Cellulose / chemistry*
Elastic Modulus
Indoles / chemistry
Membranes, Artificial*
Molecular Structure
Nanocomposites / chemistry*
Nanoparticles / chemistry*
Polyethylene Glycols / chemistry*
Polymers / chemistry
Polyvinyl Alcohol / chemistry
Tensile Strength

Substances

Indoles
Membranes, Artificial
Polymers
polydopamine
Polyethylene Glycols
Polyvinyl Alcohol
Cellulose