Surface modification of cellulose nanocrystals by grafting with poly(lactic acid)

Abstract

The use of biopolymers obtained from renewable resources is currently growing and they have found unique applications as matrices and/or nanofillers in 'green' nanocomposites. Grafting of polymer chains to the surface of cellulose nanofillers was also studied to promote the dispersion of cellulose nanocrystals in hydrophobic polymer matrices. The aim of this study was to modify the surface of cellulose nanocrystals by grafting from L-lactide by ring-opening polymerization in order to improve the compatibility of nanocrystals and hydrophobic polymer matrices. The effectiveness of the grafting was evidenced by the long-term stability of a suspension of poly(lactic acid)-grafted cellulose nanocrystals in chloroform, by the presence of the carbonyl peak in modified samples determined by Fourier transform infrared spectroscopy and by the modification in C1s contributions observed by X-ray photoelectron spectroscopy. No modification in nanocrystal shape was observed in birefringence studies and transmission electron microscopy.

Effect of surface-grafted cellulose nanocrystals on the thermal and mechanical properties of PLLA based nanocomposites

“…The O-C=O/C ratio increased from 0.09 to 0.13, which suggests the addition of ester bonds onto the surface of the material. These results are in agreement with previous works[39][40][41].…”

One-Pot Water-Based Hydrophobic Surface Modification of Cellulose Nanocrystals Using Plant Polyphenols

“…The catalytic ring-opening polymerization from CNCs, using the surface hydroxyl groups as initiating sites, is the most common route for the synthesis of CNCs with grafted polyesters, such as the bio-based polylactic acid. [26][27][28][29] In addition, atom transfer radical polymerization has been extensively explored to synthesize welldefined polymers on CNC surfaces. [30][31][32][33][34] These grafting from approaches have yielded highly compatible CNCs with contact angles in the range of 62 to 94°; however, the pre-attachment of initiator, polymerization reactions themselves and the work-up/separation are lengthy.…”

Effect of pH on Gelling Performance and stability of HPAM/Cr3+ Weak Gel

“…Most of the present research focus on the gel system itself [2,3] . The study about the rule of influence of pH, especially how does pH change the stability of weak gel, is relatively less [4] . The gelling and stability performance relate directly to the efficiency and result of profile control.…”