Poly(l-lactic acid) (PLLA) chains were grafted on xyloglucan substrates via ring-opening polymerization
of the l-lactide monomer. Different parameters such as the nature of the substrate (native or modified
xyloglucan) and the substrate/monomer ratios were varied in the synthesis to achieve different lengths
of the grafted chains. A range of experimental techniques including infrared spectroscopy and nuclear
magnetic resonance were used to characterize the final product. Thermal analysis showed that the glass
transition temperature of xyloglucan was decreased from 252 ◦C to 216 ◦C following the grafting of PLLA.
The grafting of less hydrophilic chains from xyloglucan also affected the interaction with water: the
PLLA-grafted xyloglucan was insoluble in water and the moisture uptake could be decreased by about 30%.
Xyloglucan adsorbs strongly to cellulose; therefore such a graft copolymer may improve the compatibility
between cellulose fibers and PLLA. The PLLA-grafted xyloglucan may be useful as a novel compatibilizer
in fiber-reinforced PLLA composites