Water soluble lignin graft copolymer (LGC) was synthesized using oil palm empty fruit bunch (OPEFB)
fibre as a renewable biomass source. Initially, Kraft lignin (KL) was extracted by exploiting the OPEFB
fibre Kraft pulping residue. KL was grafted with acrylic acid (AA) by using p-toluenesulfonic acid (PTS)
as a catalyst in the condensation process via the bulk technique. The resulting copolymer was characterized
by a Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), thermogravimetry-
Fourier transform infrared (TG-FTIR) and carbon–hydrogen–nitrogen analyzer (CHN). The
FTIR spectrum of the product showed absorption due to the presence of ester bonds as a proof of grafting.
The DSC and TG-FTIR results showed significant improvements in the KL thermal properties at least
27.261% as well as a thermal degradation resistance. The elements percentages of KL compositions were
changed as shown by the CHN data. SEM micrographs illustrated the grafting reaction homogenizing the
KL morphological structure.