Cellulose esterified with low molecular weight PBT and its composites with PBAT

Low molecular weight oligomer polybutylene terephthalate (PBT) with carboxyl terminated groups was synthesized via dry esterification method, and then was used to esterify the surface of cellulose. The optimal esterification reaction conditions were identified as a PBT-to-cellulose mass ratio of 1:5, an esterification time of 6 h, and a catalyst dosage of 2% of the cellulose mass. The esterified cellulose was blended with PBAT to prepare composite materials, and the effects of varying amounts of esterified cellulose on the mechanical properties, thermal properties, and two-phase compatibility of the composites were explored. The performance of PBAT/esterified cellulose composites was then compared with that of PBAT/cellulose composites. The results indicated that the compatibility of cellulose with PBAT and its dispersion in PBAT were significantly improved after PBT esterification. When the ratio of PBAT/esterified cellulose was 95/5, the tensile strength, elongation at break and tensile modulus of the composite material reached 21.89 MPa, 593.82% and 86.3 MPa, respectively.