Surface chain engineering of chitin nanocrystals towards tailoring the nucleating capacities for poly(β-hydroxybutyrate)

Chitin nanocrystal (ChNC) is good nucleation agent for aliphatic polyesters because of its high-energy surface. To moderate its nucleation activity, silane coupling agents with different chain lengths or functional groups were used to modify ChNCs in this work, and biodegradable poly(beta-hydroxybutyrate) (PHB) was used as target polymer for crystallization study. Surface coupling of ChNCs improves their phase adhesion to PHB chain and weakens their nucleation act ivi ties. The alterations strongly depend on the surface chain structure of ChNCs: sulfhydryl silane-coupled ChNC shows lowered nucleation activity, whereas amino silane-coupled ChNCs even become antinucleation agents. The interfacial compatibility is vital to altered role of ChNCs and to following changes in spherulite growth and ring-banded morphology, which is further disclosed using Flory Huggins interaction parameters and rheological responses as probes. This work provides useful information on tailoring the functions of ChNCs as nanoadditive for biodegradable aliphatic polyesters by the way of surface chain engineering. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The surface modification of Chitin nanocrystal (ChNC) with silane coupling agents of different chain structures can effectively alter its nucleation activity, leading to changes in its compatibility with PHB and spherulite growth morphology. Understanding the interfacial interactions between ChNC and PHB is crucial for tailoring ChNC as a nanoadditive for biodegradable aliphatic polyesters.