Semi-IPN of biopolyurethane, benzyl starch, and cellulose nanofibers: Structure, thermal and mechanical properties

摘要

The aim of this study was to develop bionanocomposites of biopolyurethane (PU), benzyl starch (BS), and cellulose nanofibers (CNF) with semi-interpenetrating polymer network (S-IPN) structure of improved properties. Morphology, thermal and mechanical properties of S-IPN blends and nanocomposites were studied and compared with the neat polymers. Microscopy study showed that PU and BS were partially miscible as well as CNF were dispersed in both PU and BS phases in the nanocomposites. Dynamic mechanic thermal analysis demonstrated that BS decreased the tan d peak of the PU while CNF increased it. The positive shifting of tan d peak in the S-IPN nanocomposite also indicated the presence of CNF in the PU phase. It was also noticed that SIPN nanocomposite displayed two tan d peaks at higher temperature, indicating molecular interaction among BS, PU, and CNF. Furthermore, the S-IPN nanocomposites displayed significantly higher E-modulus and tensile strength compared with the neat PU. (C) 2016 Wiley Periodicals, Inc.