Biobased Polyamide 4,36 Thermoplastic Elastomer and its Cellulose Nanocomposites

The search for fossil fuel-based polymer alternatives has attracted significantattention over the past few decades. A biobased polyamide elastomer, namelyPA4,36, is synthesized through a facile polycondensation of fatty acid-basedmonomer and 1,4-butanediamine. The chemical structure and molecularweight distribution of the polymer are characterized by Fourier infraredspectroscopy and gel permeation chromatography. PA4,36 displays a mediumhardness (Shore A/Shore D = 97/50), a high stretchability (1116%), ease ofmelt processing, and hydrophobicity. The introduction of cellulosenanocrystals (CNCs) to the elastomer reduces the melting temperature andcrystallization temperature due to the disturbance of CNCs on polymercrystallization, and influences its thermal degradation. It improves the glasstransition temperature by up to 5.1 °C because of the restriction of themolecular mobility of the polymer by CNCs. It increases the storage modulussignificantly from 1.5 GPa at 25 °C for neat PA4,36, to up to 10.8 GPa for thenanocomposite with 10 wt.% CNCs. The biobased elastomer and its CNCnanocomposites can be promising alternatives to some fossil fuel-basedelastomers with medium hardness.