Effects of carboxymethyl cellulose concentration on mechanical, viscoelastic properties, and thermal properties of starch/plant fiber foaming tableware materials with foam structure

In this study, a novel bio-based composite of starch/plant fiber foaming tableware material was prepared by the hot-pressing foaming method. The influence of the content of carboxymethyl cellulos (CMC) as a new type of film-forming agent filler on the properties of foam materials was systematically investigated. The results showed that the foam material with 10 wt% CMC had excellent cell morphology and uniform cell size (the average cell size reached the minimum value of 465.7 μm), relatively high porosity (57.01%), and excellent thermal insulation properties (thermal conductivity: 0.0541 W/m·K). The tensile strength of foam increased from 4.289 MPa for 0 wt% CMC to 5.714 MPa for 10 wt% CMC loading. Similarly, the flexural strength also increased from 11.609 MPa to 15.719 MPa for the foam material with 10 wt% CMC. The thermal stability and viscoelastic properties of the foam material reached the highest after adding 10 wt% CMC. In addition, the increase of CMC content is beneficial to improve the oil resistance and biodegradability of the material. The research shows that CMC is an effective filler to improve the properties of starch/plant fiber foaming tableware materials, which can greatly promote the development of bio-based polymer foam materials.