CaCO(3) blowing agent mixing method for biomass composites improved buffer packaging performance

Biodegradable composites with an open-cell structure were developed to replace petroleum-based buffer packaging materials. To overcome the problem of uneven and insufficient foam in the composites, CaCO(3) was used as a nucleating agent to prepare porous composites. At 5 wt% CaCO(3), more uniform and dense composite cells with better cushioning performance were obtained. A further increase in the CaCO(3) content caused the density of the cells and the cushioning properties of the composites to decrease. The addition of CaCO(3) improved the thermal stability and water barrier properties. The moisture absorption was reduced by 15%. X-ray diffraction analysis indicated that the addition of CaCO(3) destroyed the crystalline structure of the starch and produced a new crystalline peak, resulting in a significant reduction in the crystallinity. The decrease in the crystallinity of the starch resulted in the formation of a homogeneous slurry that produced a uniform foam in the composites.