Title : Significantly tunable foaming behavior of blowing agent for polyethylene foam resin with a unique designed blowing agent system
Abstract:
The chemical blowing agent plays a crucial role in enhancing the performance of polyethylene (PE) foaming resin during the rotational foaming process. Previously, the conventional blowing agent of PE resin commonly used pure azodicarbonamide (AZ). It had the unavoidable drawbacks of releasing NH3 and exhibiting strong reactions during the rotational foaming process. Meantime, pure AZ had a relatively high decomposition temperature resulting in a sharp foaming process. To address the above issues, this work developed a unique designed blowing agent system. In this study, a novel blowing agent for PE resin was successfully synthesized by one-pot method. This blowing agent consisted of an activator and AZ, which exhibited a lower decomposition temperature and a milder decomposition rate than AZ. The activator was constituted of small-sized ammonium dihydrogen phosphate on AZ surface, which could be decomposed properly and deliver phosphoric acid and H2O during the foaming process. Then AZ reacted with H2O under phosphoric acid catalysis. And this reaction generated CO2 emission while reducing the emission of NH3 through recombination with phosphoric acid. Moreover, phosphoric acid catalysis caused a decrease in AZ decomposition temperature. Meantime, the thermal coupling appeared during the foaming process, which could further reduce the decomposition rate. Consequently, the small-sized activator played a key role in regulating cell formation and diffusion. Compared to AZ, the novel blowing agent system significantly reduced the cell diameter of PE foam resin and enhanced its flexural modulus by 50%. Furthermore, the novel blowing agent facilitated better demolding performance and improved surface morphology of PE foam product. This research provides a significant foaming behavior regulation for PE resin during industrial applications.
Audience Take Away Notes:
- Introduce our new creativity strategy
- Preparation and characterization of PAZ
- Thermal decomposition performance of PAZ
- Property of PE foaming product
- The mechanism of foaming behavior for PAZ
