摘要
The expansion ratio, resilience rate, moisture-proof, complex dynamic viscosity and crystallization rate for scCO 2 -aid glutaraldehyde modified thermoplastic starch (SC a TSGA 1.6 ) foams were substantially improved by further modification with sodium hexametaphosphate (SHP) and/or nano-silica (nano-SiO 2 ) particles during their scCO 2 -assisted foaming processes. These properties of SHP modified SC a TSGA 1.6 (SC a TSGA 1.6 SHP b and SC 11 TSGA 1.6 SHP 4 SiO 2 c ) foams were further improved with increasing scCO 2 -pressures during their scCO 2 -assisted foaming processes. Extremely high expansion ratio of ~ 65 and high resilience rate of 77% of the most appropriate SC 11 TSGA 1.6 SHP 4 SiO 2 0.5 foam were originally prepared using scCO 2 -assisted foaming processes. The significantly enhanced reliance rate found for SC a TSGA 1.6 SHP b and SC 11 TSGA 1.6 SHP 4 SiO 2 c foams is attributed to the better resilience of the smaller cell structures. Moreover, reaction of phosphate groups of SHP with the moisture-sensitive O–H groups of starch did occur favorably, and substantially improved the moisture-proof and complex dynamic viscosity (or melt strength) during the scCO 2 -assisted modification processing of SC a TSGA 1.6 SHP b and SC 11 TSGA 1.6 SHP 4 SiO 2 c . Thermal analyses revealed that crystallization rates and crystallization onset temperatures for SC 11 TSGA 1.6 SHP 4 SiO 2 c were substantially improved by addition of nano-SiO 2 particles. This substantial increase in melt strength, higher dissolved CO 2 concentrations at larger scCO 2 -pressures and/or higher crystallization rates for SC a TSGA 1.6 SHP b and/or SC 11 TSGA 1.6 SHP 4 SiO 2 c are expected to considerably enhance their nucleation rate and stability of cell structures during their scCO 2 -aid foaming processes. Consequently, higher expansion ratio, cell density and better reliance rate was found after the scCO 2 -aid foaming processes of SC a TSGA 1.6 SHP b and SC 11 TSGA 1.6 SHP 4 SiO 2 c foams.
危险品化学品经营许可证（带存储）