Abstract: The present application discloses a continuous dynamic and efficient devolatilization method for a polymer/volatile system based on high mass transfer interfaces, including the following steps: providing a dynamic single-screw devolatilizer, feeding a polymer solution to the devolatilizer, wherein the polymer solution includes polymer and volatile substances with small molecule weight, and the volatile substances include organic solvents, residual monomers, water or reaction by-products; conveying and compressing polymer materials by the screw downstream a devolatilization section, and extruding the polymer materials out of the dynamic single-screw devolatilizer directly; or providing a side-feeding extruder downstream of the devolatilization section and feeding plastic additives into a devolatilized polymer melt, and then melt blending the plastic additives with the devolatilized polymer melt at an end of the dynamic single-screw devolatilizer before exiting the dynamic single-screw devolatilizer.

Abstract: The present application discloses a biodegradable polymer expended bead capable of being formed by steam compression molding, including the following components in parts by weight: 10-88 parts of PBS, 10-88 parts of PLA, 1-4 parts of a chain extender masterbatch, 1-3 parts of a nucleating agent masterbatch and 5-12 parts of a supercritical CO2 foaming agent; wherein a concentration of optical isomer D-lactic acid monomer in a molecular chain of the PLA is 2-8%. The present application uses PBS and PLA as polymer matrixes, with an addition of a chain extender and a nucleating agent. The chain extender undergoes a chain extension reaction and a branching reaction with reactive end groups of PLA and PBS. The expended bead has good heat resistance, and can be formed using steam compression molding to obtain a steam compression molded product with good adhesion between beads and stable size.