Starch/poly (butyl Diacid Butyl Glycol Ester Preparation Of Complete Biodegradable Plastics, And The Application Research Of Rare Earth Photosensitizer

This thesis is aiming at developing a biodegradable plastic and studying thesynthesis of rare earth photosensitizer with carboxylic acid and modification of starch,and blending them with poly butylene succinate (PBS) to prepare a new polymerdegradation material.Under different pH conditions, a series of cerium phthalate complexes weresynthesized which were used as photosensitizers to degrade macromolecular materials.The membrane was prepared by dissolving of PBS. The rare earth photosensitizer withcarboxylic acid was characterized via ultra-violet light, natural light exposure, soilburial and a variety of analytical characterization methods to select the pH with the bestUV absorption and best photosensitizer content.The mechanical properties of PBS were modified by adding different plasticizersthermoplastic starch (TPS), and dimethyl sulfoxide (DMSO) was selected as aplasticizer to improve the plasticity of the acetic acid ester starch due to its strongmolecular association, and a new type of biodegradable polymer material was preparedwith the PBS modified by TPS.The effect of DMSO, TPS, coupling agent and photosensitizer on the performanceof the TPS/PBS material was tested by X-ray diffraction, infrared spectroscopy,differential scanning calorimetry, scanning electron microscopy. Mechanical properties,rheological properties and biological degradation were determined.The experimental results showed that: the modified material had the best tensilestrength when the content of DMSO was10%, elongation at break was maximum with20%of the DMSO; elongation at break was maximum with20%of the TPS; andcoupling agent increased the compatibility of TPS and PBS, which increased the toughness and the mechanical performance of the materials to meet the applicationrequirements. After180days being buried in the soil, TPS/PBS with rare earthphotosensitizer showed a large number of mildew and performance degradation andfragmentation on the surface, with material weight loss being50.28%, which indicatedmaterial degradation in a short period of time. Scanning electron microscopy revealedthe uneven distribution of material and full of holes and cracks, and the interfaceshowed non-flat and non-continuous phase. The structural damage was obvious and itachieved the purpose of degradation.