Microwave-Assistant Synthesis And Modification Of Hyperbranched Polyester And Application On Alkaline Hydrolysis Of Polyester

Hyperbranched polymer has a widespread potential application prospect, which is generally thought as the fourth polymer material after linear, branching and crossing linking polymer. It gradually becomes the hot research spots in the area of biological medical material, nonlinear optics material, solids surface modification, ultra molecular chemistry, nanomaterials and so on. As a member of hyperbranched polymer, hyperbranched polyester has been commercialized. However, research on relevant structure or performance was less due to insufficient characterization method. Moreover, synthesis processing is also quite tedious. This study synthesized the hyperbranched polyester based on the microwave-assissted method by using pentaerythritol or trimethylolpropane as nuclear unit,2,2-dimethylol propionic acid or2,2-bis(hydroxymethyl)butyric acid as branching unit, and p-toluenesulfonic acid as catalyst. The products were characterized by determinating hydroxyl value with NMR and gelatin seepage chromatograph (GPC). The influence of monomer structure, reaction time, catalyst amount on the degree of branching of the product were discussed by determining hydroxyl value, carboxyl conversion rate, product molecular weight and weight distribution. The result showed that the anticipated hyperbranched polyester was synthesised at the condition of catalyst amount0.75%,180℃and the reaction time is2.5h. The reaction time, catalyst amount and monomer structure is the key factor on the product structure and its performance. In hyperbranched polyester, the end hydroxyl groups are easily to be modified and further dedicate outstanding performance to the polyester. The quaternary ammonium salt was introduced into the structure of hyperbranched polyester by etherification. The mentioned-above hyperbranched polyester and2,3-epoxypropyl hexadecyl dimethyl ammonium chloride reacted by oil bath at50℃for10hour, or microwave heating at70℃for1hour. The synthesized hyperbranched polyester quaternary ammonium salt (QHPE) was characterized with FTIR and NMR. The result showed that QHPE, inherited the fine nature of hyperbranched polymer and quaternary ammonium salt, could be used as the accelerator for alkaline hydrolysis of polyester fabric. Both the hyperbranched polyester quaternary ammonium salts by different heating methods significant accelerated the alkaline hydrolysis of polyester fabric. In addition, this study also discussed the influence of QHPE amount, sodium hydroxide amount, processing time and temperature on the alkaline hydrolysis of polyester fabric.