The Preparation Of Siloxane-polyester Copolymer And Study In Application

In this thesis, the methods of preparating new type polyesters and siloxane- polyester copolymers were studied. And their application were discussed thoroughly.New type polyesters were synthesized with polypropylene glycol(PPG), polyethylene glycol(PEG), duality acid and fatty acid.the optimal experiment conditions are as follows:the reaction temperature is 190℃for 6h, p-toluenesulfonic acid is the catalyst and the weight concentration is 0.3%～0.4%. The influence factors to product's capabilities such as the sort of reactants,the molecular weight and the ratio of different materials are discussed. Such are the conclusion: the sort and the ratio of duality acid and fatty acid are not important for the capabilities of products.the molecular weight and the ratio of polypropylene glycol and polyethy- lene glycol are determinant. as the molecular weight of polypropylene glycol and polyethylene glycol increasing, the defoaming capability of products is falling and as the molecular weight of polypropylene glycol reducing, the change is not distinct. The optimal ratio of polypropylene glycol and polyethylene glycol is 7:3.Low hydrogen-containing Polyhydrosiloxanes were synthesized with octame- thylcyclotetra-siloxane and high hydrogen-containing polyhydrosiloxanes as materials. Then the siloxane-polyester copolymers were synthesized with polyesters , Low hydrogen-containing Polyhydrosiloxanes by graft reaction. The influence factors such as the temperature ,the reaction time,the amounts of catalyst,the mol ratio of reactants are studied and the reasonable conditions were obtained:the temperature is 110℃,the reaction time is 10h,the amounts of catalyst is 0.35%, the mol ratio of polyesters and low hydrogen-containing Polyhydrosiloxanes is 1:1.2. The relations of the structure of polyester, the hydrogen- content of polyhydrosilox- ane et al.with the capabilities of siloxane-polyester copolymers were analyzed thoroughly and the concerned conclusion was drawn: when the hydrogen-content of polyhydrosiloxane is 0.4%,the blocking quotiety of polyesters is super.the turbidity point of siloxane-polyester copolymers is falling with the hydrogen-content of polyhydrosiloxane raising,and the defoaming capability of product is the best when the hydrogen-content of polyhydrosiloxane is 1%. the blocking quotiety is increas- ing and the turbidity point is dropping as the hydroxyl proportion in siloxane- polyester copolymers augment,the optimal mol ratio of hydroxyl content and the hydrogen-content is 5:6.the mol ratio of PPG and PEG raising,the turbidity point of siloxane- polyester copolymers is dropping,and the best ratio is 7:3 in defoaming capability.To decrease maufacture costs and improve the ratio of efficiency and outlay.The not exensive emulsifier, hydrophobe and other adminicle were mixed with self-made polyesters, siloxane-polyester copolymers to obtain defoamers which be better than imported.And the factors in the process of compound were studied particularly and systemically.the prime project is as follows:the siloxane-polyester copolymer is synthesized with PPG2000,PEG400,1% hydrogen-containing Polyhydrosiloxanes, hexane diacid,which mol ratio of materials is 7:3:6:5.emulsifying agents are SP-60 and tw-60,the value of HLB is 8.5.its dosage is 5%.the concentration of control- bubble resin is 5%. the concentration of liquid hydrocarbon A is 20%. the concentration of liquid hydrocarbon B is 10%.the dosage of hydrophobe is 15%~20%.The condensation and used environment of defoaming agent were studied ,the experiments show that self-made defoamer can be the same with many bubbly systems,such as anion, zwitterions, Nonionic bubbly liquid et al.and it can be used from acidity to alkalescence conditions.the fitting dosage (the ratio of vol) is 9‰～10‰to polyester,6‰to siloxane-polyester copolymer,and 3‰to mulriple defoamer.The conclusions in this thesis are not only consisting in synthesizing new type polymers not seen at home,but disclosing the relations of structure and performance of products in deep sense.And establishing the base of developping defoamers which adapt to special environments further.