Synthesis Of Hyperbranched Polyester And Its Application In Polymer Emulsion

Hyperbranched polyester was synthesised by direct melting method, Trimethanolpropane(TMP) as a core monomer and2,2-Dimethylol propionic acid (DMPA) as AB2monomer during the synthesis.The inflluence of dosage of catalyst,reaction tempeartureon the synthesis of hyperbranched polyester was studied.The optimal synthetic processwas obtained through experiments.The result of synthesis of HBPE showed the optimalreaction were that p-toluenesulfonic acid as catalyst and its amount used was0.8%,reaction tempearture was140℃,and the two kinds of monomer reacted according to acertain proportion..The second generation to the fifth generation hyperbranchedpolyester were synthesised follow the craft.The intrinsic viscosity of HBPE wasmeasured,it has a lower viscosity at room temperature,intrinsic viscosity of the secondgeneration to the fifth generation hyperbranched polyester ranged from3.28ml/g to5.95ml/g.Viscosity average molecular weigh of HBPE was measured accordingto,intrinsic viscosity,and it ranged from1591g/mol to3519g/mol.Hydroxyl value ofthe second generation to the fifth generation hyperbranched polyeste weremeasured,their value ranged from542.3mg/g to452.1mg/g,it can be proved there are alot of hydroxyl radical in hyperbranched polyester.Acrylic-terminated hyperbranched polyester(AHBP) was synthesised by chemicalreaction between HBPE and maleic anhydride,acrylic groups were grafted on thehydroxy of HBPE.The product was characterized by IR,atlas showed that hydroxyl wasreduced and acrylic group was appeared.Acid value of AHBP was measured andreaction degree was characterized by it,with the increase of AHBP’generation,acidvalue ranged from183.0mg/g to412.5mg/g,and conversion ranged from70.4%to87.4%.Content of double bond of from the second generation to the fifth generationAHBP were measured by iodometry,content of double bond was increased along withthe increase of generation,content of double bond ranged from0.318mol/100g to0.72mol/100g.The second generation AHBP modified emulsion as an example,polymerizationtemperature,ratio of emulsifier,dosage of initiator were studied.Optimal synthetic process was obtained that polymerization temperature is65℃, SDS/OP-10is3, dosageof initiator is0.4%of all monomers,and the amount of AHBP is1%~5%of allmonomers is relatively appropriate.Study of AHBP modified styrene-acrylic emulsion such as conversion rate,gelcondensation rate,solid content,calcium ion stability,viscosity,adhesion,water absorptionand hardness.Conversion rate and solid content are decreased,gel rate and condedsationrate are increased along with the increase of AHBP’generation and its dosage.Calciumion stability of AHBP modified emulsion has improved and high generational AHBPmodified emulsion has a better stability.The viscosity of AHBP modified emulsion wasincreased along with increase of dosage of.Water absorption of modified emulsion canbe reduced by10%,hardenss of latex film promoted a grade.Crosslinking degree ofmodified emulsion was measured,data showed that modified emulsion has a certaincrosslinking degree.AHBP has a property like crosslinking agent,it can make theemulsion crosslinking.Zinc acetate as a crosslinking agent was introduced in modified emulsion andmeasured its crosslinking degree and property,found that the crosslinking degreeincreased37.8%at most.The emulsion has some bad properties after crosslinking agentadded in,such as stability of calcium,viscosity,and adhesion of latex film,but at the sametime the impact resistance,water resistence and hardness were promoted.