Synthesis And Application Of UPR With Low Viscosity And Low Shrinkage Used In Putty

The unsaturated polyester resin was widely used in Fiber Reinforced Plastics(FRP)composite products,such as construction,corrosion protection,insulation,etc..Because it had the characteristics of the simple production process,readily available raw materials and excellent properties of mechanics,chemical resistance and electricity.It could be cured under the room temperature and normal pressure with a good process performance.With the wide application of unsaturated polyester resin in construction,coating,aerospace and other fields,the higher requirements were put forward for the properties of unsaturated polyester resin.But one of the drawback of the unsaturated polyester resin was the big shrinkage during curing,therefore,the quality of the products was easily affected.So it was hoped that the unsaturated polyester resin of putty was synthesized with smaller shrinkage and more excellent comprehensive properties in curing.In this paper,hyperbranched unsaturated polyester resin and xylene formaldehyde unsaturated polyester resin were synthesized.They were in view of the situation that unsaturated polyester resin had bigger shrinkage during curing,the products easily produced cracks and the quality of the products was affected,and increasing the amount of filler could save production cost by reducing the viscosity of the resin.Hyperbranched unsaturated polyester resin was applied in putty to solve the issues on the larger shrinkage rate of domestic putty due to its features of less winding between molecular chains,low viscosity and small shrinkage after curing,etc..At present,due to the complicated technology and serious pollution resulting from the application of expensive solution with low boiling point during the synthesis of the hyperbranched unsaturated polyester resin and the application of distillation during the solution recycle and that the diluted active monomer during the production of hyperbranched unsaturated polyester resin was not the cheap and large amount of styrene,it was not good enough to apply the traditional redox curing system.To solve the above problems,in this paper,the dibutyl phthalate was brought in to replace the traditional solution with low boiling point in the reduction of viscosity during the synthesis of resin,which was good for the reaction,saved the recovery link of the solution,simplified the technology,improved the intersolubility of products and styrene and the curing performance of products in an economic and eco-friendly way.Because the dosage of DBP,acrylic feeding mode and reaction temperature had significant impact on the synthesis and properties of the resin,the influence of dosage of DBP,acrylic feeding mode and reaction temperature on the synthesis process and performance of the resin were studied in the synthesis of hyperbranched unsaturated polyester resin.The dosage of DBP is about 18.8% of the quality of raw material,the acrylic acid and phthalic anhydride was feeded,the pre-reaction temperature is about 130?,the latter part of the reaction temperature is about 140?,the integrated performance of resin was synthesized.Since the application of the unsaturated polyester in the putty has not been reported,therefore it is applied in putty.Because the performance of the resin can be fed back by the performance of the putty,the influence of the unsaturated acid and saturated acid mole ratio,the acrylic acid and styrene mass ratio(the total mass of acrylic acid and styrene were fixed)on properties of the putty were studied.When unsaturated acid and saturated acid molar ratio is about 1.3:1,ahe acrylic acid and styrene mass ratio is about 1: 4,the lowest viscosity of the resin is 0.25 Pa.s,compared with the ordinary resin,its viscosity is reduced by about 80 percent,the smallest shrinkage of the putty is 0.35%,compared with the traditional putty,the shrinkage rate decreased by about 85%.Compared with common unsaturated polyester resin,the xylene formaldehyde unsaturated polyester resin had the features of a large number of benzene rings in its molecular structure,strengthened rigidity and difficult deformation during curing,which could reduce the shrinkage rate of the putty when was applied in the putty.In addition,the increase of benzene ring could improve the solubility of styrene resin and reactive diluent,which could reduce the viscosity of the resin.Because xylene formaldehyde unsaturated polyester resin had the characteristics of low viscosity,excellent permeability,easy construction and small shrinkage during curing.At present,it had been widely used in cement,mortar,glass steel and modified resin,but its application research in putty had not been reported.So,the putty was made with the resin.When the feed ratio is about 1.15:1:0.4,the reaction temperature is about 170-180?,the dosage of hydroquinone is about 0.03% of the total mass of raw materialthe,the integrated performance of the xylene formaldehyde unsaturated polyester resin was synthesized.First of all,in the synthesis of xylene formaldehyde unsaturated polyester resin,the synthesis process conditions was explored;the different process conditions had a significant impact on properties of the resin.The influence of the feed ratio,reaction temperature and the hydroquinone dosage on the synthesis process and properties of the resin were discussed.Secondly,the synthesized hyperbranched unsaturated polyester resin was used in putty;the influence of the dosage of maleic anhydride on properties of the putty was studied.With the dihydric alcohol as modifier,propylene glycol was introduced to improve the surface dried property of putty and the diethylene glycol was introduced to improve the flexibility and impact resistance of putty.The influence of the amount of propylene glycol,the molar ratio of diethylene glycol and propylene glycol(the mass sum of diethylene glycol and propylene glycol was fixed)on the performance of putty was explored,when the dosage of maleic anhydride is about 30% of the quality of the xylene formaldehyde resin,diethylene glycol and propylene glycol molar ratio is 2:1,the lowest viscosity of the resin is 0.65 s,the smallest shrinkage of the putty is 0.32%.