Research On PAPI/PPG Prepolymer Modified UPR And Its Properties

Unsaturated polyester resins in our time, has been used very broad. However, due to curing of unsaturated polyester resins, toughness is poor, so that the use has been limited. Therefore, unsaturated polyester resins for the shortcomings in this regard, many researchers have been dedicated to the toughening of unsaturated polyester resin modified. Modification of the conventional method of the past made some effect, but at the same time reducing their own high-strength characteristics. Polyurethane prepolymer with unsaturated polyester resin blend modified method can solve this problem. Blending modification can be integrated the advantages of polyurethane and unsaturated polyester resins, the blend modified by the modified unsaturated polyester resin with high strength, but also has good toughness.In this paper, we do some Researches on PAPI/PPG prepolymer Modified UPR and its properties.First,through the NCO content and IR on the PAPI/PPG prepolymer synthesis was studied to select the best reaction conditions, and in the case of the different feed ratio to test the viscosity of prepolymer, research and pre-feed ratio Polymer viscosity relationship; The experiments showed that higher feed ratio, synthesized low viscosity prepolymer; at 80℃,3 hours of synthesis conditions, PAPI and PPG can reaction completely.In the research on pre-polymer blend with the UPR, we studied the PU blends added content, feed ratio, PPG molecular weight on the properties of blending resin. After a test showed that:When the PAPI:PPG=3,the prepolymer synthesis of the best modifier. PU blends with the added amount of the increase in bending strength and tensile strength first increased and then decreased,17% in the PU content, they both reached the maximum; impact toughness first increases and then decreases, in the PU content 6% of the time, to achieve maximum impact toughness; elongation first increase and then decrease, in the PU content is 13% of the time, breaking the maximum. HDT Blend resin temperature rise. As the PU content increased, the resin blend HDT temperature rise, joining the PU content to reach around 6%, HDT began to slow the temperature rise in temperature, HDT temperature close to 85℃, higher than the unmodified UPR is about 15℃, heat enhancement effect is obvious. PPG molecular weight of 300 and 400, modified UPR less the same viscosity, the viscosity of the former is smaller; PPG molecular weight of 400, modified UPR can reach the maximum tensile strength of 62.9MPa, the unmodified was increased by 83%, then the elongation at break was 5.9%, maximum bending strength is 104MPa, PPG molecular weight of 600, maximum toughness, reach to 30.2 kJ/m2; after adding prepolymer, the impact of cross-section showing ductile fracture.In the blending resin composite materials, modified unsaturated polyester resins, unsaturated polyester not modified vinyl resin has been common among the three in his capacity as the matrix tensile comparison of performance and bending properties. Then, to examine the modified unsaturated polyester resin composite overall performance, we make it with different matrix composite material on the experimental water together and fatigue experiments, the last of the unsaturated polyester resin modified pull The cross section morphology of extended analysis. The results showed that:Just the bending strength of the unmodified is 331MPa, blending resin modified flexural strength reached 561MPa, increased 69.5%, compared to the 3201 vinyl resins, bending strength increased by 50%; change After the tensile properties of have been improved, blending resin tensile strength of the unmodified polyester resin increased by 16.2%, the tensile modulus increased by 15.2%, the elongation rate increased 15.7%; and 3201 vinyl resin composite material compared to the tensile strength of the resin blend increased 17.2%, and tensile modulus increased by 6.2%, the elongation rate increased by 22%; modified unsaturated polyester ester composite water performance:the condition of 80℃, after 7 cycles of immersion experiments, the bending strength of the retention rate was 74%, exceeding the UP resin matrix composite materials,36%, better-than-modified amine curing Epoxy composites of 65%; modified unsaturated polyester composites is also very excellent fatigue resistance:After 40 million in the bending vibration fatigue, its flexural modulus also 63% Only epoxy matrix composites than 5 percentage points lower; modified unsaturated polyester resin and glass fibers have a good interface performance.