Study On The Toughening Modification Of Epoxy Resin Adhesive

In this paper, we use the polyether polyol N210, N220, polyester polyol M2and TDI asraw materials.First, through the use of prepolymerized synthesis method to make the PUprepolymer, then use the PU prepolymer modifying the epoxy resin, we use thedicyandiamide as a curing agent, PU, CTBN, PSF as toughener toughened epoxy resin andstudied PU and PSF composite toughened epoxy. Study of the modified epoxy adhesiveproperties, mechanical properties, dynamic mechanical thermal performance, curingdynamics.Through the non-isothermal DSC, We determine the curing characteristics temperaturethe apparent activation energy，the curing reaction rate constant, curing kinetics equation ofthe dicyandiamide curing modified epoxy E-51, E-44, E-20, at the same time we determinethe modified epoxy resin the curing process.Through the use of prepolymerized synthesis method to make the PU prepolymer, theresults show that the polyester polyurethane prepolymer better than polyether-type, when theamount of the prepolymer is30%, E-51has the best overall performance, the roomtemperature shear strength is36.28MPa, the room temperature peel strength is6.87KN/m;For different epoxy, adhesive strength: E-20>E-44>E-51, when the amount of prepolymer is20%,E-20: E-44=1:1, the shear strength of room temperature,100°C,150°C, and roomtemperature peel strength were as follows:43.87MPa22.32MPa,7.99MPa and10.02kN/m.DMA analysis, with the prepolymerization body dosage of increase, the glass transitiontemperature of the modified resin become lower, the temperature performance is lowered.Study the CTBN toughening epoxy E-51, results show that CTBN can significantlyincrease the toughness of the epoxy E-51, when the amount of the CTBN is30%, the overallperformance is best, the peel strength:6.93KN/m, room temperature shear strength:41.02MPa.With the increases of CTBN, the bending strength, tensile strength, impactstrength and elongation of the modified resin increased, the glass transition temperaturebecome lower.Study the PSF toughening epoxy E-51, results show that the PSF effectively improve theheat resistance of the modified resin, while increasing the toughness of the modified resin, theappropriate Add PSF can effectively improve the pull tensile properties, impact properties and flexural properties of the modified resin, but the excess add will lead to the viscosity ofthe modified system, and it is too hard to operation.Study the operating performance of PU, CTBN and PSF toughening epoxy E-51, whenuse CTBN toughening, the viscosity of the modified resin is large, it will be drawingphenomenon, not conducive to the construction, while with increasing temperature theviscosity sharp decline, and it will be flowing; excess add PSF, the modified epoxy resin withhigh hardness, cohesive strength, difficult construction; PU modified resin, may beintroduced to the portion of the cross linked structure, and with the temperature increases itsviscosity variation is small, it can’t draw, at room temperature it has a low viscosity, and easyto operate.Study PU and PSF composite toughened epoxy resin, and results show that the amountof PU=20phr, PS=15phr the toughening modification is the best, the shear strength of roomtemperature,100°C,150°C and peel strength is38.98MPa and23.74MPa,14.45MPa and10.94KN/m, while the mechanical properties have been improved; Through compositetoughened, we get the high strength, toughness and good temperature resistance componentribbon adhesives, we get the purpose of the experiment.