In fact, epoxy resin is the product of polycondensation reaction between compounds containing epoxy groups and polyhydroxy compounds (bisphenol A, polyol, polyacid, etc.), which generally means that the molecule contains two or more epoxy groups Polymer compound. How much do you know about its toughening methods? Next, the epoxy resin manufacturers will introduce you below, hoping to help everyone.
In fact, the resin has high strength and excellent bonding performance, and has a wide range of applications in coatings, reinforcement materials, adhesives, etc., but its cured material is brittle, and its impact resistance and heat resistance are poor, making it The application is subject to certain restrictions. To this end, scholars at home and abroad have done a lot of modification research on epoxy resin to improve its toughness. The following is a detailed introduction to the toughening method of the resin:
Rubber toughening is one of the earliest studied methods of epoxy resin toughening. The toughening mechanism is currently considered to be the "silver-nail anchor" mechanism. The toughening effect is related to the connection strength between rubber and epoxy, the dispersion and compatibility of the two, and the curing process.
Since ordinary rubber itself has low strength and modulus and poor heat resistance, toughening epoxy resin will reduce its strength, modulus and heat resistance at the same time. The most popular researches at present are epoxy resins toughened by liquid rubber and core-shell rubber particles. Different types of rubber-modified epoxy resins are used. Among them, epoxy resins toughened by liquid polysulfide rubber perform well, and their impact resistance and bending resistance are improved by 400-476 percent and 55-85 percent, respectively.
Through comparison and analysis of the mechanical properties of 3 different liquid rubber toughened epoxy resin composite materials, epoxy resin manufacturers found that with the increase of rubber content, the tensile strength of the composite material continued to decrease, but the impact strength showed an increase after The decreasing trend; the higher the content of acrylonitrile in liquid rubber, the better the toughening effect on epoxy resin. Moreover, rubbers with different acrylonitrile contents have significantly different toughening mechanisms.
Using core-shell rubber particles CSR-1 as a toughening agent for epoxy resin, and 4,4'-diaminodiphenyl sulfone (DDS) as a curing agent for epoxy resin, a high-temperature curing epoxy resin was prepared.
The experimental results show that when the amount of CSR-1 is only 5phr, the matrix resin obtains a good toughening effect, and the impact strength reaches 29.1kJ/m2, which is nearly 58% higher than before toughening; the fracture toughness GIC reaches 306kJ/m2, which is 93.7% higher than before toughening; DMA and TG analysis results show that the heat resistance and modulus of the core-shell rubber particles CSR-1 toughened matrix resin have not decreased significantly, and the glass transition temperature has reached 190.4°C.
The above is the content of the resin toughening method introduced by epoxy resin manufacturers for everyone. Is everyone clear? I believe that everyone will understand the content further after reading the content. I hope that the content can be helpful to everyone. For more details, you can pay more attention to the website dynamics.