Toughening of epoxy resins using nano rubber particles: Effects of particle size, surface functionality, and morphology on impact fracture propertiesAuthor(s): Ahmed I.Hashim, Maher A.El-Sockary, Usama F.Kandil*, Nevien O.Shaker, Mona A.Abd El-Rahman
A novel method to synthesis reactive nano-rubber particles is described. Considered as a frontier engineeringmaterial, reactive nano-rubber particles will find the way in almost all applications, specifically, in toughening of brittlematerials. The process involves two steps: natural rubber sample (cis- 1,4-polyisoprene) is emulsified using soap-in-situmethod to sub-micro (nano) size particles, followed by a crosslinking reaction in the bulk of the particle. Some remaining double bonds on the surface were then used for further functionalization (epoxidation). Then, these epoxidized nano-rubber particles have been introduced before curing reaction to epoxy resins which is considered as a novel method for providing toughness with excellent adhesion in brittle epoxies. The combination of Scanning Electron Microscope (SEM) and Transmitting Electron Microscope (TEM) results indicates the effectiveness of the grafting reaction and consequently the interfacial adhesion between the dispersed rubber particles and the continuous domain of the investigated epoxy resins. Incorporation of 15 w% of nano-rubber particles enhances the flexibility of the modified epoxy sample to the required value.