Epoxy based matrices for structural composites prepared by ionizing radiation. Morphological and thermal behaviour

Radiation curing of epoxy resins in the presence of engineering thermoplastic: a way to produce nanostructured matrices for aerospace composites

Radiation processing for synthesis of structural materials

Processi di cura di resine epossidiche mediante radiazioni ionizzanti per la realizzazione si materiali compositi per il settore aerospaziale. Influenza delle condizioni operative sulle proprietà finali

E-beam curing of epoxy based blends in order to produce high performance composites

In this work, blends of a difunctional epoxy monomer and a thermoplastic toughening agent are E-beam irradiated at two different dose rates and two different total absorbed doses. The influence of the processing conditions on the thermal properties and on the morphology of the obtained matrices has been investigated. In particular, it is shown how the increase of the dose rate causes an increase of the temperature during irradiation, thus inducing a simultaneous thermal and radiation curing. On the contrary, at low-dose rate the system mainly undergoes to radiation curing, thus making the cured material very sensible to a post-irradiation thermal treatment with a significant improvement of …

Properties-morpholohy-processing relationships in the e-beam curing of epoxy resin-thermoplastic blends for advanced composite matrices

Electron beam induced polymerisation of MMA in the presence of rubber: a novel process to produce tough materials

Abstract PMMA-rubber blends are formed through electron beam induced in situ polymerisation. The influence of rubber nature and irradiation dose has been investigated through mechanical tensile tests, solubility analysis and the results were related to material structure investigated through atomic force microscopy. Some blend formulations present a significant increase of ductility with respect to pure PMMA, without a dramatic decrease of modulus, yield stress and stress at break values. The results are interpreted on the basis of the criterion of the critical inter-particle thickness.

Ionizing radiation induced curing of epoxy resin for advanced composites matrices

Abstract The radiation curing of an epoxy monomer in the presence of an iodonium salt, as photo initiator, is studied. Systems with different concentrations of photo initiators have been polymerized via both gamma rays and e-beam, at various dose rates. The aim of this work is to investigate how the photo initiator concentration and the irradiation dose rate affect the temperature of the systems during curing and how the different thermal histories influence the dynamic mechanical thermal properties of the obtained materials.

Pulse radiolysis and theoretical investigation on the initial mechanism of E-Beam polymerization of epoxy resins. The results obtained on (phenoxymethyl)oxirane

Pulse radiolysis and theoretical investigation on the initial mechanism of the e-beam polymerization of epoxy resins. The results obtained on (phenoxymethyl)oxirane

Abstract The radical cation of (phenoxymethyl)oxirane ( PGE ⋅ + ) is generated by pulse radiolysis in dichloromethane solution and by direct action of radiation on the title compound. In the pure system its UV–vis spectrum is characterized by two bands at 340 and 430 nm, such that the electronic structure corresponds to a dipole bearing the positive charge on the phenoxy side. At the same time, the phenoxy-oxirane bridge is weakened. Then, the radical cation fragments into a phenoxonium ion and an oxyranylmethyl radical ( k PGE - fragm = 1.16 × 10 7 s - 1 ) . The latter immediately rearranges to an allyloxyl radical by ring opening. It is then conceived that the action of onium salts, as ra…