Effect of Irradiation on the Strength Properties of Polyethylene-Matrix Glass-Reinforced Plastics

Abstract

The influence of radiolysis on the strength of glass fiber-reinforced composites was studied. It was found that irradiation of a single-ply microplastics (MPs) reinforced preliminarily by application of polymeric finishes and sizings led to a drop in strength, which was inversely proportional to the dose, at the initial irradiation stage. This effect, which was accompanied by a fall in the magnitude of the elastic modulus, was assumed to be due to the initial failure of the stressed adhesive interlayer between microfibers of a strand, which leads to a decline in the ability of the stress to be transferred to the monofilaments upon loading of microplastics. It was shown that as the radiation dose in air increased, the breaking strength of MPs passed through a maximum at 1000 kGy, whereas that of the PE matrix alone noticeably decreased. These results suggest the formation of chemical bonds between the polymer matrix and the surface of the glass fiber. It was found that the strength of MPs sharply increased upon irradiation in vacuum at doses as low as 10-50 kGy.

The Effect of Gamma-Radiation on the Physicomechanical Properties of Glass-Fibre-Reinforced Plastics Based on Thermoplastic Matrices

“…It is connected with the influence on the process of radiolysis of residual internal stresses (RISs), primarily of the thermal type, caused by the difference in the coefficients of thermal expansion of the polymer matrix and the reinforcing GFs in the GFRMP [9,10]. Here it is evident that low doses of gamma radiation should break down primarily the stressed microregions of the polymer matrix in the GFRMP, directly adjacent to the surface of the GFs [5,8,11]. With further increase in the radiation dose, with this process there begins to compete the process of structure formation of the polymer matrix, i.e.…”

“…Earlier [4,5] it was shown that, during the treatment of single-layer glass-fibre-reinforced microplastics (GFRMPs) based on a PE matrix with small doses of gammaradiation, strengthening of both the glass composite and of the matrix itself is observed. Here it was supposed that the strengthening of the GFRMP is due to the formation during irradiation of chemical bonds not only between the different macromolecules of the matrix (radiation structure formation of the matrix) but also between the matrix and the surface of the reinforcing glass fibres (GFs).…”