Role of silane coupling agent and polymeric film former for tailoring glass fiber sizings from tensile strength measurements

Tensile strengths of differently sized E-glass fibres have been characteris ed using a bimodal Weibull two parameters cumulative distribution function. By comparing unsized fibres, pure silanes, different film formers, and sil ane/film former combinations, a comprehensive summary on the healing effect for surface flaws in relation to the type of sizing emulsion has been obta ined. The great influence of the film former, which is the main component o f the sizing by weight, was shown to affect both the healing of initially o ccuring flaws in the unsized fibre and the possibility of creating new defe cts. Besides the single influence of the film former, the synergetic effect of silane and film former polymer has been shown. In fact, the presence of sizing influences both the population of flaws on the fibre surface and th e structure of the interphase, which will be created from the impregnation with a polymer matrix. Data from statistics of fracture as a function of th e nature of sizings were discussed according to the literature on stress co rrosion of E-glass filaments. (C) 2001 Kluwer Academic Publishers.