| 摘要 |
<p>The invention relates to a composite containing a network of parallel strong fibres, having a strength of at least 6 dN/tex, a modulus of at least 130 dN/tex and an energy absorbed during fracture of at least 8 J/g in a thermoplastic polyurethane matrix, char acterised in that the matrix contains a polyurethane that is amorphous at room temperature. The invention also relates to a prepreg containing at least two layers of a network of strong fibres in a thermoplastic polyurethane matrix, the fibres and matrix being as described in the invention, and to a process for preparing the prepreg according to the invention, characterised in that strong fibres are wetted with an aqueous polyurethane dispersion and the polyurethane is amorphous at room temperature. The invention also relates to a helmet made from the composite according to the invention.</p> |
