Translucent fibre composite materials comprising chemically modified polymers
The present invention relates to a fibre composite material W of increased translucency and/or mechanical strength, comprising a copolymer C encompassing monomers A-1, where A-1 form covalent bonds with functional groups B-1 on the surface of fibres B embedded in the fibre composite material W, and this fibre composite material W has greater translucency and/or mechanical strength than a fibre composite material Win which the copolymer C contains no A-1. The present invention further embraces a method for producing a fibre composite material W of increased translucency and/or mechanical strength.
1. A fiber composite material W comprising:
(A) a polymer matrix in the form of a thermoplastic polymer composition A comprising:
(A1) at least one copolymer C comprising monomers A-I and monomers A-II and optionally further monomers, wherein monomers A-I are selected from the group consisting of maleic anhydride (MA), N-phenylmaleimide (PM), tert-butyl (meth)acrylate, and glycidyl (meth)acrylate (GM);
(A2) optionally one or more dyes F; and
(A3) optionally one or more assistants H; and
(B) glass fibers B whose surface displays functional groups B-I which form a covalent bond with said monomers A-I, but not with said monomers A-II,
wherein the light transmission through said fiber composite material W is not less than 10% higher than with a comparable fiber composite material that has the same structural properties as fiber composite material W except that monomers A-II fully replace said monomers A-I, and
wherein optionally the flexural strength of said fiber composite material W is not less than 20% higher than with a comparable fiber composite material that has the same structural properties as fiber composite material W except that monomers A-II fully replace said monomers A-I.
2. The fiber composite material W as claimed in claim 1 wherein said fiber composite material W consists of:
20-99.5 wt % of the thermoplastic polymer composition A;
0.5-80 wt % of the glass fibers B; and also
0-79.5 wt % of polymer D.
3. The fiber composite material W as claimed in claim 1 wherein said copolymer C comprises not less than 0.1 wt % of monomers A-I.
4. The fiber composite material W as claimed in claim wherein said thermoplastic polymer composition A comprises not less than 90 wt % of said copolymer C.
5. The fiber composite material W as claimed in claim 1 wherein said copolymer C is a styrene copolymer C comprising styrene (S) as monomers A-II.
6. The fiber composite material W as claimed in claim 1 wherein said functional groups B-I at the surface of said glass fibers B are selected from the group consisting of hydroxyl groups, ester groups, and amino groups.
7. The fiber composite material W as claimed in claim 1 wherein said glass fibers B embed into said fiber composite material W layerwise.
8. The fiber composite material W as claimed in claim 1 wherein:
(A) said polymer matrix A comprises not less than 75 wt % of styrene copolymer C, maleic anhydride (MA) as monomers A-I, and styrene (S) as monomers A-II; and
(B) said glass fibers B are glass fibers displaying hydroxyl groups in the form of silanol groups as functional groups B-I on the surface,
wherein the MA moieties are at least partly esterified with the silanol groups on the surface of said glass fibers B.
9. The fiber composite material W as claimed in claim 1 wherein the light transmission through said fiber composite material W is not less than 15% higher than with a comparable fiber composite material that has the same structural properties as fiber composite material W except that monomers A-II fully replace said monomers A-I.
10. The fiber composite material W as claimed in claim 1 wherein the flexural strength of said fiber composite material W is not less than 20% higher than with a comparable fiber composite material that has the same structural properties as fiber composite material W except that monomers A-II fully replace said monomers A-I.
11. The fiber composite material W as claimed in claim 1 wherein no adhesion promoter from the group consisting of aminosilanes and epoxy compounds was used in the production of said fiber composite material W.