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 consisting of:
(A) 20-99.5 wt % of 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;
(A2) optionally one or more dyes F; and
(A3) optionally one or more assistants H; and
(B) 0.5-80 wt % of 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,
(C) 0-79.5 wt % of polymer D, and
(D) optionally one or more adhesion promoters,
wherein optionally the light transmission through said fiber composite material W is not less than 10% higher than with a comparable fiber composite material that is the same as the fiber composite material W except that monomers A-II fully replace said monomers A-I, and
wherein the flexural strength of said fiber composite material W is not less than 20% higher than with a comparable fiber composite material that is the same as the 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 copolymer C has a construction comprising not less than 0.1 wt of monomers A-I.
3. The fiber composite material W as claimed in claim 1 wherein said thermoplastic polymer composition A comprises 90-99.5 wt % of said copolymer C.
4. The fiber composite material W as claimed in claim 1 wherein said 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).
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 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 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, styrene (S) as monomers A-II; and
(B) said 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 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 is the same as the 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 50% higher than with a comparable fiber composite material that is the same as the 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.
12. A fiber composite material W obtained by a method comprising the steps of:
(i) providing:
(A) 20-99.5 wt % of 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;
(A2) optionally one or more dyes F; and
(A3) optionally one or more assistants H; and
(B) 0.5-80 wt % of fibers B whose surface displays functional groups B-I which are capable of forming a covalent bond with said monomers A-I, but not with said monomers A-II;
(C) 0-79.5 wt % of polymer D, and
(D) optionally one or more adhesion promoters,
(ii) melting said thermoplastic polymer composition A and contacting same with said fibers B from step (i); and
(iii) reacting at least some of said monomers A-I of said copolymer C and at least some of said functional groups B-I of said fibers B from step (ii) to form covalent bonds,
wherein optionally the light transmission through said obtained fiber composite material W is not less than 10% higher than with a comparable fiber composite material that is the same as the fiber composite material W except that monomers A-II fully replace said monomers A-I, and
wherein the flexural strength of said fiber composite material W is not less than 20% higher than with a comparable fiber composite material that is the same as the fiber composite material W except that monomers A-II fully replace said monomers A-I.
13. The fiber composite material W as claimed in claim 1 wherein said fibers B are embed layerwise as wovens into said fiber composite material W and wherein no adhesion promoter from the group consisting of aminosilanes and epoxy compounds was used in the production of said fiber composite material W.