Liquid crystal polymers

A material of general formula I ##STR23## m=at least 5;

• X.sub.1 and X.sub.2 are independently selected from formula IA:
• ##STR24## wherein Y is selected from COO, OCO, O, S, CHOH, CHF, CH.sub.2 ;
• Q=(CH.sub.2).sub.n wherein one or more non-adjacent methylenes may be replaced by O and n=1-20;
• Z is selected from O, S, single covalent bond, COO, OCO;
• when Y is CH.sub.2 then n may also be 0;
• ##STR25## represents any mesogenic group;
• X.sub.1 and X.sub.2 are also independently selected from H, OH, OCOR.sup.1, COOH, CO.sub.2 R.sup.1, (CH.sub.2).sub.p OH, (CH.sub.2).sub.p CO.sub.2 H, --(CH.sub.2).sub.p OR.sup.1 or --(CH.sub.2).sub.p CO.sub.2 R.sup.1 and p=1-20, R.sup.1 =H or C.sub.1-16 alkyl;
• when R.sup.1 =C.sub.2-16 alkyl the terminal CH.sub.3 group may be replaced by Br or Cl;
• provided that at least one of X.sub.1 and X.sub.2 is selected from formula IA.