Abstract: A copolymer containing repeat units formed from the monomers (I) and (II), wherein each R1, if present, is independently hydrogen or hydrocarbyl; r is 0, 1 or 2; s is either 2 or 3; R2–R4 are each independently hydrogen or hydrocarbyl; R5 and R6 are each independently hydrogen, halo or hydrocarbyl; Pd? is the anion formed by loss of a proton from a proton donating group Pd—H; Z is either a bond or hydrocarbyl; R7 and R8 are each independently hydrogen, halo or hydrocarbyl; and either (a) A is an electron accepting group and W is either hydrogen or hydrocarbyl, (b) W is an electron accepting group and A is either a bond or hydrocarbyl or (c) both A and W are electron accepting groups. The invention also provides a method for preparing the copolymer by polymerising a mixture of (I) and (II) or their non-ionised precursors, preferably by exposure to ultraviolet radiation.

Abstract: Compounds of formula ##STR1## are provided which may be used in a variety of devices including liquid crystal devices, piezoelectric devices, pyroelectric devices and in optical recording media, wherein X.sub.1 and X.sub.2 are independently selected from H, CN, COCH.sub.3, CO.sub.2 CH.sub.3, m=at least 5; X.sub.3 and X.sub.4 are independently selected from formula (IA), ##STR2## 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 CH2 then n may also be O; formula (A) ##STR3## represents any mesogenic group; X3 and X.sub.4 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.

Abstract: Liquid crystal polymer materials used in liquid crystal devices, piezoelectric devices, pyroelectric devices and recording media are described.