Abstract: The use of a multi-functional, chromophore containing, polymerizable compound for producing an optical element having non-linear optical properties (an NLO element) wherein the multi-functional chromophore is a compound capable of being polymerized into a cross-linked network and of being poled under the influence of an electric field whilst being polymerized into the cross-linked network, the compound having the generalized formula(D) (C) (A) (F)D, C, A and F representing covalently linked moieties where C represents at least one conjugated system of .pi.-bonds,A and D represent at least one respectively .pi.-electron acceptor and .pi.-electron donor groups linked at opposite ends of the conjugated system, and are preferably conjugated with the conjugated system of .pi.-bonds (C) and where more than one moiety A, C or D is present they may be the same or different,F represents at least two polymerizable functional groups, which may be the same or different, attached to the .pi.

Abstract: Amphiphilic compounds and oligomers and polymers derived therefrom suitable for Langmuir Blodgett deposition wherein the compounds have a polyamide backbone and hydrophobic groups pendant therefrom which pendant groups preferably contain chromophore groups. The compounds can be used to form non-centrosymmetric bilayers and are useful for forming various non-linear optical elements.

Abstract: A thermoplastic polymer composition comprising a thermotropic polymer and 0.025 to 5% by weight of the composition of a finely dispersed particulate inorganic additive wherein the additive is a material having at least 95% by weight of particles with at least one dimension less than 1 micron and preferably less than 0.1 micron and is an organophilic or organophobic material which has a settling volume of at least 10 when measured in a liquid in which the particulate material is compatible. The presence of the inorganic additive in the thermotropic polymer gives rise to an improved processing behavior.

Abstract: Optical fibre cables are produced containing an extruded support member of thermotropic liquid crystalline polymer in which the extrusion conditions are used to control the thermal expansion coefficient of the support member. The support member may be extruded on to the support member. In this case extrusion conditions may be used to induce a compressive strain on the fibre which can counteract the thermal change in length of the fibre when subject to temperature variations so that a cable having an optical path length which is less sensitive to temperature variation can be produced. Support members which provide a loose fitting sleeve over the fibre can be produced by control of extrusion conditions to have a thermal expansion coefficient of not less than -5.times.10.sup.-6 /.degree.K.

Abstract: A process of polymerizing a polymerizable material in an inert organic liquid medium, in which the polymer formed from the monomer or monomers is insoluble, comprising dispersing the polymerizable material in the organic liquid in the presence of a finely, divided particulate material comprising an inorganic portion insoluble in the organic liquid medium and in combination therewith, preferably by covalent or ionic bonding, hydrocarbon chains containing at least 8 carbon atoms, the hydrocarbon chains being soluble in the organic liquid medium and heating the mixture to polymerize the polymerizable material to a required degree of polymerization. The process provides a means of stabilizing dispersion polymerizations which need to be carried out at very high temperatures to effect the polymerization.

Abstract: Melt processable, aromatic copolyesters containing 15 to 40 mole % of 4-oxybenzoyl moieties from 0.25 to less than 2.5 mole % of randomizing moieties, which are preferably 2-6 oxy naphthoyl moieties, the balance of moieties being equimolar proportions of moieties derived from hydroquinone and isophthalic acid. The preferred polymers are made by a dispersion polymerization process using as a dispersion aid a finely divided particulate material having at least 95% by weight of particles with at least one dimension less than 1 micron.

Abstract: Optical fibre cables are produced containing an extruded support member of thermotropic liquid crystalline polymer in which the extrusion conditions are used to control the thermal expansion coefficient of the support member. The support member may be extruded on to the support member. In this case extrusion conditions may be used to induce a compressive strain on the fibre which can counteract the thermal change in length of the fibre when subject to temperature variations so that a cable having temperature variation can be produced. Support members which provide a loose fitting sleeve over the fibre can be produced by control of extrusion conditions to have a thermal expansion coefficient of not less than -5.times.10.sup.-6 /.degree.K.

Abstract: The invention provides a method of influencing the orientation of the polymer molecules in a melt of molecularly orientable polymer by subjecting a composition containing the polymer and a megnetically susceptible filler to a magnetic field of at least 0.005 Tesla prior to or during the formation of a shaped article from the melt. Compositions for use in the invention comprise a thermoplastic polymer and at least 0.05% by weight of a magnetically susceptible filler, particularly a ferrite. The invention is most easily applied to thermotropic polymer compositions.