Abstract: Blends of biodegradable polymers of hydroxybutyric acid and polyolefines of improved properties are produced by incorporating a compatibilising agent which comprises a block copolymer in which at least half of the mass of one block is represented by alkyl side chains and at least half of the mass of another block is represented by side chains which comprise hydroxy acid residues.

Abstract: A process for addition polymerization of vinylic (in particular methacrylic) monomers at a temperature in the range of -20.degree. to 60.degree. c., in the presence of a catalyst comprising:(a) a first component of empirical formula (I):MT (I)whereinM is an alkali metal atom; andT is bulky hydrocarbyl which contains at least 4 carbon atoms and is optionally substituted by one or more pendent substituents, or hetero-substituted hydrocarbyl, each of which is inert in the process conditions; and(b) a (co-catalyst) second component comprising a compound of empirical formula (II):Q(X.sub.m) (Y.sub.n) Zp (II)whereinQ is Al, B or Zn;m, n and p are each 0 or an integer such that (m+n+p)=2 or 3 (depending on the appropriate valency of Q; andX, Y and Z are each independently optionally substituted bulky hydrocarbyl, orX and Y together are optionally substituted hydrocarbadiyl, and Z is optionally substituted bulky hydrocarbyl,all of which groups are inert in the process conditions.

Abstract: A catalyst for addition polymerization comprising(a) an (initiator) first component comprising a plurality of atoms M as hereinafter defined, each in a moiety of formula (I):MX(Y.sub.n)Z.sub.p (I)whereinM is Si, Ge or Snn is 0 or an integer, and p is an integer such that (n+p)=3;X is a diradical ##STR1## bound via Q to M whereQ is N, P, As or P(=T)G.D where T is O or S and G and D are each independently a bond, O or S,R.sup.1 is optionally substituted hydrocarbyl, or, when Q is P, M(Y.sub.n)Z.sub.p as herein defined,R.sup.2 is optionally substituted hydrocarbadiyl, orR.sup.1 and R.sup.2 together are hydrocarbatriyl,all such R.sup.1 and R.sup.2 being inert in the conditions of the process of the present invention; andR.sup.2 being linked directly or indirectly to any group as defined for X, or an organic radical comprising further moieties of formula (I), or one or more M(Y.sub.

Abstract: A catalyst for addition polymerization comprising:(a) an (initiator) first component of Formula (I):MX(Y.sub.n)Z.sub.p (I)whereinM is Si, Ge or Sn;n is O or an integer, and p is an integer such that (n+p)=3;X is a radical ##STR1## where Q and Q.sup.1 are each independently N, P or As;Q.sup.2 is O, S, NR or PR where R is C.sub.1-4 alkyl;R.sup.1 is H or optionally substituted hydrocarbyl; andR.sup.2 and R.sup.3 are each independently optionally substituted hydrocarbyl, or R.sup.2 and R.sup.3 together are optionally substituted aliphatic hydrocarbadiyl;all such R.sup.1, R.sup.2 and R.sup.3 being inert in the process conditions of the present invention;Y is A or OA where A is optionally substituted hydrocarbyl inert in the process conditions of the present invention, or trialkylsilylalkyl; andZ is independently any group as definedd for Y, or an organic polymer radical comprising further MXY.sub.n moieties; orp is 2 andZ.sub.2 is a group Z.sup.1 .sub.2 of the formula --OSiR.sup.5 R.sup.8 O-- where R.sup.5, R.sup.

Abstract: A catalyst for addition polymerisation comprising(a) an (initiator) first component of formula (I):M(X.sub.m)(Y.sub.n)Zp (I)whereinM is Si, Ge or Snm and p are each an integer and n is 0 or an integer such that (m+n+p)=4;X is QR.sup.1 R2.sup.2 where Q is N, P, As or P(=T)G.D where T is O or S and G and D are each independently a bond, O or S and R.sup.1 and R.sup.2 are each independently optionally substituted hydrocarbyl or together are optionally substituted hydrocarbadiyl which are inert in the process conditions of the present invention, or, when Q is P(=T)G.D as hereinbefore defined, R.sup.1 and R.sup.2 are each independently M(Y.sub.n)Z.sub.p as hereinbefore defined.Y is independently any group as defined for X, or any group selected from a group OA where A is optionally substituted hydrocarbyl inert in the process conditions of the present invention, or trialkylsilylalkyl;Z is independently any group as defined for Y, or an organic polymer radical comprising further M(Y.sub.n)Z.sub.

Abstract: A process for the preparation of polymeric compositions which comprise novel polymers and copolymers of certain 1,2-disubstituted-cyclohexadienes, aromatization of such polymers in the form of inter alia fibers, and novel aromatic polymers.

Abstract: A process for the preparation of a polyphenylene layer which comprises the steps of treating a copolycyclohexa-3,4-diene under first conditions to aromatize a portion of the aromatic rings and then under second conditions to aromatize the residual cyclohexadiene rings from the first treatment.

Abstract: A method for the preparation of 1-chloro-1,2,2,2-tetrafluoroethane which comprises treating 1,1-dichloro-1,2,2,2-tetrafluoroethane, optionally in the form of an isomer mixture, with an alkali metal amalgam in an active hydrogen containing liquid medium which includes a solvent for the dichlorotetrafluoroethane.

Abstract: An electrically conducting composition is described which comprises a polyarylene, e.g. polyphenylene, and a suitable doping agent, e.g. ferric chloride. The polyarylene is prepared from a poly(1,2-disubstitutedcyclohexa-3,5-diene).

Abstract: Vermiculite ore is contacted with an aqueous solution with at least one salt of sodium, lithium or an organosubstituted ammonium cation followed by aqueous washing so that the ore swells. The swollen vermiculite in aqueous suspension is subjected to a shearing action until a suspension containing vermiculite particles having dimensions less than 50 microns is produced with elimination from the suspension of all particles having a diameter larger than 50 microns. Water can then be removed from the suspension.

Abstract: An electrically conducting composition is described which comprises a polyarylene, e.g. polyphenylene, and a suitable doping agent, e.g. ferric chloride. The polyarylene is prepared from a poly(1,2-disubstitutedcyclohexa-3,5-diene).

Abstract: A process for the preparation of polymeric compositions which comprise novel polymers and copolymers of certain 1,2-disubstituted-cyclohexadienes, aromatization of such polymers in the form of inter alia fibres, and novel aromatic polymers.

Abstract: A process for the preparation of polymeric compositions which comprise novel polymers and copolymers of certain 1,2-disubstituted-cyclohexadienes, aromatization of such polymers in the form of inter alia fibres, and novel aromatic polymers.

Abstract: A process for the preparation of polymeric compositions which comprise novel polymers and copolymers of certain 1,2-disubstituted-cyclohexadienes, aromatization of such polymers in the form of inter alia fibers, and novel aromatic polymers.

Abstract: A composition comprising vermiculite lamellae (delaminated vermiculite) and one or more solid particulate materials which have a basic reaction in water, especially magnesium oxide. These particulate additives improve the physical properties of vermiculite articles especially the compressive strength and stability to water of foam.

Abstract: A rigid cellular foam of Vermiculite lamellae made by drying the frothy mass formed when an aqueous suspension is gasified.