A molding composition including at least one semi-crystalline polyamide derived from the polyaddition of a) at least one polyamide prepolymer bearing n identical functions X chosen from carboxyl, amine and hydroxyl, and of b) at least one non-polymeric reactive extender bearing two identical functions Y that are reactive with said functions X with n ranging from 1 to 3, the polyamide and prepolymer a) including 55 mol % to 95 mol % of amide units A, 5 mol %-45 mol % of amide units B with A corresponding to x.T in which x is a linear aliphatic C9-C18 diamine and B corresponding to x.T in which x may be B1): specific branched aliphatic diamine dependent on x or B2): MXD or B3): linear aliphatic diamine which depends on x, the polyamide having a Tg of at least 90 C. and a Tm of less than or equal to 280 C.

A liquid crystal polymer, composition, liquid crystal polymer film, laminated material and method of forming liquid crystal polymer film are provided. The liquid crystal polymer includes a first repeating unit, a second repeating unit, a third repeating unit, a fourth repeating unit, and a fifth repeating unit. The first repeating unit has a structure of Formula (I), the second repeating unit has a structure of Formula (II), the third repeating unit has a structure of Formula (III), the fourth repeating unit has a structure of Formula (IV), and the fifth repeating unit has a structure of Formula (V), a structure of Formula (VI), or a structure of Formula (VII) ##STR00001## wherein A.sup.1, A.sup.2, A.sup.3, A.sup.4, X.sup.1, Z.sup.1, R.sup.1, R.sup.2, R.sup.3 and Q are as defined in the specification.

A polymer film including a silsesquioxane polymer, in which the polymer film has a dielectric loss tangent of 0.01 or less, and applications thereof.

A polymer film including a polymer, in which the polymer film has an elastic modulus of 10 MPa or less at 160 C., an elastic modulus of 0.1 MPa or more at 260 C., an equilibrium moisture absorptivity of 2.5% by mass or less at 85 C. and a relative humidity of 85%, and a dielectric loss tangent of 0.01 or less; a laminate including a layer B containing a polymer, in which the layer B has an elastic modulus of 10 MPa or less at 160 C. and an elastic modulus of 0.1 MPa or more at 260 C., and the laminate has an equilibrium moisture absorptivity of 2.5% by mass or less at 85 C. and a relative humidity of 85% and a dielectric loss tangent of 0.01 or less; and a metallized laminate including the polymer film or the laminate and a metal layer or a metal wire.

A composition including at least one polyamide polymer obtained from at least one reactive polyamide prepolymer including at least one chain extender (PA.sub.1-All.sub.1-PA.sub.1), the polyamide polymer being prepared at a temperature T.sub.1 no lower than the temperature melting temperature or glass transition temperature of the polymer and having a mean molecular weight Mn.sub.1. The composition has a melt viscosity which can be modulated according to the temperature to which the composition is exposed, wherein the temperature is between T.sub.2 and T.sub.3, T.sub.2 and T.sub.3 being higher than T.sub.1, and the melt viscosity .sub.2 or .sub.3 observed at the temperature T.sub.2 or T.sub.3, respectively, being lower than the melt viscosity .sub.2 or .sub.3 of the polyamide polymer, which does not include a chain extender and has the same mean molecular weight Mn.sub.1(PA.sub.1) observed at the same temperature T.sub.2 or T.sub.3. The composition includes one or more polyamides.

Provided is an ester-amide multi-block copolymer represented by formula (1), which comprises a block containing a polyester and a block containing a polyamide obtained through ring opening polymerization of a cyclic lactam. (R1 and R2 each denote a hydrogen atom or a substituent group-containing alkyl chain having 1-20 carbon atoms, and R3 denotes a hydrogen atom or a substituent group-containing alkyl chain having 1-10 carbon atoms. In addition, R4 is an aromatic hydrocarbon chain that does, or does not, contain a heteroatom or an aliphatic hydrocarbon chain that does, or does not, contain a hetero atom. Y is NH, O or S. Furthermore, m denotes an integer between 1 and 60, n denotes an integer between 1 and 120, 1 denotes an integer between 2 and 100, and x denotes an integer between 1 and 11).

A liquid crystal polymer, composition, liquid crystal polymer film, laminated material and method of forming liquid crystal polymer film are provided. The liquid crystal polymer includes a first repeating unit, a second repeating unit, a third repeating unit, and a fourth repeating unit. The first repeating unit has a structure of Formula (I), the second repeating unit has a structure of Formula (II), the third repeating unit has a structure of Formula (III), and the fourth repeating unit has a structure of Formula (IV), a structure of Formula (V) or a structure of Formula (VI) ##STR00001##
wherein A.sup.1, A.sup.2, A.sup.3, Z.sup.1, R.sup.1, R.sup.2, R.sup.3 and Q are as defined in the specification.