Mesogen-silicon compound (co)polymer and thermoplastic elastomer

A mesogenic silicon compound (co)polymer represented by the general formula (1) and having a number average molecular weight of 1,000 to 500,000,

• wherein Ar is a mesogenic group selected from the following structures:
• a is a positive number of 0.5 to 1, b is a number of 0 to 0.5, with the proviso that a and b represent a proportion in number of relevant repeating units to the sum of all repeating units in the molecule, respectively, and a+b=1, a repetition number or degree of polymerization (designated a′) of silarylene-silalkylenesiloxane units [—Si(R1)2—Ar—Si(R1)2—C2H4—Si(R1)2—Ar—Si(R1)2—C2H4—Si(R1)2—Ar—Si(R1)2—O—] in the main chain is an integer of the order of 5 to 1,000, a repetition number or degree of polymerization (designated b′) of silarylenesiloxane units [—Si(R1)2—Ar—Si(R1)2—O—] in the main chain is an integer of the order of 0 to 100, and the total number of repeating units or degree of polymerization (designated a′+b′) of the overall main chain is an integer of the order of 10 to 1,000, R1 is independently a C1-C8 monovalent hydrocarbon group free of aliphatic unsaturation, and R2 is independently hydrogen, —Si(CH3)3, —Si(CH3)2(OH), —Si(CH3)2(CH═CH2) or —Si(CH3)2(CH2—CH═CH2).