Novel imido/hydroxylate organosilicon copolymers

A process for the preparation of an imido copolymer comprising reacting

• (i) an imido monomer selected from the group consisting of:
• (ia) an oligoimide having the structural formula:
• ##STR16## in which D represents a divalent radical selected from the group consisting of the radicals of the structural formulae:
• ##STR17## in which Y and Y', which are identical or different, each represent H, CH.sub.3 or CL and m is equal to 0 or 1, the symbol A represents an organic radical of valency n, which contains up to 50 carbon atoms, and n represents a number equal to at least 1.5 and equal to at most 5;
• (ib) a mixture of an oligoimide having the structural formula (I):
• ##STR18## in which D, A and n are as defined above, with a polyamine of the structural formula (II):
• G(NH.sub.2).sub.z (II)
• in which G is an organic radical of valency z and z is an integer equal to at least 2;
• and
• (ic) the product of reaction between said oligoimide (I) and said polyamine (II);
• and
• (ii) an organosilicon comonomer comprising at least one hydroxyl group directly bonded to a silicon atom thereof,
• with said reacting occurring in the presence of a catalytic amount of an imidazole (iii) at a temperature ranging from about 50.degree. C. to ranging from about 50.degree. C. to 300.degree. C. 300.degree. C.