Polymerization process and polymers produced thereby

DETAILED DESCRIPTION We claim: 1.
A method for the production of a polymer or a copolymer, including an oligomer, by free radical polymerization of one or more unsaturated monomers comprising heating with the monomer a compound according to the general formula (I) ##STR9## wherein X represents a group having at least one carbon atom and is such that the free radical X.
sup.
.
derived from X is capable of initiating polymerization of the unsaturated monomer by free radical polymerisation and the radical functionality resides in a carbon atom, R.
sup.
1, R.
sup.
2, R.
sup.
5 and R.
sup.
6 represent the same or different straight chain or branched substituted or unsubstituted alkyl groups of a chain length sufficient to provide steric hindrance and weakening of the O--X bond of the compound of formula I, and R.
sup.
3 and R.
sup.
4 represent the same or different straight chain or branched substituted alkyl groups or R.
sup.
3 CNCR.
sup.
4 may be part of a cyclic structure which may have fused with it another saturated or aromatic ring, the cyclic structure or aromatic ring being optionally substituted.
2.
A method according to claim 1 comprising a two stage method for preparing a graft polymer comprising a first stage of forming a polymer backbone with pendant alkoxyamine groups of the general structure of formula I and a second stage of adding a second monomer and heating to form a graft copolymer by controlled growth free radical polymerization initiated by a radical derived from X.
3.
A method according to claim 2 comprising a third stage of adding a third monomer and heating to form a block copolymer with the grafted chains of the graft polymer by controlled growth free radical polymerization initiated by a radical derived from X.
4.
A method according to claim 1 for making a polymer containing an alkoxyamine group comprising copolymerizing two or more monomers wherein at least one of the monomers contains the alkoxyamine group of the general structure of formula I.
5.
A method according to claim 2 in which the second step comprises polymerizing a mixture of two or more monomers to provide a graft copolymer in which the grafted chains are random copolymers