| 摘要 |
The present invention is a process to make a composition comprising a block copolymer A-B and optionally a monovinylaromatic polymer, said process comprising :
a) forming a mixture comprising:
one or more cyclic component polymerizable by ring-opening polymerization (ROP) dispersed in at least one monovinylaromatic monomer,
optionally a rubber dissolved in the monovinylaromatic monomer,
b) contacting the mixture of step a) with a mixture of b1 and b2 such that :
b1) is M[N(SiR 8 3 ) 2 ] x in which M is a metal, R 8 is an hydrocarbon group and x is the valency of the metal M, or
a metal alkoxide M(OR 9 ) x in which M is a metal, R 9 is an hydrocarbon group and x is the valency of the metal M,
or a mixture thereof,
or a single-site metal catalyst component based upon a bulky ²-diiminate ligands (BDI), represented by the following general formula:
wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are each independently selected from hydrogen, unsubstituted or substituted hydrocarbyl, or inert functional group and wherein two or more of said groups can be linked together to form one or more rings, wherein X is an hydrocarbyl radical having from 1 to 12 carbon atoms, an alkoxide group OR*, an amido group NR** 2 or a borohydride group (BH 4 ).
b2) a functional alcohol containing, besides its -OH function, another functionality Y enabling the growth or the grafting of a polyvinylaromatic, at conditions effective to produce by ROP of the cyclic component a block polymer A, having an -OH end and another function Y, dispersed in the monovinylaromatic monomer,
c) polymerizing the solution obtained at step b) optionally in the presence of a free radical initiator, optionally in the presence of chain transfer agents, at conditions effective to produce:
a monovinylaromatic block polymer B linked to the block polymer A by the aforementioned functionality Y such that H-A-O-R-Y-B or H-A-O-R-B-Y (referred in both cases as A-B to simplify) in which R is a linking group,
optionally a monovinylaromatic polymer,
d) optionally degassing the product of step c) to separate the optional unpolymerized monomers and comonomers and recovering optionally a composition comprising at least the block copolymer A-B, optionally a monovinylaromatic polymer and optionally a rubber. At step b2) advantageously the -OH function acts as the chain transfer agent during the ROP catalytic process. |
