A method for the production of gleichmaessigen copolymers of acrylonitrile and aromatic olefins, resulting copolymers and those containing polyblends

摘要

Copolymers of 50 - 95 (pref. 86-93) mole % acrylonitrile with =1 conjugated aromatic olefin (I) with greater reaction speed, such that monomer proportionation is uniform along the chain length, are prepd. by polymsn. in aq. suspension, using hydroxyethyl cellulose (II) or polyvinylpyrrolidone (III) as suspending agents and by dosing the olefin to the reaction mixt. at a rate linearly proportional to the polymsn. speed of the acrylonitrile portion. (I) is acenaphthylene, indene, coumarone or Ar-C(R)=CH2 (where R is CH3 or H; Ar is aromatic (un) substd. residue with =3 rings contg. =4C in substituents). (I) is pref. styrene or alpha-methyl styrene. (II) has a M.S. value, (mole ethylene oxide combined per mole cellulose) of 1.5-3.5, pref. 2-3.5, a D.S. value, (number of OH gps. substd. per anhydroglucose unit), of 1-3.0, pref. 1.5 - 3.0, and a Brookfield viscosity, (as 1% aq. soln. at 25 degrees C), of 500 - 5000, pref. 1000-3000 cP; and (III) has Fikentscher K value 60, pref. =80. The copolymers are used as moulding cpds. alone or mixed with up to equal wt. of a polydiene rubber. The uniform spread of monomer components along the chain minimises disadvantages of block copolymers, esp. where acrylonitrile blocks are terminal. The suspending agents avoid generation of oversize particles which hinder uniformity and clarity of the mouldings.