| 摘要 |
<p>Method comprises prepolymerising a mixt. of styrene, methyl methacrylate (MMA) and synthetic rubber. The prepolymer is then copolymerised in aq. suspension in the presence of an initiator and a stabiliser. The prepolymerisation and suspension copolymerisation are carried out using a mixt. of diacyl peroxides of 3-12C aliphatic acids as initiator. The peroxide mixt. contains 2-8 pts. diacyl peroxides of 3-5C aliphatic acids (I), 80-89 pts. wt. diacyl peroxides of 6-9C aliphatic acids (II) and 7-14 pts. wt. diacyl peroxides of 10-12C aliphatic acids (III). The initiator mixt. allows prepolymerisation and copolymerisation to be carried out without using molecular weight regulator giving polymers with improved physical properties, esp. impact strength, and transparency. Less discolouration of the polymer takes place than in previous materials, so that optical brighteners are not generally necessary.</p> |
