Poly(arylene sulfide) copolymer

A process for preparing a poly(arylene sulfide) (PAS) copolymer (P) comprising blending at a temperature of at least Tm+10° C. a reaction mixture comprising:

• at least one poly(arylene sulfide) (PAS) polymer having a weight-average molecular weight (Mw) of at least 40,000 g/mol as determined by gel permeation chromatography;
• and
• at least one polyorganosiloxane (POS) macromer having epoxy groups at each end of its chain and having a weight-average molecular weight (Mw) of at most 5,000 g/mol as determined by gel permeation chromatography,
• wherein:
• Tm is the melting point of the reaction mixture;
• the weight ratio between the PAS polymer and the POS macromer is from 95:5 to 99.5:0.5;
• and
• the process is carried out in the absence of an added solvent or in the presence of an amount of less than 2 wt. % of the added solvent based on the total weight of the reaction mixture.