Polyphenylene ether electrical insulation compositions

An electrically insulative, flame retardant, thermoplastic, flexible, halogen-free composition, which comprises;

• (i) 100 parts by weight of a thermoplastic polyphenylene ether resin;
• (ii) 5 to 50 parts by weight of a phenylsiloxane fluid, said phenylsiloxane having a weight average molecular weight within the range of from about 800 to 100,000, said phenylsiloxane consisting essentially of chemically combined units of the formulae:
• (C.sub.6 H.sub.5).sub.2 SiO (a)
• CH.sub.3 (C.sub.6 H.sub.5)SiO and (b)
• (CH.sub.3).sub.2 SiO (c)
• where there is present in the phenylsiloxane fluid from 20 to 40 mole % of (a), or 40 to 80 mole % of (b), and 21 to 79 mole % of the sum of (a)+(b), based on the total moles of (a), (b), and (c);
• and
• (iii) a flexibilizing proportion of an elastomeric block copolymer having a hydrogenated A-B-A' structure, wherein A and A' are polymerized vinyl aromatic hydrocarbon blocks, and B is an ethylene-butylene bock, and
• wherein the block copolymer has a wight average molecular weight of from about 40,000 to 100,00 and the average molecular weight of each block A and ' is independently in the range of about 4,000 to about 15,000, and the weight average molecular weight of the B block is in the range of about 25,000 to about 90,000.