Extruded foam product with 134a and alcohol blowing agent

A method for making extruded foam products comprising:

• a) heating to a first temperature a resin mixture comprising an alkenyl aromatic polymer and optional additives thereby producing a plastified resin mixture,
• b) thoroughly mixing with the resin mixture a blowing agent consisting of 134a 1,1,1,2-tetrafluoroethane and an alcohol under a first pressure and under conditions to prevent foaming thereby producing a foamable gel,
• c) cooling the foamable gel to a second temperature and extruding the formable gel into a second pressure less than the first pressure thereby causing the foaming of the gel and formation of an extruded foam product.