What does the slash in polymer nomenclature, e.g. Acrylates/ Beheneth-25 Methacrylate Copolymer, mean?
Acrylates/Beheneth-25 Methacrylate Copolymer is an INCI name for a copolymer


  … formed from the ester of 2-methylpropenoic acid and docosanol, ethoxylated, 25 mol EO (average molar ratio) and one or more monomers of acrylic acid, methacrylic acid or one of their simple esters


(Source: cosmetics.specialchem.com)

Also known by the trademark Aculyn™ 28.
Dow Chemical provides cumulative MSDS datasheet (pdf) for the entire Aculyn family, so I assume you can use it for your copolymer as well.