Abstract: A polymeric foam precursor composition including the following components: (a) a di- or tri-functional (meth)acrylate oligomer (2); (b) a di- or higher-functional thiol compound (3); and (c) a borane compound (4) as initiator. The foam precursor composition can be isocyanate free, and the curing rate is largely moisture independent and can cure at low temperatures, below freezing point.