| abstract |
The present invention relates to polymeric compositions prepared by a process comprising: (a) providing a first reactive composition containing: (i) a polymerization initiator which is capable, upon first activation, of forming two or more radical groups at least one of which is additionally activatable by subsequent activation; (ii) one or more ethylenically unsaturated compounds; and (ii) a crosslinker; (b) subjecting the first reactive composition to a first activation step so that the first reactive composition is polymerized therein to form a crosslinked substrate network containing a covalently bonded free radical initiator, (c) combining the crosslinked substrate network with a second reactive composition containing one or more ethylenically unsaturated compounds; and (d) activating the covalently linked activatable free radical initiator of the crosslinked substrate network so that the second reactive composition is polymerized therein with the crosslinked substrate network to form a grafted polymeric network and a polymer byproduct. Precursors of polymeric compositions, processes for preparing the polymeric compositions and methods of using the polymeric compositions, for example, in medical devices are also provided. |