The thermally controlled molecular disassembly properties of a polymer network via the incorporation of one sterically hindered urea linkage

Crosslinked polymer networks are excellent materials for multiple applications. However, while their crosslinked structure gives the polymer networks many positive attributes, it also makes the polymer essentially intractable after the covalent crosslinks have formed. Therefore, it is exceedingly difficult to reprocess polymer networks once crosslinked without exposure to extreme degradation conditions. In our earlier work, we were able to create a crosslinked network that could show controlled disassembly upon stimulus. Previously, it was found that controlled network disassembly could be invoked by the incorporation of two sterically hindered urea linkages into each crosslinker of the polymer network. This work describes the reworkable behavior of similar crosslinkers but instead of having two sterically hindered urea linkages the crosslinkers only contain one such linkage. The behavior of the one sterically hindered urea linkage system will then be compared to the two urea linkage system. (C) 2002 Published by Elsevier Science Ltd.