Investigation of novel crosslinking reactions as versatile tool for designing self-healing polymers

Investigation of novel crosslinking reactions as versatile tool for designing self-healing polymers

Michael, P.
Döhler, D.
Binder, W.H.

2013-06-16

In recent times the development of self-healing polymeric materials is focused on investigations of fast and efficient crosslinking processes. These should either be able to form new highly branched networks in order to restore thus the initial material properties or to enhance existing materials in view of their thermomechanical and physicochemical properties. We therefore investigated the copper(I)-catalyzed alkyne-azide "click" cycloaddition reaction (CuAAC) of multivalent polymeric alkynes and azides with respect to crosslinking kinetics, crosslinking efficiencies as well as autocatalytic effects [1-3]. For this purpose a library of several multivalent poly(acrylate)s and poly(isobutylene)s (PIB’s) bearing alkyne respectively azide functionalities were synthesized. An efficient network formation could be observed via in situ rheology measurements within several hours even at room temperature. Moreover a dependency of the network formation rate on the molecular weight and the functional group densities could be proofed. Based on these results we expanded the concept of CuAAC to hyperbranched PIB’s prepared via living carbocationic inimer (initiator-monomer) type polymerization [4] to study the kinetics and autocatalysis of CuAAC in dependency of branching frequency and to improve the resulting network strand densities and therefore the stiffness of the final crosslinked material. Beside this we pursue another intrinsic self-healing approach investigating various mechnochemical concepts based on the autonomous activation of a latent catalyst by external force [5]. On this occasion we prepare a polymer based metal-complexes which are able to trigger crosslinking reactions under applied force.

self-healing polymers
mechanochemistry
copper(I)-alkyne-azide “click” reaction

http://resolver.tudelft.nl/uuid:d82f5d75-5a51-4304-a86a-03bda8eb82df

Conference proceedings

conference paper

(c) 2013 Michael, P.; Döhler, D.; Binder, W.H.