Abstract
This thesis work aim to demonstrate a polymer self-healing concept using hemiacetal ester functions. These functions are known to thermally dissociate into carboxylic acids and vinyl ethers between 100 and 250 °C depending of structures. This property is commonly use to react carboxylic acids “on demand”. This “on demand” reactivity is exploited here for self-healing, by introducing hemiacetal esters into a bio-based epoxidized polymer matrix.An investigation of the hemiacetal ester functions properties made possible the selection a “repairing agent”, based on its dissociation temperature, and demonstrate its capacity to react with epoxy functions. Furthermore, this investigation granted the identification of restrictions dues to this function reactivity, which influenced the polymer matrix choice.A polymer matrix was establish from epoxidized linseed oil by grafting of acrylate functions. This oil was mixed with an adhesion promotor and a reactive diluent before being deposited as a coating on 3003 aluminum alloy and cross-linked under UV. Electrochemical impedance measurements demonstrate interesting barrier properties and a positive impact of the repairing agent under thermal treatment. However, the established matrix do not present enough mobility to repair defects of several microns wide.To solve this difficulty, a polymer network whose flow capacity is based on a hemiacetal ester exchange reaction, highlighted in this manuscript, was established and a rheological study demonstrated its flow ability under thermal treatment.