Thermally reversible covalently bonded linear polymers prepared from a dihalide monomer and a salt of dicyclopentadiene dicarboxylic acid

Investigation of thermo-reversibility of polymer crosslinked by reversible covalent bonds through torque measurement

“…Reversible crosslinked brominated butyl rubber (BIIR) was used as a model, which was crosslinked by sodium dicyclopentadiene dicarboxylate through esterification, as shown in Scheme 1. Such esterification crosslinking of halogenated polymer was intensively investigated previously [11][12][13][14]. The results presented in the current paper indicate that the torque measurement provides a simple, sensitive and reliable method to acquire information on the thermo-reversibility of crosslinked polymer and the efficiency of antioxidant to maintain reversibility.…”

“…Both of these polymers showed thermoreversible crosslinking behavior due to thermo-reversible dimerization of the side CPD groups. Following Kennedy's work, thermo-reversible crosslinked polyphosphazene [10] and many other reversible crosslinked polymeric elastomers were reported in the literature [11][12][13][14][15]. DCPD derivative was also employed in making thermally re-mendable polyester [5].…”

Click Chemistry with Cyclopentadiene

“…Heating to 215 °C led to the thermal dissociation of the dicyclopentadiene cross-linked networks and regeneration of the cyclopentadienylated monomers. Ruckstein and Chen studied the thermal reversibility of chlorinated polymers cross-linked through dicyclopentadiene carboxylates (Thiele’s acid). − Thermally reversible dicyclopentadiene cross-linked networks have potential application as self-healing materials. , The Miura group showed that treating cyclopentadienylated polymers with sodium metal prevented cross-linking by converting the cyclopentadienes to the inert sodium cyclopentadienide species …”

Mendable polymers

“…CP derivatives have been employed as cross-linkers for a number of polymers, particularly chlorine-containing polymers, and several patents have been issued. Poly(vinyl chloride) (PVC), polychloroprene, polyepichlorohydrin (PECH), and polychloromethylstyrene (PCMS) have been cross-linked by reacting them with cyclopentadienyl sodium or lithium salts [39][40][41] or dicyclopentadiene dicarboxylic acid (Thiele's acid); [42][43][44] isobutylene-isoprene and ethylene-propylene rubbers have been cross-linked by reacting them with dimethylcyclopentadienylaluminium; 45,46 and poly(dichlorophosphazene) has been cross-linked by reaction with sodium cyclopentadienylethoxide or its dimer. 47 DCP derivatives have Fig.…”