Thermal and mechanical properties of thiol-ene photocured thermosets containing DOPO-based liquid reactive flame retardant synthesized by metal-free azide-alkyne click reaction

New Horizon in Phospha-Michael Reaction: Ultrafast Double Addition of P–H Bond-Bearing Nucleophiles to Electron-Deficient Triple Bonds and Its Use for Functional Monomer Synthesis and Polymer Modification

“…Due to the presence of aromatic groups in all formulations, bands appearing at around 1600 cm –1 are attributed to carbon–carbon double bond stretching vibrations. The absence of any band at around 1650 and 2550 cm –1 corresponding to allyl and thiol groups, respectively, indicates a high level of a double bond and thiol conversion. ,, We further evaluated the extent of curing by measuring the gel content of the photocured films via 24 h of soxhlet extraction with CHCl 3 (Table ). The base formulation, FR0, has a gel content of 98%.…”

“…In our previous work, we attached the phosphorus-containing compound (i.e., DOPO) to the ACDAE in two steps. First, an azide-functional phosphorus-containing compound was synthesized and then reacted with ACDAE via a metal-free azide-alkyne click reaction . The applied strategy allowed us to produce doubly substituted reactive monomers in a one-pot reaction.…”

Propiolated Castor Oil: A Novel and Highly Versatile Bio-Based Platform for Extremely Fast, Catalyst-, and Solvent-Free Amino-yne Click Reactions

“…42−49 We have demonstrated that diallyl esters of acetylene dicarboxylic acid can be functionalized similarly. 49,50 In light of the studies in the literature and foresights that we have gained with our studies on electron-deficient triple bond-containing monomers, we speculated that the activated triple bond-containing castor oil could be a versatile platform for the synthesis of bio-based functional materials and thermoset polymers. Here, we present the synthesis of propiolated castor oil and demonstrate its subsequent functionalization with a series of primary and secondary amines (Scheme 1).…”

“…Recently, our group has been interested in the metal-free click reactions, modifications, and polymerization of electron-deficient triple bond-containing monomers such as acetylene dicarboxylic acid and its derivatives. − We have shown that polyesters containing acetylene dicarboxylate on their backbone can be easily modified with aza-Michael and thiol-Michael reactions under benign conditions, in the absence of metal catalysts, and in high yields. − We have demonstrated that diallyl esters of acetylene dicarboxylic acid can be functionalized similarly. , In light of the studies in the literature and foresights that we have gained with our studies on electron-deficient triple bond-containing monomers, we speculated that the activated triple bond-containing castor oil could be a versatile platform for the synthesis of bio-based functional materials and thermoset polymers. Here, we present the synthesis of propiolated castor oil and demonstrate its subsequent functionalization with a series of primary and secondary amines (Scheme ).…”

Synthesis of a DOPO Derivative to Improve the Fire Safety and Mechanical Performance of Epoxy Resin

“…[17,18] For example, triazoles were widely used in the preparation of flame retardants due to their high nitrogen content and stable heterocyclic structure. Several DOPO derivatives containing triazoles were designed as flame retardants [19][20][21][22][23][24] and used in EP. In this work, a DOPO derivative containing triazole and bio-based syringaldehyde was prepared.…”