The use of soybean oil or its derivatives to toughen polylactide (PLA) usually leads to limited toughening efficiency, due to the incompatibility between toughening agents and parent PLA. Herein, we report a dynamic vulcanization method to toughen PLA using sebacic acid cured epoxidized soybean oil (VESO), a fully sustainable and biodegradable component. A series of sebacic acid cured epoxidized soybean oil precursors (SEPs) were prepared with different carboxyl/epoxy equivalent ratio (R), which consequently dictates the chemical structure and the morphology of PLA/VESO blends after the dynamic vulcanization. We demonstrated that the chemical structure of VESO plays a critical role in the compatibility, morphology, and toughness of the PLA/VESO blends. By optimizing the R-value, supertoughened PLA blends can be obtained, as evidenced by the significant improvement in the tensile toughness (up to 150.6 MJ/m3) and the impact strength (up to 542.3 J/m). The results of the toughening mechanism from the morphology study confirm that the chemical structure of VESO is the key indicator of the toughening efficiency. For the PLA/VESO blends, at optimized R-value, the fracture energy can be dissipated efficiently through shear yielding of the PLA matrix induced by internal VESO cavitation to achieve supertoughness.

Polymers synthesized directly from plant oils such as castor oil usually exhibit poor mechanical properties and cannot be reprocessed due to the soft, highly cross-linked and permanent cross-linking structures. Herein, we report a novel approach to synthesize high performance and malleable polymer networks, namely poly­(ester amide) vitrimers, from castor oil via melt condensation polymerization with sebacic acid, polyamide 1010 monomer salt and 4-aminophenyl disulfide. 4-Aminophenyl disulfide with excellent thermal stability is applicable for high temperature polymerization and endows the poly­(ester amide) network with malleability. Polyamide 1010 segments introduced by polyamide 1010 monomer salt endow the poly­(ester amide) network with improved and tunable mechanical properties. This investigation demonstrates a new powerful strategy for developing high performance and reprocessable polymer networks from plant oils.

The substitution of petroleum-based self-healing elastomers with biobased counterparts is crucial to the global sustainable development of the rubber industry, which highly depends on the ease of the synthesis procedure. Herein, we show that highly stretchable, recyclable, and self-healable biobased elastomers were synthesized via condensation polymerization of succinic acid, adipic acid, sebacic acid, and 1,4-butanediol in the presence of a small amount of glycerol as a curing agent and 3,3′-dithiodipropionic acid as a dynamic covalent monomer. The macroscopic properties of our elastomers, including thermal, mechanical, stress relaxation, and self-healing performance, were finely regulated via microscopic chemical and topological structure. As such, a highly stretchable (up to ∼1700%), recyclable (almost without degradation of the mechanical performance over several repeats), rapid room temperature self-healable (in 20 min) biobased vitrimeric elastomer was achieved, which is the first aliphatic disulfide metathesis assisted self-healing polymer achieved at such low temperatures. The ease of the polycondensation with which the elastomers can be readily scaled up points to exciting opportunities for sustainable polymers with minimal environmental impact.

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A highly efficient alkenylation reaction of arylglyoxals with 3-vinylindoles catalyzed by chiral calcium phosphate is described. Structurally diverse allylic alcohols bearing indole and carbonyl units are prepared in excellent yields, good diastereoselectivities, and high to excellent enantioselectivities. These products are good building blocks for the synthesis of polysubstituted chiral tetrahydrocarbozol-2-ones. The mechanism study indicates that the most likely role of the catalyst is to activate the hydrate of arylglyoxal and control the stereoselectivity via desymmetric coordination.

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