Renewable Castor‐Oil‐based Waterborne Polyurethane Networks: Simultaneously Showing High Strength, Self‐Healing, Processability and Tunable Multishape Memory

Abstract

Materials with multifunctionality or multiresponsiveness, especially polymers derived from green, renewable precursors, have recently attracted significant attention resulting from their technological impact. Nowadays, vegetable‐oil‐based waterborne polyurethanes (WPUs) are widely used in various fields, while strategies for simultaneous realization of their self‐healing, reprocessing, shape memory as well as high mechanical properties are still highly anticipated. We report development of a multifunctional castor‐oil‐based waterborne polyurethane with high strength using controlled amounts of dithiodiphenylamine. The polymer networks possessed high tensile strength up to 38 MPa as well as excellent self‐healing efficiency. Moreover, the WPU film exhibited a maximum recovery of 100 % of the original mechanical properties after reprocessing four times. The broad glass‐transition temperature of the samples endowed the films with a versatile shape‐memory effect, including a dual‐to‐quadruple shape‐memory effect.

The Prospering of Macromolecular Materials Based on Plant Oils within the Blooming Field of Polymers from Renewable Resources

“…A waterborne polyurethane network was synthesized using castor oil, dimethylolbutanoic acid, and isophorone diisocyanate and its structural strength could be tailored by the incorporation of different amounts of octahydro-2,5-pentalenediol [ 64 ]. Furthermore, the same research group prepared high strength self-healing multi-shape memory waterborne polyurethane networks by introducing controlled amounts of dithiodiphenylamine to the castor oil-based polymer chains [ 65 ]. The use of castor oil as a polyol in combination with the previously mentioned sulfur crosslinking strategy was employed to produce high strength vulcanized polyurethane interpenetrating polymer networks.…”

Long-chain polyamide covalent adaptable networks based on renewable ethylene brassylate and disulfide exchange

“…Seeking for a simpler and more sustainable alternative towards longchain PA CANs, we focused on disulfides as an intrinsically reactive bond, 31,32 that can be activated under mild conditions. 33 Disulfides have been incorporated into urea, 34 urethane, 23,35,36 ester 4,37 and epoxy-based [38][39][40] networks, and have been combined with renewable building blocks such as diacids (succinic, adipic, sebacic), 4 castor oil 24,41 and epoxidized soybean oil, 42 leading to high-performance thermosets with impressive results regarding the ease of reprocessability and retainment of the mechanical properties after several reprocessing cycles.…”

Flame Retardant Modified Bio‐Based Waterborne Polyurethane Dispersions Derived from Castor Oil and Soy Polyol

“…[ 18 ] Zhang et al. [ 19 ] introduced reversible covalent disulfide bonds of dithiophenylamine into castor oil‐based WPU. The WPU networks possessed high strength up to 38 MPa, self‐healing, processability, and dual‐to quadruple shape memory.…”