Bio-based Polyurethane Based on a Dynamic Covalent Network with Damage Tolerance for Controlled Release of Fertilizers

Abstract

Bio-based polyurethanes are promising for the controlled release of nutrients and fertilizers, but their toughness and plasticity need to be improved. We developed a smooth, dense, elastic, and indestructible bio-based polyurethane (BPU) coating with a nutrient controlled release ∼150% superior, a tensile strength ∼300% higher, and a toughness ∼1200% higher than those for the original BPU coating. Through a one-step reaction of soybean oil polyols (accounting for more than 60%), isocyanate, and benzil dioxime, the dynamic covalent network based on oxime-carbamate replaces part of irreversible covalent cross-linking. The dynamic fracture-bonding reaction in the modified coating BPU can effectively promote the hydrogen bond recombination and oxime-carbamate chain migration in the coating process, which avoids the structural defects caused by coating tear and fertilizer collision. This work provides a simple and versatile strategy for building controlled-release fertilizer coatings.

Synthesis of Bio-Based Thermoset Mixture Composed of Methacrylated Rapeseed Oil and Methacrylated Methyl Lactate: One-Pot Synthesis Using Formed Methacrylic Acid as a Continual Reactant

“…Three-dimensional printing technologies, such as stereolithography (SLA), can incorporate these precursors into their products to increase their bio-content [13]. Several coating applications may benefit from the properties these materials can provide, namely paper coating or incorporation into controlled-released fertilizers (CRFs) [14,15].…”

Vanillin-Based Degradable Polyurethane Thermosets Demonstrating High Bio-Content and Mechanical Properties

“…(a) Stress–strain curves of VBD-TMP x and (b) mechanical performance of VBD-TMP 60 in this work compared with some biorenewable crosslinked polyurethanes in other research studies and commercial nonrenewable crosslinked polyurethanes. ,,,,,− …”

“…Therefore, bio-based thermosetting polyurethanes with different mechanical properties can be facilely prepared by tuning the content of crosslinker TMP. Within the context of biorenewable crosslinked polyurethanes, these VBD-TMP x lie at the high end of mechanical performances (Figure b). ,,,,,− They offer comparable tensile strengths and elongation at break values, but stand out in terms of their high bio-contents and degradability. It is also noteworthy that the stress–strain profiles for VBD-TMP 60 are comparable to or better than some of the commercial nonrenewable crosslinked polyurethanes, such as the Durethane R series and Desmodur MP-101 (Figure b).…”

Recent Advances in Tailored Fabrication and Properties of Biobased Self-Healing Polyurethane

“…The excellent properties of the coatings were attributed to the cross-linking modification of polyols, the ratio of soft and hard segments, and the reversible reaction of disulfide bonds. In another study, 96 Yu et al successfully prepared CRF coatings using soybean oil polyol, benzil dioxime, and PAPI as raw materials. The hydrogen bond interaction and oxime-urethane bonds facilitated the self-healing of the coatings under heat, resolving the problem of accelerated fertilizer release caused by micropores during the curing of the coating.…”