(Macromolecules) Robust, Fire-Safe, Monomer-Recovery, Highly Malleable Thermosets from Renewable Bioresources
writer：Sheng Wang, Songqi Ma,* Qiong Li, Wangchao Yuan, Binbo Wang, Jin Zhu*
keywords：malleable thermosets, Schiff base, recycle, vanillin
source：期刊
specific source：Macromolecules
Issue time：2018年
Conventional thermosets are built by nonrenewable fossil resources, and are arduous to be reprocessed, recycled, and reshaped due to their permanent covalent cross-linking, and their flammability makes them unsafe during use. Here, for the first time, we synthesized a novel Schiff base precursor from abundant and renewable lignin derivative vanillin and produced malleable thermosets (Schiff base covalent adaptable networks (CANs)) combining high performance, super-rapid reprocessability, excellent monomer-recovery and arbitrary permanent shape changeability as well as outstanding fire resistance. The Schiff base CANs exhibited high glass transition temperatures of ～178 °C, tensile strength of ～69 MPa, and tensile modulus of ～1925 MPa, and excellent flame retardancy with UL-94 V0 rating and V1 rating and high LOI of ～30 %. Meanwhile, three Schiff base CANs showed high malleability with the activation energy of the bond exchange of 49～81 kJ mol-1 and could be reprocessed in 2～10 min at 180 °C. These Schiff base CANs provide a prime example to foster the development of advanced thermosetting materials from renewable bioresources.