Biomass benzoxazine-based shape memory resin, preparation method therefor, and application thereof
A biomass benzoxazine-based shape memory resin, a preparation method therefor, and an application thereof. The method includes: using biomass furfuryl amine, vanillic aldehyde, and paraformaldehyde as raw materials; obtaining an aldehyde group-containing biomass benzoxazine monomer by means of a heating reaction; mixing the aldehyde group-containing biomass benzoxazine monomer with polyether amine, and obtaining a Schiff base biomass benzoxazine monomer by means of a coupling reaction; and curing the Schiff base biomass benzoxazine monomer to obtain the biomass benzoxazine resin having a shape memory function. The benzoxazine-based shape memory resin has excellent thermal performance, high tensile modulus, high strength; an original shape can be permanently changed according to needs, the defect that traditional cross-linked polymers cannot be reprocessed after being formed is overcome, a recovery function under the condition of heating stimulation achieved, an application range of a shape memory polymer widened due to excellent thermal performance and mechanical performance.
1. A method of preparing a shape memory bio-based benzoxazine resin, comprising the following steps:
(1) heating and reacting furfurylamine, a formaldehyde compound and vanillin, recrystallizing to obtain a bio-based benzoxazine monomer containing aldehyde group;
(2) conducting a coupling reaction of bio-based benzoxazine monomer containing aldehyde group and polyetheramine to obtain a Schiff base benzoxazine monomer; and
(3) curing the Schiff base benzoxazine monomer to obtain the shape memory bio-based benzoxazine resin.
2. The method of claim 1 , wherein the step (1) comprises: stirring a mixture of furfurylamine and the formaldehyde compound at room temperature, and adding vanillin into the mixture of furfurylamine and the formaldehyde compound; the formaldehyde compound is formaldehyde or paraformaldehyde; and a molar ratio of furfurylamine, the formaldehyde compound and vanillin is 100:(200-220):100.
3. The method of claim 1 , wherein the step (1) is conducted at 80° C. to 90° C. for 4 hours to 6 hours, and the bio-based benzoxazine monomer containing aldehyde group is recrystallized in ethanol.
4. The method of claim 1 , wherein in the step (2), the coupling reaction is conducted at 125° C. to 130° C. for 1 hour to 2 hours without a solvent in both synthesis and purification processes.
5. The method of claim 1 , wherein in the step (2), a molar ratio of bio-based benzoxazine monomer containing aldehyde group and polyetheramine is 100:50.
6. The method of claim 1 , wherein in the step (3), the Schiff base benzoxazine monomer is degassed and then cured at 150° C. to 240° C. for 10 hours to 24 hours.
7. A shape memory bio-based benzoxazine resin preparing according to the method of claim 1 .
8. The method of claim 1 , further comprising:
bending the shape memory bio-based benzoxazine resin from an original shape into a changed shape and heating the shape memory bio-based benzoxazine resin at a deformation temperature;
cooling to room temperature to obtain the shape memory bio-based benzoxazine resin with the change shape; and
heating the shape memory bio-based benzoxazine resin with the change shape at the deformation temperature again to return the shape memory bio-based benzoxazine resin to the original shape.
9. The method of claim 8 , wherein the deformation temperature ranges from Tg+10° C. to Tg+20° C., and Tg is a glass transition temperature of the shape memory bio-based benzoxazine resin.
10. The method of claim 8 , wherein the shape memory bio-based benzoxazine resin is heated 290° C. to 300° C. for 20 seconds to 30 seconds.