Synthesis And Characterization Of Bio-based Thermosetting Resin

In recent time, due to the pressure on serious environmental pollution and diminishing petroleum oil resource, more and more attention has been directed to the research and development on bio-based materials. Up to now, a great quality of bio-based polymeric materials, such as polylactic acid, poly (hydroxyalkanoates) and polymers derived from starch have been commericalized. However, the designs of bio-based materials are always passive. The bio-based materials were directly transformed from biomass but lots of them were useless. In our work, the biomass was transformed to materials according to its molecular structure. In this way, the structural features of the biomass can get the biggest exercise.1. Diglycidyl dehydroabietylamine (DGDHAA) was synthesized by reacted with epichlorohydrin. Their chemical structures were confirmed in detail by Fourier Transform Infrared Spectra (FT-IR) and Nuclear Magnetic Resonance (1H-NMR and HSQC). The curing reactions of these synthesized epoxies with hexahydrophthalic anhydride were studied by Differential Scanning Calorimeter (DSC). The mechanical properties and thermal stability of the cured epoxies were investigated by Universal Mechanical Testing Machine, Dynamic Mechanical Analysis (DMA) and Thermogravimetric Analyzer (TGA), respectively.The results indicated that the bulky fused diterpene structure in dehydroabietylamine lead to a weaker molecular motion ability. The activation energy value of DGDHAA was61.3kJ· mol-1, which mean it need higher temperature when cured the DGDHAA. The dynamic mechanical analysis howed that the big diterpene structure with three rings in DGDHAA could lead to a higher glass transition temperature as170℃。And mechanical property study showed the DGDHAA had weaker tensile and flextural properties47MPa and68MPa, respectively.2. Isosorbide was used to synthesize the isosorbide based epoxy monomer (ISE) and isosorbide based diamine (ISA) as curing agent. ISE and ISA were used proportionally to cure the isosorbide epoxy monomer to get a fully isosorbide-based epoxy material, which can be used as a shape memory material(isosorbide-based shape memory material, ISSMM).The chemical structures of ISE and ISA were confirmed in detail by Nuclear Magnetic Resonance. To investigate the shape-memory properties of the ISSMM were tested using the U-type shape-memory test. The Tg values were obtained from DSC. U-type shape-memory test showed that the ISSMM had a nearly100%shape fixity and100%shape recovery. When Diglycidyl ether of bisphenol A (DGEBA) was added to the system to replace parts of ISE, the cured products had a higher Tg, but their shape-memory properties were poor. That is because the bisphenol A was a rigid structure, which make the materials have an energy loss in the process of deformation. The thermomechanical cycles also confirm the ISSMM showed excellent shape memory properties. The TGA curve showed that the the temperatures at which5%weight losses (T5%)were306℃.