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As a representative single component epoxy resin, diglycidyl ether of bisphenol A resin (DGEBA) is the most widely used matrix in adhesives. However, challenges are still remained including high curing temperature and short shelf life. Herein, bisphenol A (BPA), Tetrachlorobisphenol A (TCBPA), and Tetrabromobisphenol A (TBBPA) as latent curing agents and imidazole as accelerator were used in adhesives. Curing kinetics was studied by non-isothermal DSC, using a model-fitting Malek approach and a model-free advanced isoconversional method of Vyazovkin. Results indicated that curing temperature of EP-BPA, EP-TCBPA, and EP-TBBPA was reduced to 126 ℃, 94 ℃, and 106 ℃, respectively. Storage stability evaluated by DSC indicated the shelf life was up to five months. After curing, molecular weights of the as-prepared linear polymers (EP-BPA, EP-TCBPA, and EP-TBBPA) were 33,822 g/mol, 14,913 g/mol, and 18,846 g/mol, and their tensile strength and shear strength were more than 40.06 MPa and 13.64 MPa, respectively.

Preparing low-flammable biobased epoxy resins with a high glass transition temperature (Tg) and excellent mechanical properties is significant for the rapid growing electronics and microelectronics industry. In this research, a resveratrol-based epoxy resin (REEP) with well-designed chemical structures possessing trifunctional epoxy groups and rigid conjugate structures was prepared through the one-pot method and was then cured by methyl hexahydrophthalic anhydride (MeHHPA). The conventional petroleum-based epoxy resin (DGEBA) was cured by the same kind of curing agent. Results showed that Tg of REEP/MeHHPA was up to 210.8 °C, much higher than that of DGEBA/MeHHPA (only 146.5 °C). The tensile strength and modulus of REEP/MeHHPA were 73.5 MPa and 3.0 GPa, respectively. More importantly, REEP/MeHHPA exhibited exceptional low permittivity (about 3.5) and low flammability with high char yield of 19.0% (800 °C). Therefore, the resveratrol-based epoxy resin could be a promising candidate for DGEBA and has great potential application in electronics and microelectronics industry.

In this work, two types of rigid-flexible integrated epoxy resins, diglycidyl ether of eugenol-2-mercaptoethanol (DGEEM) and diglycidyl ether of vanillic alcohol (DGEVA), which possess similar rigid methoxy-substituted aromatic structures and different soft aliphatic chains in length, were prepared. Micro-morphology structures were tested by AFM, AFM nanomechanical mapping, and AFM-IR. Macro-properties were respectively characterized by tensile test and shape memory test. Results showed that a series of tunable micro-morphology structures including hard-phase-rich sea-island structure, bi-continuous structure, and soft-phase-rich sea-island structure were explored after cured with 4,4-methylenedianiline. Moreover, the shape memory mechanism for these SMEPs was concluded: phase separation structures are the base of these SMEPs, and soft phase acts as switching segments, which contributes to shape memory strain of the SMEPs. The optimal designed SMEPs with bi-continuous phase structure was prepared from this mechanism, which exhibit good mechanical properties and excellent shape memory performance.