Functional dendritic curing agent for epoxy resin: Processing, mechanical performance and curing/toughening mechanism

A high performance copolymer was prepared by using epoxy (EP) resin as matrix and 3,10,17,24‐tetra‐aminoethoxy lead phthalocyanine (APbPc) as additive with dicyandiamide as curing agent. Fourier‐transform infrared spectroscopy, dynamic mechanical analysis (DMA), differential scanning calorimetric analysis (DSC), and thermogravimetric analysis (TGA) were used to study the curing behavior, curing kinetics, dynamic mechanical properties, impact and tensile strength, and thermal stability of EP/APbPc blends. The experimental results show that APbPc, as a synergistic curing agent, can effectively reduce the curing temperature of epoxy resin. The curing kinetics of the copolymer was investigated by non‐isothermal DSC to determine kinetic data and measurement of the activation energy. DMA, impact, and tensile strength tests proved that phthalocyanine can significantly improve the toughness and stiffness of epoxy resin. Highest values were seen on the 20 wt% loading of APbPc in the copolymers, energy storage modulus, and impact strength increased respectively 388.46 MPa and 3.6 kJ/m2, Tg decreased 19.46°C. TGA curves indicated that the cured copolymers also exhibit excellent thermal properties.

Section: Resultsmentioning

confidence: 95%

“…Adding the second component can effectively improve the toughness of epoxy resin, such as nano‐inorganic particles, rubber elastomers, and thermoplastic polymers . It needs to solve the agglomeration of nanoparticles in the matrix and the interfacial compatibility with the matrix.…”

Section: Introductionmentioning

confidence: 99%

Studies on the curing behavior, thermal, and mechanical properties of epoxy resin‐co‐amine‐functionalized lead phthalocyanine

Gao

et al. 2020

“…The grafting of polyol onto PU using a diisocyanate compound has already been reported in the literature for the improvement of water compatibility of PU surface . The reactive benzimidazole could be easily grafted onto PU via MDI because imidazole was frequently used as a protecting group for isocyanate group . In contrast, recycled polyol and benzimidazole were not attached to PU in the control CPB series to compare with the PB series with respect to the thermal phase transition, shape recovery capability, tensile strength, flexibility at very low temperature, and antifungal activity.…”

Section: Resultsmentioning

confidence: 99%

Application of recycled polyol and benzimidazole to the enhancement of antifungal activity of polyurethane

Chung

Lee

Choi

et al. 2018

Recycled polyol and benzimidazole were both grafted onto polyurethane (PU) to enhance the surface hydrophilicity and antifungal activity, respectively. The two grafted groups affected the viscosity, crosslink density, soft segment glass transition, breaking stress, flexibility at freezing temperature, shape recovery at 210 8C, surface hydrophilicity, and antifungal activity. The glass transition temperature increased from 267.5 8C for plain PU up to 260.8 8C after the grafting of polyol. The breaking stress and shape recovery of the grafted PU increased up to 425% and 200%, respectively, relative to plain PU because of the chemical linking by the grafted polyol. The hydrophilicity of PU, evaluated by the water contact angle and water swelling ratio, increased with increasing polyol content. A PU sample demonstrated excellent low-temperature flexibility in comparison to plain PU and control sample. Finally, the PUs modified with grafted polyol and benzimidazole completely suppressed fungal growth. V C 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018, 135, 46600.

“…There are many materials used for epoxy toughening. [3][4][5][6][7][8] Toughening epoxy resin with CTBN is a traditional method. The principle is that the ''island structure'' would be formed during the curing process of epoxy resin, which improves the toughness of epoxy resin and meets the requirements of high impact strength and toughness.…”

Section: Introductionmentioning

confidence: 99%

Synergistic toughening of epoxy resin byCTBNandCM‐β‐CD

Yin

Xie

Liu

et al. 2021

Carboxymethyl-β-cyclodextrin (CM-β-CD) and carboxyl terminated liquid nitrile rubber (CTBN) were used as binary component fillers in toughening the epoxy resin (E-54). For a single component filler system, the addition of CTBN resulted in significantly improved fracture toughness but reduction of glass transition temperature (T g ) and modulus of epoxy resin. On the other hand, the addition of CM-β-CD resulted in a modest increase in modulus and T g , and significant improvement in toughness. This work provides a promising route of nanocomposites with excellent toughness. Besides the mechanism of synergistic toughening in this project was explained, and the major toughening mechanisms were attributed to interfacial micro-cracks, energy dissipation of CM-β-CD. This work gives us a further understanding of the modification effect of β-CD.