Simultaneous reinforcement and toughness improvement in an aromatic epoxy network with an aliphatic hyperbranched epoxy modifier

Jin, Qifeng; Misasi, John; Wiggins, Jeffrey S.; Morgan, Sarah E.

doi:10.1016/j.polymer.2015.07.031

Cited by 55 publications

(43 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The fibrils are also found on the fracture surfaces of samples containing 5% HBPEE‐1 and 5% HBPEE‐2. The improvement in toughness can be ascribed to an in situ homogeneous toughening mechanism . In a previous study, molecular simulation and positron annihilation lifetime spectroscopy demonstrated that the addition of hyperbranched modifiers could introduce nano‐sized cavities into cured hybrid systems.…”

Section: Resultsmentioning

confidence: 99%

“…(a), E ′ of hybrids at lower loadings (≤5 wt%) are higher than that of neat BOZ due to the higher average functionality. According to classical theory of rubber elasticity, the crosslinking density of cured BOZ resins can be estimated as follows:

E_{r} = 3 v_{e} italicRT

where v e is the crosslinking density, R is the gas constant (8.314 J K −1 mol −1 ), T is the temperature taken 30 °C above T g and E r is the rubbery storage modulus taken at T . The calculated v e of each cured sample is listed in Table .…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

An investigation of the relationship between the performance of polybenzoxazine and backbone structure of hyperbranched epoxy modifiers

Wang

Liu

et al. 2017

Polymer International

View full text Add to dashboard Cite

Novel hyperbranched polyether epoxies (HBPEEs) with various backbone structures were synthesized using a one‐pot A2 + B3 approach. These highly effective HBPEEs were incorporated into polybenzoxazine (PBOZ) network at various concentrations without cure‐induced phase separation. Effects of backbone structure and loading amount on the curing behavior and mechanical and thermal properties of PBOZ/HBPEE hybrid were investigated. The general trend shows that the impact strength, flexural strength and storage modulus all first increase and then decrease with filler content. For the backbone structure study, HBPEE‐3, which has the highest proportion of benzene rings, can simultaneously improve impact strength, flexural strength and storage modulus. In contrast, HBPEE‐1 and HBPEE‐2, which have fewer benzene rings and smaller intramolecular cavities, perform worse in terms of mechanical and thermal properties. Both backbone structure and loading of HBPEEs play important roles in determining the crosslink density and structures of non‐phase‐separated network. In addition, the simultaneous improvement can be explained by enhanced crosslinking density, structure of modifier, reduced hydrogen bond network and higher fractional free volume according to dynamic mechanical and thermomechanical analyses. © 2017 Society of Chemical Industry

show abstract

Section: Resultsmentioning

confidence: 99%

E_{r} = 3 v_{e} italicRT

Section: Resultsmentioning

confidence: 99%

An investigation of the relationship between the performance of polybenzoxazine and backbone structure of hyperbranched epoxy modifiers

Wang

Liu

et al. 2017

Polymer International

View full text Add to dashboard Cite

show abstract

“…The most effective method to enhance anti‐flaming properties is currently the addition of flame retardants, but most flame retardants have poor compatibility with epoxy resins. This usually negatively impacts the mechanical properties of the resin . Therefore, it is necessary to design a flame retardant with good flame retardancy and good compatibility.…”

Section: Introductionmentioning

confidence: 99%

“…This usually negatively impacts the mechanical properties of the resin. [5][6][7][8][9][10] Therefore, it is necessary to design a flame retardant with good flame retardancy and good compatibility.…”

Section: Introductionmentioning

confidence: 99%

A novel nitrogen, phosphorus, and boron ionic pair compound toward fire safety and mechanical enhancement effect for epoxy resin

Tang

Zhou

2019

Polymers for Advanced Techs

View full text Add to dashboard Cite

In this work, a novel nitrogen, phosphorus and boron ionic pair compound (DTPA[AZB]), composed of a protonated flame retardant (DTPA) 6,6'‐(1,4‐phenylenebis((pyrazin‐2‐ylamino)methylene))bis(dibenzo[c,e][1,2]oxaphosphinine 6‐oxide) and a counter anion alizarin borate (AZB), has been prepared and fully characterized, AZB was synthesized by the reaction of alizarin with boric acid. DTPA was produced in two steps. First, terephthalaldehyde was condensed with aminopyrazine to form the corresponding imine. This was treated with 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) to generate DTPA. Blending with DTPA greatly reduced the flammability of epoxy resin. When the amount of DTPA added was 4%, a modified epoxy resin passed the V‐0 rating and the limiting oxygen index (LOI) reached 32.5%. With the introduction of 3% AZB into the EP/DTPA material, the LOI reached 33.5%. Simultaneously, compared with that of neat EP, the peak heat release rate and smoke production rate for EP/DTPA‐4 was decreased by 24.1% and 40.7%, respectively, and the peak heat release rate and smoke production rate for EP/DTPA[AZB]‐3 was decreased by 32.9% and 43.4%, respectively. The results indicate that AZB and DTPA show good cooperative flame retardant effects. The flame retardancy of the modified epoxy is improved with greater heat release suppression combustion of the resin. A mode of flame retardant action has been proposed based on analysis results from Py‐GC/MS for DTPA, and SEM, IR and Raman for the residual carbon from cone calorimeter and UL‐94 tests, respectively. Importantly, the tensile strength, fexural strength, and fexural modulus of the EP/DTPA[AZB] increased compared with the same properties of neat EP.

show abstract

“…A lack of toughness or distortional behavior of the matrix in particular, is driving much of the current research into more ductile and impact resistant network polymers . Despite being primarily controlled by crosslink density or the chemical structure of the network, additive approaches to improving toughness are common, including ductile and rigid inclusions, interlayers, and nanoadditives to name a few. The primary goal of all these strategies, however, remains the enhancement of toughness or distortional behavior, without compromising other desirable properties such as modulus, strength, or processability …”

Section: Introductionmentioning

confidence: 99%

Synthesis of tri‐aryl ketone amine isomers and their cure with epoxy resins

Reyes

Dao

Vogel

et al. 2019

Polymers for Advanced Techs

View full text Add to dashboard Cite

Isomeric tri‐aryl ketone amines, 1,3‐bis(3‐aminobenzoyl)benzene (133 BABB), 1,3‐bis(4‐aminobenzoyl)benzene (134 BABB), and 1,4‐bis(4‐aminobenzoyl)benzene (144 BABB) are synthesized and cured with diglycidyl ether of bisphenol A and diglycidyl ether of bisphenol F in this work. Differential scanning calorimetry and near‐infrared spectroscopy reveal higher rate constants and enhanced secondary amine conversion with increasing para substitution attributed to resonance effects and the electron withdrawing nature of the carbonyl linkages. Glass transition temperatures increase from 133 BABB to 134 BABB, but decrease modestly for the 144 BABB hardener. With increasing para substitution, the flexural modulus and strength both decrease while the strain to failure increases but all BABB amines displaying higher mechanical properties than the corresponding 4,4‐diaminodiphenyl sulfone (44 DDS) networks. The thermal stability of the BABB networks is found to be modestly lower than 44 DDS, but char yields are significantly higher. Changes in thermal and mechanical properties are described in terms of molecular structure and equilibrium packing density.

show abstract

Simultaneous reinforcement and toughness improvement in an aromatic epoxy network with an aliphatic hyperbranched epoxy modifier

Cited by 55 publications

References 42 publications

An investigation of the relationship between the performance of polybenzoxazine and backbone structure of hyperbranched epoxy modifiers

An investigation of the relationship between the performance of polybenzoxazine and backbone structure of hyperbranched epoxy modifiers

A novel nitrogen, phosphorus, and boron ionic pair compound toward fire safety and mechanical enhancement effect for epoxy resin

Synthesis of tri‐aryl ketone amine isomers and their cure with epoxy resins

Contact Info

Product

Resources

About