Crystal structure, curing kinetics, and thermal properties of bisphenol fluorene epoxy resin

2010 ◽  
pp. n/a-n/a ◽  
Author(s):  
Yuanqin Xiong ◽  
Hanping Liu ◽  
Encai Ou ◽  
Xiaoliang Zeng ◽  
Wei Zhou ◽  
...  
2015 ◽  
Vol 618 ◽  
pp. 18-25 ◽  
Author(s):  
Xiangyun Zheng ◽  
Daoke Li ◽  
Chuanyi Feng ◽  
Xiaoting Chen

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1545 ◽  
Author(s):  
Tossapol Boonlert-uthai ◽  
Chavakorn Samthong ◽  
Anongnat Somwangthanaroj

The hyperbranched epoxy resins (HBE) composed of bisphenol A (BPA) and polyethylene glycol (PEG) as reactants and pentaerythritol as branching point were successfully synthesized via A2 + B4 polycondensation reaction at various BPA/PEG ratios. The 13C NMR spectra revealed that the synthesized HBE mainly had a dendritic structure as confirmed by the high degree of branching (DB). The addition of PEG in the resin enhanced degree of branching (DB) (from 0.82 to 0.90), epoxy equivalent weight (EEW) (from 697 g eq−1 to 468 g eq−1) as well as curing reaction. Adding 5–10 wt.% PEG in the resin decreased the onset and peak curing temperatures and glass transition temperature; however, adding 15 wt.% PEG in the resin have increased these thermal properties due to the lowest EEW. The curing kinetics were evaluated by fitting the experimental data of the curing behavior of all resins with the Šesták–Berggren equation. The activation energy increased with the increase of PEG in the resins due to HBE’s steric hindrance, whereas the activation energy of HBE15P decreased due to a large amount of equivalent active epoxy group per mass sample. The curing behavior and thermal properties of obtained hyperbranched BPA/PEG epoxy resin would be suitable for using in electronics application.


2007 ◽  
Vol 106 (3) ◽  
pp. 1476-1481 ◽  
Author(s):  
Zhen Dai ◽  
Yanfang Li ◽  
Shuguang Yang ◽  
Chengzhong Zong ◽  
Xukui Lu ◽  
...  

2019 ◽  
Vol 680 ◽  
pp. 178348 ◽  
Author(s):  
Lisheng Zhou ◽  
Guangcheng Zhang ◽  
Shishan Yang ◽  
Libo Yang ◽  
Jiping Cao ◽  
...  

2017 ◽  
Vol 58 (7) ◽  
pp. 1492-1495
Author(s):  
S. A. Cherkasov ◽  
◽  
E. S. Vikulova ◽  
N. S. Nikolaeva ◽  
A. I. Smolentsev ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2429
Author(s):  
Krittameth Kiatiporntipthak ◽  
Nanthicha Thajai ◽  
Thidarat Kanthiya ◽  
Pornchai Rachtanapun ◽  
Noppol Leksawasdi ◽  
...  

Polylactic acid (PLA) was melt-blended with epoxy resin to study the effects of the reaction on the mechanical and thermal properties of the PLA. The addition of 0.5% (wt/wt) epoxy to PLA increased the maximum tensile strength of PLA (57.5 MPa) to 67 MPa, whereas the 20% epoxy improved the elongation at break to 12%, due to crosslinking caused by the epoxy reaction. The morphology of the PLA/epoxy blends showed epoxy nanoparticle dispersion in the PLA matrix that presented a smooth fracture surface with a high epoxy content. The glass transition temperature of PLA decreased with an increasing epoxy content owing to the partial miscibility between PLA and the epoxy resin. The Vicat softening temperature of the PLA was 59 °C and increased to 64.6 °C for 0.5% epoxy. NMR confirmed the reaction between the -COOH groups of PLA and the epoxy groups of the epoxy resin. This reaction, and partial miscibility of the PLA/epoxy blend, improved the interfacial crosslinking, morphology, thermal properties, and mechanical properties of the blends.


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