scholarly journals Synthesis, Thermal Properties and Curing Kinetics of Hyperbranched BPA/PEG Epoxy Resin

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.

2015 ◽  
Vol 618 ◽  
pp. 18-25 ◽  
Author(s):  
Xiangyun Zheng ◽  
Daoke Li ◽  
Chuanyi Feng ◽  
Xiaoting Chen

2011 ◽  
Vol 239-242 ◽  
pp. 1022-1025
Author(s):  
Jun Gang Gao ◽  
Xue Fang Zhang ◽  
Hong Qiu Lv

In order to improve the properties of boron-containing phenol-formaldehyde resin (BPFR), the tetrabromo-bisphenol A epoxy resin (TBBPAER) was used to cure BPFR. The curing mechanism, thermal properties and the fire resistance of TBBPAER/BPFR were investigated by fourier transform infrared spectrometer (FTIR), thermal gravimetric analysis (TGA), torsional braid analysis (TBA) and the oxygen index method. The results show, -OH of -C6H4-CH2OH and -C6H4OH reacts with the epoxy group. With the increase in the amount of BPFR, the thermal properties get better. When the additive amount of TBBPAER is 10 wt%, this material has best thermal stability at high temperature and higher temperature of loss bromine. The glass transition temperature (Tg) is 223.2 °C and the LOI is 68.5.


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

2019 ◽  
Vol 25 (4) ◽  
pp. 478-484
Author(s):  
Haoqing XU ◽  
Yuan FANG ◽  
Aizhao ZHOU ◽  
Pengming JIANG ◽  
Shi SHU ◽  
...  

Epoxy resin insulation paint was prepared with epoxy resin (E44) as binder and with proper inorganic fillers and curing agent (T31) as additives. The isothermal curing reaction process of paint was studied by the differential scanning calorimetry method (DSC), and the curves of curing reaction rate versus time of paint were obtained. The curing reaction kinetics was investigated by using the phenomenological method, and the corresponding parameters of the n-order model, autocatalytic model and Kamal model were determined by fitting the experimental data, respectively. According to the values of R2 and the sum of square due to error (SSE), a suitable curing reaction kinetic model was determined. The curing reaction mechanism of paint was ascertained by the dynamic temperature DSC method and IR spectroscopy (FTIR) method. The results show that the Kamal model can be used to describe the curing kinetics of epoxy resin paint, and the total reaction orders increase from 1.30 to 2.14. The two rate constants increase with the increase of the curing temperature. The activation energy is 90.5832 kJ/mol and 68.3733 kJ/mol respectively, and the pre-exponential factors are 6.521 × 1015 s-1 and 6.3807 × 109 s-1. The curing reaction of paint consists of two steps: the first step is the addition reaction of epoxy group and primary amine or secondary amine; the second step is the etherification reaction of epoxy group and phenolic hydroxyl or alcoholic hydroxyl. Epoxy resin insulation paint was prepared with epoxy resin (E44) as binders and with proper inorganic fillers and curing agent (T31) as additives. The isothermal curing reaction process of paint was studied by differential scanning calorimetry method (DSC), and the curves of curing reaction rate versus time of paint were obtained. The curing reaction kinetics was studied by using the phenomenological method, the corresponding parameters of the n-order model, autocatalytic model and Kamal model were determined by fitting the experimental data, respectively. According to the values of R2 and the sum of square due to error (SSE), a suitable curing reaction kinetic model was determind. The curing reaction mechanism of paint was ascertained by dynamic temperature DSC method and IR spectrogram (FTIR) method. The results show that the kamal model can be used to describe the curing kinetics of epoxy resin paint, the total reaction orders increase from 1.30 to 2.14. The results also show that the two rate constants increase with increasing curing temperature, The activation energies are 90.5832 kJ/mol and 68.3733 kJ/mol, and the pre-exponential factor are 6.521×1015 s-1 and 6.3807×109 s-1. The curing reaction of paint in two steps, the first step is the addition reaction of epoxy group and primary amine or secondary amine. The second step is the etherification reaction of epoxy group and phenolic hydroxyl or alcoholic hydroxyl.


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

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