scholarly journals Curing Behavior and Thermomechanical Performance of Bioepoxy Resin Synthesized from Vanillyl Alcohol: Effects of the Curing Agent

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2891
Author(s):  
Zhenyu Wang ◽  
Pitchaimari Gnanasekar ◽  
Sandeep Sudhakaran Nair ◽  
Songlin Yi ◽  
Ning Yan
Keyword(s):  
Decomposition Temperature ◽  
Thermomechanical Properties ◽  
Molecular Structures ◽  
Curing Temperature ◽  
Vanillyl Alcohol ◽  
Curing Agent ◽  
Characterization Methods ◽  
Curing Reaction ◽  
Relaxation Temperature ◽  
Petroleum Resources

In order to reduce the dependency of resin synthesis on petroleum resources, vanillyl alcohol which is a renewable material that can be produced from lignin has been used to synthesize bioepoxy resin. Although it has been widely reported that the curing reaction and properties of the cured epoxies can be greatly affected by the molecular structure of the curing agents, the exact influence remains unknown for bioepoxies. In this study, four aliphatic amines with different molecular structures and amine functionalities, namely triethylenetetramine (TETA), Tris(2-aminoethyl)amine (TREN), diethylenetriamine (DETA), and ethylenediamine (EDA), were used to cure the synthesized vanillyl alcohol–based bioepoxy resin (VE). The curing reaction of VE and the physicochemical properties, especially the thermomechanical performance of the cured bioepoxies with different amine functionalities, were systematically investigated and compared using different characterization methods, such as DSC, ATR–FTIR, TGA, DMA, and tensile testing, etc. Despite a higher curing temperature needed in the VE–TETA resin system, the cured VE–TETA epoxy showed a better chemical resistance, particularly acidic resistance, as well as a lower swelling ratio than the others. The higher thermal decomposition temperature, storage modulus, and relaxation temperature of VE–TETA epoxy indicated its superior thermal stability and thermomechanical properties. Moreover, the tensile strength of VE cured by TETA was 1.4~2.6 times higher than those of other curing systems. In conclusion, TETA was shown to be the optimum epoxy curing agent for vanillyl alcohol–based bioepoxy resin.

Study on the Curing Characteristics of MUF Co-Polymerization Resin

2011 ◽  
Vol 183-185 ◽  
pp. 2124-2128
Author(s):  
Yun Wu Zheng ◽  
Li Bin Zhu ◽  
Ji You Gu ◽  
Zhi Feng Zheng ◽  
Yuan Bo Huang
Keyword(s):  
Activation Energy ◽  
Reaction Rate ◽  
Reaction Order ◽  
Curing Temperature ◽  
Curing Agent ◽  
Curing Time ◽  
Curing Reaction ◽  
Curing Characteristics ◽  
Production Practice ◽  
Run Up

Curing is the key to the bonding, this paper considered the production practice, studied the curing properties of different MUF resin under the different curing agent with DSC. The experimental results show that: The characteristics temperature of curing reaction is closely related to the β. With the increase of β, the initial and peak temperature is moving to the high-temperature, the curing time became shorter; the range of curing temperature became much wider. At the same time, the curing peaking temperature was decreased and the Enthalpy integral of curing reaction was reduced first then increased with the increased of the amount of curing agent. When the amount of curing agent occupied 4.0%-6.0% of the MUF resin, the pH was decreased mostly, and the curing reaction rate run up quickly Along with the increasing of n (F): n (U1), the To, Tp and Ti are going ahead distinctly after hardening. At the same time, both activation energy and reaction order are all decreased, absorbed heat is dropping too. So, curing technics became easily.

Research on the Curing Behaviour of an Epoxy/nmSiO2 Nanocomposite System

2009 ◽  
Vol 87-88 ◽  
pp. 293-299
Author(s):  
Chuan Sheng Wang ◽  
Yong Xiang Fu ◽  
Guang Yi Lin
Keyword(s):  
Reaction Order ◽  
Kinetic Equations ◽  
Curing Temperature ◽  
Curing Agent ◽  
Curing Process ◽  
Scanning Calorimetry ◽  
Curing Reaction ◽  
Gelling Temperature ◽  
Nanocomposite System ◽  
Energy Reaction

The curing behaviour of an epoxy/nmSiO2 nanocomposites system composed of a bifunctional epoxy resin with an anhydride curing agent and nmSiO2 was investigated. Differential scanning calorimetry (DSC) was used to investigate the curing behaviour of the nanocomposites system. As for the nanocomposites system containing different amount of nmSiO2, the values of activation energy, reaction order, theoretic gelling temperature and theoretic curing temperature were evaluated by kinetic equations. And the effect of nmSiO2 on the curing reaction and the curing reaction mechanism of the system were discussed. The results showed that the curing rate of the nanocomposites system increased slightly with adaptively increasing nmSiO2 content, and the curing process is at 110°C for 1hr, 150°C for 2hr.

scholarly journals Synthesis and thermal properties of some phenolic resins

2019 ◽  
Vol 7 (1) ◽  
pp. 1-15
Author(s):  
Alshawi F M ◽  
Abdul Razzq K ◽  
Hanoosh W S
Keyword(s):  
Phenol Formaldehyde ◽  
Chemical Properties ◽  
Decomposition Temperature ◽  
Industrial Applications ◽  
Stability Study ◽  
Curing Temperature ◽  
Molar Ratio ◽  
Scanning Calorimetry ◽  
Phenolic Resins ◽  
Physical And Chemical

Introduction: Phenolic resins have been in use since the early twentieth century and are considered the first class of synthetic polymers to achieve commercial success, moreover phenolic resins continue to succeed and attract special interest in a large range of industrial applications such as adhesives, paints, and composites; because of their unique physical and chemical properties. Materials and Methods: Prepolymers resol resins (RR, RH, RP, and RC) were synthesized by the reaction of phenolic compounds (resorcinol, hydroquinone, phloroglucinol, and catechol) respectively, with formaldehyde at molar ratio phenol/ formaldehyde 1/1.5, using sodium hydroxide as a catalyst. These resins were characterized by FTIR. The curing reaction of these resins was evaluated using differential scanning calorimetry (DSC), while the thermal stability study was evaluated using thermogravimetric analysis (TGA). Results and Discussion:From the results showing that these prepolymers have different curing temperatures and curing energy, while the TGA study showed that the cured resins have decomposition temperature more than 300 ºC, and char residue at 650 ºC more than 60%. Conclusions: These resol resins have different gel times (8-55) min, and viscosities (435-350) mpa.s. The curing temperature of these resin obtained from DSC curves was (120, 129, 105 and 127 °C), while the thermal behavior of the cured resins obtained from TGA curves showed that these cured resin have two decomposition temperatures and the rate of decomposition in the order of RC < RR< .

scholarly journals A Study on the Synthesis, Curing Behavior and Flame Retardance of a Novel Flame Retardant Curing Agent for Epoxy Resin

Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 245
Author(s):  
Yong Sun ◽  
Yongli Peng ◽  
Yajiao Zhang
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Decomposition Temperature ◽  
Isothermal Kinetics ◽  
Flame Retardance ◽  
Curing Agent ◽  
Initial Decomposition Temperature ◽  
Limiting Oxygen Index ◽  
Epoxy Resin System ◽  
Dsc Method

In this work, a flame retardant curing agent (DOPO-MAC) composed of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide DOPO and methyl acrylamide (MAC) was synthesized successfully, and the structure of the compound was characterized by FT-IR and 1H-NMR. The non-isothermal kinetics of the epoxy resin/DOPO-MAC system with 1% phosphorus was studied by non-isothermal DSC method. The activation energy of the reaction (Ea), about 46 kJ/mol, was calculated by Kissinger and Ozawa method, indicating that the curing reaction was easy to carry out. The flame retardancy of the epoxy resin system was analyzed by vertical combustion test (UL94) and limiting oxygen index (LOI) test. The results showed that epoxy resin (EP) with 1% phosphorus successfully passed a UL-94 V-0 rating, and the LOI value increased along with the increasing of phosphorus content. It confirmed that DOPO-MAC possessed excellent flame retardance and higher curing reactivity. Moreover, the thermal stability of EP materials was also investigated by TGA. With the DOPO-MAC added, the residual mass of EP materials increased remarkably although the initial decomposition temperature decreased slightly.

Curing Process and Heat-Resistance of Polyethersulfone Toughened Epoxy Resins

2017 ◽  
Vol 898 ◽  
pp. 2302-2308
Author(s):  
Jin Li Zhou ◽  
Shu Zhu ◽  
Wen Pin Jia ◽  
Chao Cheng ◽  
Elwathig A.M. Hassan ◽  
...  
Keyword(s):  
Heat Resistance ◽  
Epoxy Resin ◽  
Thermo Gravimetric Analysis ◽  
Exothermic Peak ◽  
Curing Temperature ◽  
Gravimetric Analysis ◽  
Curing Process ◽  
Thermo Gravimetric ◽  
Rich Phase ◽  
Curing Reaction

In order to improve the toughness of epoxy resin, hydroxyl-terminated polyethersulfone (PES) with various amounts (0 wt.%, 5 wt.%, 10 wt.%, 15 wt.%, 20 wt.%) were added to bisphenol A epoxy resin (DER331)/ curing agent DETDA (E100) systems, and the influence of PES contents on curing process and heat-resistance was studied. Non-isothermal DSC was used to determine the curing process of uncured DER331/E100/PES systems at heating rate of 2°C/min, 5°C/min, 7°C/min, 10°C/min and 15°C/min separately, and the apparent activation energy was calculated based on Kissinger method. The morphology of the etched cured DER331/E100/PES systems with different PES contents was observed by SEM. The heat-resistance of these systems was investigated by DSC and TGA. The results showed that with the increasing of PES content the curing exothermic peak, the heat of curing reaction, the initial and final curing temperature all decreased at the first and then increased, indicating that when the PES content was low (5 wt.%, 10 wt.%), PES can facilitate the curing process, while, when PES content up to 15 wt.%, PES can prevent or weaken the curing reaction. SEM results indicated that the phase structure changed drastically depending on the PES content. The systems with 5 wt.% and 10 wt.% PES were epoxy-rich phase, with 15 wt.% PES was co-continuity phase, and with 20 wt.% PES showed complete phase inversion (PES rich phase). The glass transition temperature and thermo gravimetric analysis demonstrated that the addition of PES can increase the heat resistance of cured DER331/E100/PES systems.

Curing study and evaluation of epoxy resin with amine functional chloroaniline acetaldehyde condensate

2015 ◽  
Vol 44 (1) ◽  
pp. 19-25
Author(s):  
T. Maity ◽  
B.C. Samanta
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Epoxy Resin ◽  
Ph Value ◽  
Kinetic Studies ◽  
Diglycidyl Ether ◽  
Curing Agent ◽  
Scanning Calorimetry ◽  
Content Type ◽  
Curing Reaction

Purpose – The purpose of this paper was to check effectiveness of amine functional chloroaniline acetaldehyde condensate (AFCAC) as a new curing agent for diglycidyl ether of bisphenol A (DGEBA) resin. For this purpose, first AFCAC was synthesised, characterised and then curing reaction was carried out. Design/methodology/approach – Equimolecular mixture of AFCAC and DGEBA was subjected to curing reaction, and the reaction was followed by differential scanning calorimetry (DSC) analysis. The kinetic studies of this curing reaction were also carried out from those DSC exotherms. The mechanical properties, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) of cured epoxy were also reported. Findings – DSC results reflected the effective first order curing reaction of AFCAC with epoxy resin. Mechanical properties reflected appreciable rigidity of AFCAC cured epoxy matrix and TGA showed that the cured epoxy networks were thermally stable up to around 297°C. Research limitations/implications – The curing agent AFCAC was synthesised by using chloroaniline and acetaldehyde in acid medium. There are some limitations for this procedure. The synthetic procedure is pH dependent. So reaction cannot be done at any pH value. The reaction must also be carried out at room temperature without any heating. To obtain low molecular weight curing agent, chloroaniline and acetaldehyde cannot be taken in equimolecular ratio because the equimolecular mixture of them produces high molecular weight condensate. This was shown in our previous publication. Some implications are also there. By changing amine and aldehyde other curing agents could be synthesised and the curing efficiency of those for epoxy resin could also be studied. Originality/value – Experimental results revealed the greater suitability of AFCAC as curing agent for DGEBA resin and novelty of AFCAC cured matrix in the field of protective coating, casting, adhesives, etc.

scholarly journals Structure, stability, and properties of phenolic fibers modified by phenyl molybdate

2020 ◽  
pp. 096739112092780
Author(s):  
Yang Kai ◽  
Jiao Mingli ◽  
Zhang Xiaomei ◽  
Jia Wanshun ◽  
Diao Quan ◽  
...  
Keyword(s):  
Melt Spinning ◽  
Main Chain ◽  
Phenol Formaldehyde ◽  
Gel Permeation Chromatography ◽  
Decomposition Temperature ◽  
Nitrogen Atmosphere ◽  
Molecular Structures ◽  
Structure Stability ◽  
Initial Decomposition Temperature ◽  
Heat Curing

Phenyl molybdate-modified phenolic fibers (PMoPFs) were prepared by melt spinning from the corresponding resin which was polymerized from phenol, formaldehyde, and phenyl molybdate, followed by solution curing and then heat curing processes. The molecular structures, including characteristic groups and molecular weight, were examined by nuclear magnetic resonance, Fourier transform infrared spectroscopy, and gel permeation chromatography. The influences of the curing processes were demonstrated by mechanical properties, scanning electron microscopy, and thermogravimetric analysis characterization. PMoPF with 8 wt% molybdic acid and cured in an oven possessed a tensile strength as high as 187 MPa, initial decomposition temperature of 300°C, and a char yield under nitrogen atmosphere at 800°C as high as 66.0%, with the molybdate (MoO4 2−) groups being introduced into the phenolic main chain.

Curing Reaction and Kinetic Parameters of Diallyl Orthophthalate Resin with Initiator Dicumyl Peroxide

2010 ◽  
Vol 160-162 ◽  
pp. 1366-1371
Author(s):  
Xiao Qin Yue ◽  
Qi Lin Mei ◽  
Zhi Xiong Huang ◽  
Peng Wen ◽  
Ling Huang
Keyword(s):  
Kinetic Parameters ◽  
Frequency Factor ◽  
Treatment Temperature ◽  
Curing Temperature ◽  
Dicumyl Peroxide ◽  
Scanning Calorimetry ◽  
Thermal Treatment Temperature ◽  
Reaction Heat ◽  
Curing Reaction ◽  
Gel Temperature

The curing reaction of diallyl orthophthalate(DAOP) resin, which was initiated by dicumyl peroxide(DCP), was studied by Fourier transform infrared spectroscopy(FTIR). Differential scanning calorimetry(DSC) was used to determine the curing behavior and kinetic parameters of dicumyl peroxide (DCP) / diallyl orthophthalate (DAOP) system. The results clarified that the curing reaction of DAOP resin could be initiated by DCP at 150-180°C and the reaction heat diffused slowly in curing process. The gel-temperature, curing temperature and thermal treatment temperature of the DCP(3%)/DAOP system were 145.46°C, 166.03°C and 173.83°C. The apparent activation energy, frequency factor and reaction order were 130.200kJ/mol, 5.231×1010 and 0.9455, respectively.

Study on the Preparation of 2-Phenyl Imidazole Microcapsule and its Effect on Curing Epoxy Resin

2013 ◽  
Vol 690-693 ◽  
pp. 1649-1652
Author(s):  
Ai Jie Ma ◽  
Qiu Yu Zhang ◽  
You Qiang Shi
Keyword(s):  
Epoxy Resin ◽  
Raw Materials ◽  
Curing Kinetics ◽  
Curing Temperature ◽  
Curing Agent ◽  
Thermal Analyzer ◽  
Epoxy Resin System ◽  
Curing Kinetic ◽  
Resin Curing ◽  
Micro Morphology

In this paper, 2-phenyl imidazole (2-PZ) microcapsule-type curing agent of epoxy resin were prepared through solvent volatilization with 2-PZ and polymethyl acrylic glycidyl ester (PGMA) as the raw materials. The micro-morphology, shape and structure of the microcapsules were studied by scanning electronic microscope (SEM) and fourier transform infrared spectrum (FT-IR). The curing kinetics of microcapsule curing agent/epoxy resin E-44 curing system were studied using TGA/DSC simultaneous thermal analyzer. Results showed that the preparation method is simple and effective and the prepared 2-PZ microcapsules have smooth surfaces and monodisperse size. And the curing kinetic study of epoxy resin system suggested epoxy resin curing temperature was rising with the increase of heating rate.

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