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.

Curing Kinetics of Phenol Formaldehyde Resin Modified with Sodium Silicate

2012 ◽  
Vol 184-185 ◽  
pp. 1471-1479
Author(s):  
Jin Sun ◽  
Xiao Feng Zhu ◽  
Xiao Bo Wang ◽  
Rui Hang Lin ◽  
Zhen Zhong Gao
Keyword(s):  
Activation Energy ◽  
Sodium Silicate ◽  
Reaction Order ◽  
Phenol Formaldehyde ◽  
Curing Kinetics ◽  
Curing Temperature ◽  
Formaldehyde Resin ◽  
Exponential Factor ◽  
Curing Reaction ◽  
Kinetics Of

The curing kinetics of PF resin modified with sodium silicate had been investigated by differential scanning calorimetry (DSC). The kinetic analysis was performed at heating rates of 5, 10, 15, and 20°C/min，respectively. The kinetic parameters such as reaction order and activation energy were solved by Kissinger and Crane equation. The relationship between curing temperature and heating rate was also investigated. The activation energy and the curing reaction order，which were obtained by kinetic calculation, are 83.00kJ/mol and 0.917, respectively. The curing reaction kinetics equations were built by the obtained best curing temperature, reaction order, pre-exponential factor and reaction rate constant.

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 Study of the kinetics of Bombyx mori chitosan ascorbate formation

2020 ◽  
Vol 99 (3) ◽  
pp. 38-43
Author(s):  
K.K. Pirniyazov ◽  
◽  
S.Sh. Rashidova ◽  
Keyword(s):  
Activation Energy ◽  
Ascorbic Acid ◽  
Bombyx Mori ◽  
Equilibrium Constant ◽  
Reaction Rate ◽  
Reaction Order ◽  
Average Rate ◽  
Kinetic Studies ◽  
Water Soluble ◽  
The One

In this work, for the first time, a water-soluble natural biopolymer of chitosan ascorbate based on Bombyx mori chitosan and ascorbic acid was obtained and kinetic features of the process were determined. Samples of chitosan ascorbate were synthesized, the interaction of chitosan with ascorbic acid was studied by analytical titration. The synthesis was carried out in order to determine the activation energy of formation of the reaction of chitosan ascorbate, in the ratio of chitosan and ascorbic acid (4:1) components for 15 minutes with a reaction temperature ranging from 25°C to 65°C. The results of the kinetic studies show that in the interaction under the study the reaction order on ascorbic acid concentration exceeds the reaction order on chitosan concentration, while the reaction activation energy was determined, which equals to 13.38 kJ/mol. This result allows us to conclude that during the formation of chitosan ascorbate at 55 °C the highest equilibrium constant is established, and a further increase in temperature leads to a decrease in the yield and equilibrium constant. The results obtained indicate that with an increase in the concentration of ascorbic acid compared to the one of chitosan, the reaction rate increased almost twice. It was found that with an increase in the reaction time, the average rate of synthesis gradually decreases. This is due to the fact that with an increase in the duration of the reaction in the solution the concentration of unbound (free) ascorbic acid decreases, and as a result, the reaction rate decreases as well.

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.

Research on the Curing Behaviour and Morphology of an Epoxy/OMMT Nanocomposite System

2011 ◽  
Vol 221 ◽  
pp. 221-227 ◽  
Author(s):  
Guang Yi Lin ◽  
Dian Wei Qu ◽  
Chuan Sheng Wang
Keyword(s):  
Reaction Order ◽  
Kinetic Equations ◽  
Interlayer Spacing ◽  
Curing Temperature ◽  
Curing Process ◽  
Scanning Calorimetry ◽  
Curing Reaction ◽  
Gelling Temperature ◽  
Nanocomposite System ◽  
Energy Reaction

The curing behaviour of an epoxy/OMMT nanocomposites system which was composed of a bifunctional epoxy resin with an anhydride curing agent and OMMT was investigated. Differential scanning calorimetry (DSC) was used to investigate the curing behaviour of the nanocomposites system. As for the nanocomposites system containing different amounts of OMMT, the values of activation energy, reaction order, theoretic gelling temperature and theoretic curing temperature were evaluated by kinetic equations. And the effect of OMMT on the curing reaction and the curing reaction mechanism of the system were discussed. The results showed that the curing process is at 100°C for 1hr, 170°C for 2hr when the OMMT content is 3%. XRD was used to observe the interlayer spacing of the OMMT and SEM was used to survey the morphology of nanocomposites system.

scholarly journals Preparation and characterization of fast-curing powder epoxy adhesive at middle temperature

2018 ◽  
Vol 5 (8) ◽  
pp. 180566 ◽  
Author(s):  
Jie Xu ◽  
Jiayao Yang ◽  
Xiaohuan Liu ◽  
Hengxu Wang ◽  
Jingjie Zhang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Weight Ratio ◽  
Epoxy Adhesive ◽  
Exothermic Peak ◽  
Curing Temperature ◽  
Curing Time ◽  
Scanning Calorimetry ◽  
Cure Reaction ◽  
Exponential Factor ◽  
Blending Method

At present, the disadvantage of powder epoxy adhesive is the limited application area. In order to widen the application range of powder epoxy adhesive from heat-resistant substrates (such as metals) to heat-sensitive substrates (such as plastic products, cardboard and wood), it is necessary to decrease the curing temperature. In this article, a series of fast-curing powder epoxy adhesives were prepared by the melt blending method with bisphenol A epoxy resin (E-20), hexamethylenetetramine (HMTA) as a curing agent and 2-methylimidazole (2-MI) as an accelerant. The structure and properties of the E-20/HMTA/2-MI systems were characterized by Fourier transform infrared, thermogravimetric analysis, dynamic mechanical analyser and differential scanning calorimetry (DSC). 2-MI added into the E-20/HMTA systems can simultaneously enhance toughness, tensile strength, glass transition temperature ( T g ) and thermal stability in comparison with the E-20/HMTA systems. The best mechanical properties were obtained at 100/8/0.6 weight ratio of the E-20/HMTA/2-MI systems. DSC experiments revealed that the exothermic peak of the E-20/HMTA/2-MI system was about 55°C lower than that of the E-20/HMTA system. The activation energy of the cure reaction was determined by both Kissinger's and Ozawa's methods at any heating rates. The activation energy and pre-exponential factor were about 100.3 kJ mol −1 and 3.57 × 10 11 s −1 , respectively. According to the KAS method, the curing time of the E-20/HMTA/2-MI systems was predicted by evaluating the relationship between temperature and curing time.

scholarly journals Differences of Curing Effects between a Human and Veterinary Bone Cement

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 470 ◽  
Author(s):  
K. Kallol ◽  
M. Motalab ◽  
M. Parvej ◽  
P. Konari ◽  
H. Barghouthi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Mechanical Behavior ◽  
Bone Cement ◽  
Curing Temperature ◽  
Interface Fracture ◽  
Curing Time ◽  
Curing Conditions ◽  
Curing Characteristics ◽  
Significant Difference

The goal of the study is to understand how the curing characteristics of a human bone cement (HBC) and veterinary bone cement (VBC) influence the mechanical behavior of each cement and cement bonding with an implant. This study hypothesizes that the curing temperature and time influence the mechanical properties of the cement adjacent to the implant, which resulted in the variability in bonding strength between the implant and cement. To test this hypothesis, this study measured the exothermic temperature, flexural strength, hardness, and morphology of a HBC and VBC at different curing times. In addition, this study measured shear strength at the interfaces of implant/HBC and implant/VBC samples during static and stepwise cyclic tests at different curing times. This study used Stryker Simplex P and BioMedtrix 3 poly methyl methacrylate (PMMA) as an HBC and VBC, respectively. This study cured HBC and VBC cement for 30 and 60 min and then conducted flexural, hardness, and interface fracture tests to evaluate the curing effect on mechanical behavior of each of the cements. This study found that the curing time significantly increases the values of flexure and hardness properties of each cement and shear strength of implant/HBC and implant/VBC (p < 0.05). This study observed a difference of curing time and temperature between HBC and VBC. This study also observed a significant difference of surface porosity at the interface of implant/HBC and implant/VBC interfaces. The variability of mechanical properties between HBC and VBC due to the differences of curing conditions may influence the bonding of cement with the implant.

Study on Curing Characteristics of Low-Toxicity Urea-Formaldehyde Resin

2011 ◽  
Vol 393-395 ◽  
pp. 1447-1450
Author(s):  
Shu Min Wang ◽  
Jun You Shi
Keyword(s):  
Activation Energy ◽  
Urea Formaldehyde ◽  
Formaldehyde Resin ◽  
Test Results ◽  
Hot Press ◽  
Curing Reaction ◽  
Uf Resin ◽  
Curing Characteristics ◽  
Low Toxicity ◽  
Hot Press Process

Curing characteristics of low-toxicity urea-formaldehyde (UF) resin in different curing system were studied by differential scanning carlorimetry (DSC). Test results showed that the initial orterminal temperature and activation energy needed of curing reaction for low-toxicity UF resin were different in different curing system. The initial temperature of curing reaction for low-toxicity UF resin and activation energy were the lowest, and exotherm was most under curing system C, which showed the acceleration of curing system C on low-toxicity UF resin was best. The appropriate curing system can be optimized and applied for hot-press process in practical production by means of DSC to investigate curing characteristics of low-toxicity UF resin.

Effect of Curing Temperature and Cross-Linker to Pre-Polymer Ratio on the Viscoelastic Properties of a PDMS Elastomer

2015 ◽  
Vol 1112 ◽  
pp. 410-413 ◽  
Author(s):  
Firdaus Prabowo ◽  
Adrian Law Wing-Keung ◽  
Hayley H. Shen
Keyword(s):  
Curing Temperature ◽  
Curing Agent ◽  
Curing Time ◽  
Small Amplitude Oscillatory Shear ◽  
Pdms Elastomer ◽  
Linear Viscoelastic ◽  
Cross Linker ◽  
G Value ◽  
The Stability ◽  
Polymer Ratio

Viscoelastic samples made from a PDMS elastomer, Sylgard 184 (Dow Corning, USA), were prepared using 9.1% and 3% curing agent (cross-linker) and heat-cured with four curing temperatures from 25° to 150°C and four curing durations from 48 h to 25 min. Small amplitude oscillatory shear (SAOS) rheometry was done to examine their mechanical properties, represented by the storage (G’) and loss (G”) moduli. Generally, G’ and G” are dependent on the frequency, curing agent percentage and curing temperature. The samples were then reheated and SAOS tested again to check the stability of G’ and G”. It was apparent that the stability of G’ and G” are both strongly dependent on the curing temperature. Samples with the curing temperature of 25°C yielded almost up to 4 times change of G” value for 9.1% curing agent and more than 2 times change of G’ value for 3% curing agent. Hence, the usage of 25°C curing temperature at the manufacturer recommended curing time is not suitable for applications where the linear viscoelastic stability is important. In general, the stability also improves as the frequency increases for all samples.

Study on Curing Reaction and Mechanical Properties of Liquid Crystalline P-SBPEPB/BPAER/MeTHPA System

2011 ◽  
Vol 109 ◽  
pp. 170-173
Author(s):  
Li Huo ◽  
Yong Gang Du ◽  
Yong Mei Wang
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Mechanical Property ◽  
Differential Scanning Calorimetry ◽  
Liquid Crystalline ◽  
Cure Kinetics ◽  
Curing Agent ◽  
Scanning Calorimetry ◽  
Curing Reaction ◽  
Dsc Method

The cure kinetics for bisphenol A epoxy resin (BPAER) modified by liquid crystalline Sulfonyl bis(4,1-phenylene)bis[4-(2,3-epoxypropyloxy)benzoate](p-SBPEPB), with3-methyl-tetrahy drophthalic anhydride (MeTHPA) as a curing agent, were investigated by nonisothermal differential scanning calorimetry (DSC) method. The effect of the different liquid crystalline contents and activation energy (Ea) on curing reaction were discussed. The glass transition temperature (Tg) and mechanical property were charactered, The results show that the better content is about 10wt%.

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