The Effect of POSS-NH2 on the Curing Reaction of Cyanate Ester Resin

2011 ◽  
Vol 217-218 ◽  
pp. 274-279 ◽  
Author(s):  
Zeng Ping Zhang ◽  
Jian Zhong Pei ◽  
Shuan Fa Chen ◽  
Hong Zhao Du ◽  
Yong Wen
Keyword(s):  
Reaction Mechanisms ◽  
Catalytic Effect ◽  
Curing Kinetics ◽  
Cyanate Ester ◽  
Cyanate Ester Resin ◽  
Curing Reaction ◽  
Ft Ir ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Different Content

A functional POSS monomer (POSS-NH2) was employed to modify cyanate ester (CE) resin. A series of POSS-NH2/CE hybrids containing different content of POSS have been prepared by melt casting and then curing. The curing kinetics and reaction mechanisms of the resin systems were studied by using FT-IR. The experimental results show that both temperature and POSS content may influence the curing reaction of CE. POSS-NH2 mainly displays the catalytic effect at higher temperature (220oC). While the circumstance is more complex at lower temperature (190oC).

POSS-NH2/Cyanate Ester Resin Organic-Inorganic Hybrids: Curing Reaction and Dielectric Properties

2011 ◽  
Vol 266 ◽  
pp. 147-150 ◽  
Author(s):  
Zeng Ping Zhang ◽  
Shuan Fa Chen ◽  
Jian Zhong Pei
Keyword(s):  
Dielectric Properties ◽  
Catalytic Effect ◽  
Curing Kinetics ◽  
Cyanate Ester ◽  
Cyanate Ester Resin ◽  
Curing Reaction ◽  
Ft Ir ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Different Content

A functional POSS monomer (POSS-NH2) was employed to modify cyanate ester (CE) resin. A series of POSS-NH2/CE hybrids containing different content of POSS have been prepared by melt casting and then curing. The curing kinetics and reaction mechanisms of the resin systems were studied by using FT-IR. Dielectric properties of the hybrids were also investigated. FT-IR results show that both temperature and POSS content may influence the curing reaction of CE. POSS-NH2 mainly displays the catalytic effect at higher temperature (220oC). The circumstance is more complex at lower temperature(190oC). CE1 containing 1 wt% of POSS has the best dielectric properties.

Preparation and Dielectric Properties of POSS-NH2/Cyanate Ester Resin Organic-Inorganic Hybrids

2011 ◽  
Vol 216 ◽  
pp. 635-639 ◽  
Author(s):  
Zeng Ping Zhang ◽  
Jian Zhong Pei ◽  
Shuan Fa Chen ◽  
Hong Zhao Du ◽  
Yong Wen
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Cyanate Ester ◽  
Cyanate Ester Resin ◽  
Curing Reaction ◽  
Ft Ir ◽  
Different Content

In order to improve the dielectric and overal properties of cyanate ester (CE) resin, a functional POSS monomer(octa(aminopropyl)silsesquioxane, POSS-NH2), was employed to modify CE. A series of POSS-NH2/CE hybrids (CE, CE1, CE2, CE3 and CE4) containing different content of POSS have been prepared by melt casting and then curing. The curing reaction of the resin systems were monitored by FT-IR. Dielectric properties of the hybrids were investigated in detail. FT-IR results showed the almost disappearance of the –OCN for all resin systems, suggesting the complete curing of CE using the experimental curing technique. Dielectric investigation indicates that CE1 which contains 1 wt% of POSS has the best dielectric properties with not only lowest dielectric constant but also lowest dielectric loss.

scholarly journals Synthesis of Fe3O4 and Fe2O3 nanoparticles using hybrid electrochemical-thermal method

2020 ◽  
Vol 55 (3) ◽  
pp. 221-228
Author(s):  
HA Simol ◽  
R Sultana ◽  
M Y A Mollah ◽  
MS Miran
Keyword(s):  
Iron Oxide ◽  
Total Pore Volume ◽  
Thermal Method ◽  
Prepared Compound ◽  
Xrd Pattern ◽  
Spectral Techniques ◽  
Different Temperatures ◽  
Ft Ir ◽  
Higher Temperature ◽  
Lower Temperature

Nanocrystalline Fe3O4 and Fe2O3 particles were successfully synthesized by an innovative hybrid electrochemical-thermal method. The as-prepared compound was calcined for an hour from 100 to 600oC temperatures. The crystallinity, morphology and chemical state of the synthesized powders were characterized by XRD, TG-DTA, SEM/EDS, FT-IR, and UV–Vis spectral techniques after calcinations. The Brunauer–Emmett–Teller (BET) plots confirmed that iron oxide nanoparticles (NPs) calcined at 400oC has a surface area of 18.28 m2 g-1 with a total pore volume of 0.2064 cc g-1. From XRD pattern it is revealed that the precursor calcined at lower temperature (100-400oC) correspond to Fe3O4,while the ones calcined at higher temperature follow Fe2O3 pattern. The morphology of iron oxide NPs calcined at different temperatures were studied with scanning electron microscope (SEM) and exhibits spherical shaped geometries with average diameters of 80-150nm. Bangladesh J. Sci. Ind. Res.55(3), 221-228, 2020

Preparation of hybrid cyanate ester resin in the presence of polysilazane and its properties

2020 ◽  
pp. 095400832095161
Author(s):  
Xiaomeng Huo ◽  
Kangkang Guo ◽  
Fan Wang ◽  
Yaping Zhu ◽  
Huimin Qi
Keyword(s):  
Ir Spectroscopy ◽  
Flexural Modulus ◽  
Cyanate Ester ◽  
Curing Temperature ◽  
Polymerization Reaction ◽  
Polymerization Temperature ◽  
Cyanate Ester Resin ◽  
Short Period ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

A hybrid cyanate ester resin containing polysilazane was prepared via the prepolymerization of bisphenol-A dicyanate ester monomer (BADCy) in the presence of polysilazane (PSZ) under low temperature conditions in a short period of time. Fourier transform-infrared (FT-IR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy reveal that the polymerization reaction of BADCy can be carried out in the presence of PSZ to obtain a hybrid resin below 100°C and polymethylsilazane (PHS) exhibits an improved prepolymerization effect when compared to polydimethylsilazane (PMS). FT-IR spectroscopy and gel permeation chromatography (GPC) showed that the prepolymerization degree of the PHS/BADCy resin increased upon increasing PHS mass fraction from 0 to 12 wt%, polymerization temperature from 60 to 100°C and polymerization time from 0 to 4 h. The PHS/BADCy hybrid resins samples were prepared and their process properties were investigated by rheometry and Differential scanning calorimetry (DSC). The results indicated that their viscosity was <10 Pa.s in the temperature range of 60–130°C, and the initial curing temperature and curing exothermic enthalpy were 121.9°C and 358.9 J/g, respectively. Furthermore, the cured PHS/BADCy resin possesses excellent thermal and mechanical properties, the 5% weight loss temperature (Td5) and glass transition temperature (Tg) were 424–441°C and 273–282°C, respectively. The cured PHS/BADCy resin with 4 wt% PHS showed the highest flexural strength of 146 MPa and flexural modulus of 4.1 GPa.

scholarly journals Reconstruction of the Microstructure of Cyanate Ester Resin by Using Prepared Cyanate Ester Resin Nanoparticles and Analysis of the Curing Kinetics Using the Avrami Equation of Phase Change

2019 ◽  
Vol 9 (11) ◽  
pp. 2365
Author(s):  
Hongtao Cao ◽  
Beijun Liu ◽  
Yiwen Ye ◽  
Yunfang Liu ◽  
Peng Li
Keyword(s):  
Phase Change ◽  
Curing Kinetics ◽  
Cyanate Ester ◽  
Avrami Equation ◽  
Resin Matrix ◽  
Curing Process ◽  
Microscopic Mechanism ◽  
Mechanism Model ◽  
Cyanate Ester Resin ◽  
Gel Particles

Bisphenol A dicyanate (BADCy) resin nanoparticles were synthesized by precipitation polymerization and used to modulate the microstructure of the BADCy resin matrix. A microscopic mechanism model was used to characterize the curing process of BADCy resin systems with different contents of the prepared nanoparticles. Due to the curing process of the thermosetting resin being analogous to the crystallization process of the polymer, the Avrami equation was used to analyze the microscopic mechanism of the curing process. The reactive functional groups, structure, and size of the prepared BADCy resin nanoparticles were characterized by FT-IR, SEM, and TEM, respectively. The kinetic parameters of different systems were then obtained using the Avrami equation, and they adequately explained the microscopic mechanism of the curing process. The results showed that the Avrami equation effectively described the formation and growth of gel particles during the curing process of the BADCy resins. The addition of nanoparticles can affect the curing behavior and curing rate. Since the reaction between the BADCy resin nanoparticles and the matrix is dominant, the formation process of the gel particles was neglected. This phenomenon can be understood as the added BADCy resin nanoparticles replacing the formation of gel particles. The reasons for accelerated curing were analyzed from the perspective of thermodynamics and kinetics. Besides this, the Arrhenius equation for non-isothermal conditions correctly accounted for the change in the cross-linked mechanism in the late-stage curing process. A comparison of the theoretical prediction with the experimental data shows that the Avrami theory of phase change can simulate the curing kinetics of different BADCy resin systems well and explain the effects of BADCy resin nanoparticles on the formation of the microstructure.

Molecular Weight and its Distribution of PET Depolymerization Catalyzed by Zn(Ac)2 under Microwave Irradiation

2013 ◽  
Vol 683 ◽  
pp. 254-257 ◽  
Author(s):  
Ke Wen Shu ◽  
Qing Hua Tang ◽  
Huan Wang ◽  
Na Liu ◽  
Dong Zhang
Keyword(s):  
Molecular Weight ◽  
Microwave Irradiation ◽  
Catalytic Effect ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Better Than

In this paper, the molecular weight and its distribution of PET during the process of the PET depolymerization catalyzed by Zn(Ac)2 under microwave irradiation were determined and studied via the method of GPC in 180°C, 190°C and 200°C respectively. The morphologies of the undepolymerized PET observed by SEM was used for the comparation of using or no catalyst. The results shown that Zn(Ac)2 could accelerate the depolymerization rate significantly, and the catalytic effect in lower temperature was better than that in higher temperature.

Curing Behavior and Thermal Properties of Me-SSQ/Cyanate Ester Resin Organic-Inorganic Hybrids

2011 ◽  
Vol 228-229 ◽  
pp. 83-87
Author(s):  
Zeng Ping Zhang ◽  
Shuan Fa Chen ◽  
Jian Zhong Pei
Keyword(s):  
Thermal Properties ◽  
Fourier Transforms ◽  
Cyanate Ester ◽  
Curing Behavior ◽  
Cyanate Ester Resin ◽  
Hydrolysis And Condensation ◽  
Ft Ir ◽  
Thermal Properties Of Materials ◽  
Properties Of Materials ◽  
Ft Ir Spectroscopy

A kind of nonfunctional silsesquioxane (SSQ), methylsilsesquioxane (Me-SSQ), was used to modify cyanate ester resin (CE) in this paper. First, methylsilsesquioxane (Me-SSQ) was synthesized by the hydrolysis and condensation of methyltriethoxysilane. Then a series of Me-SSQ/CE hybrids containing 0wt%, 1wt%, 5wt%, 10wt% and 20wt% of Me-SSQ were prepared. The effect of Me-SSQ content on the curing behavior and thermal properties of materials was investigated by using Fourier transforms infrared (FT-IR) spectroscopy and thermogravimetry (TG), respectively. FT-IR results indicate that the addition of Me-SSQ does not show significant effect on the conversion of CE. However, TG data show that Me-SSQ improved the thermal properties of CE greatly.

Modification of Cyanate Ester Resin by Epoxy-Functionalized Polyhedral Oligomeric Silsesquioxane

2012 ◽  
Vol 549 ◽  
pp. 314-317 ◽  
Author(s):  
Zeng Ping Zhang ◽  
Jian Zhong Pei ◽  
Chang Qing Fang ◽  
Shuan Fa Chen
Keyword(s):  
Impact Strength ◽  
Flexural Strength ◽  
Polyhedral Oligomeric Silsesquioxane ◽  
Cyanate Ester ◽  
Cyanate Ester Resin ◽  
Oligomeric Silsesquioxane ◽  
Different Content

A series of cyanate ester resin (CE) based organic-inorganic hybrids containing different content (0, 5, 10, 15 and 20 wt%) of epoxy functionalized polyhedral oligomeric silsesquioxane (POSS-Ep) were prepared by casting and curing. Impact and flexural strengths of the hybrids were investigated. Results showed that CE10 containing 10wt% of POSS-Ep displayed not only the optimum impact strength but the optimum flexural strength.

scholarly journals Physical and chemical characterizations of biochars derived from different agricultural residues

2014 ◽  
Vol 11 (8) ◽  
pp. 11727-11746 ◽  
Author(s):  
K. Jindo ◽  
H. Mizumoto ◽  
Y. Sawada ◽  
M. A. Sanchez-Monedero ◽  
T. Sonoki
Keyword(s):  
Carbon Fixation ◽  
Chemical Compositions ◽  
Soil Microbial ◽  
Surface Areas ◽  
Oak Tree ◽  
Ft Ir ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Increasing Temperature ◽  
Physical And Chemical

Abstract. Biochar has received large attention as a strategy to tackle against carbon emission. Not only carbon fixation has been carried out but also other merits for agricultural application due to unique physical and chemical character such as absorption of contaminated compounds in soil, trapping ammonia and methane emission from compost, and enhancement of fertilizer quality. In our study, different local waste feed stocks (rice husk, rice straw, wood chips of apple tree (Malus Pumila) and oak tree (Quercus serrata)), in Aomori, Japan, were utilized for creating biochar with different temperature (400–800 °C). Concerning to the biochar production, the pyrolysis of lower temperature had more biochar yield than higher temperature pyrolysis process. On the contrary, surface areas and adsorption characters have been increased as increasing temperature. The proportions of carbon content in the biochars also increased together with increased temperatures. Infrared-Fourier spectra (FT-IR) and 13C-NMR were used to understand carbon chemical compositions in our biochars, and it was observed that the numbers of the shoulders representing aromatic groups, considered as stable carbon structure appeared as the temperature came closer to 600 °C, as well as in FT-IR. In rice materials, the peak assigned to SiO2, was observed in all biochars (400–800 °C) in FT-IR. We suppose that the pyrolysis at 600 °C creates the most recalcitrant character for carbon sequestration, meanwhile the pyrolysis at 400 °C produces the superior properties as a fertilizer by retaining volatile and easily labile compounds which promotes soil microbial activities.

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