Corrosion Resistance of Mild Steel Coated with Phthalimide-Functionalized Polybenzoxazines

Herein, we synthesized two new phthalimide-functionalized benzoxazine monomers, pPP-BZ and oPP-BZ, through Mannich reactions of 2-(4-hydroxyphenyl)isoindoline-1,3-dione (pPP) and 2-(2-hydroxyphenyl)isoindoline-1,3-dione (oPP), respectively, with p-toluidine and paraformaldehyde. The structures of these two monomers were confirmed using Fourier transform infrared (FTIR) and nuclear magnetic resonance spectroscopy. We used differential scanning calorimetry, FTIR spectroscopy, and thermogravimetric analysis to study the polymerization behavior and thermal stability of the monomers and their corresponding polybenzoxazines. Poly(pPP-BZ) and poly(oPP-BZ) were formed on mild steel (MS) through spin-coating and subsequent thermal curing polymerization. We used various corrosion testing methods to examine the effect of the curing temperature on the corrosion resistance of the coated MS samples in 3.5 wt.% aqueous solution of NaCl. Among our tested systems, the corrosion rate reached a low of 2.78 µm·Y−1 for the MS coated with poly(pPP-BZ)180 (i.e., the coating that had been cured at 180 °C); this value is much lower than that (4.8 µm·Y−1) reported for a maleimide-based benzoxazine compound (MI-Bz)/33 wt.% ACAT (amine-capped aniline trimer) blend. Thus, the incorporation of the imide functional group into the PBZ coatings is an effective strategy for affording high-performance corrosion resistance.

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Curing Kinetics and Thermal Stability of Epoxy Composites Containing Newly Obtained Nano-Scale Aluminum Hypophosphite (AlPO2)

Polymers ◽

10.3390/polym12030644 ◽

2020 ◽

Vol 12 (3) ◽

pp. 644 ◽

Cited By ~ 17

Author(s):

Farimah Tikhani ◽

Shahab Moghari ◽

Maryam Jouyandeh ◽

Fouad Laoutid ◽

Henri Vahabi ◽

...

Keyword(s):

Electron Microscopy ◽

Thermal Stability ◽

High Performance ◽

Frequency Factor ◽

Curing Temperature ◽

Heating Rates ◽

Scanning Calorimetry ◽

Nano Scale ◽

Aluminum Hypophosphite ◽

Thermal Stability Of

For the first time, nano-scale aluminum hypophosphite (AlPO2) was simply obtained in a two-step milling process and applied in preparation of epoxy nanocomposites varying concentration (0.1, 0.3, and 0.5 wt.% based on resin weight). Studying the cure kinetics and thermal stability of these nanocomposites would pave the way toward the design of high-performance nanocomposites for special applications. Scanning electron microscopy (SEM) and transmittance electron microscopy (TEM) revealed AlPO2 particles having domains less than 60 nm with high potential for agglomeration. Excellent (at heating rate of 5 °C/min) and Good (at heating rates of 10, 15 and 20 °C/min) cure states were detected for nanocomposites under nonisothermal differential scanning calorimetry (DSC). While the dimensionless curing temperature interval (ΔT*) was almost equal for epoxy/AlPO2 nanocomposites, dimensionless heat release (ΔH*) changed by densification of polymeric network. Quantitative cure analysis based on isoconversional Friedman and Kissinger methods gave rise to the kinetic parameters such as activation energy and the order of reaction as well as frequency factor. Variation of glass transition temperature (Tg) was monitored to explain the molecular interaction in the system, where Tg increased from 73.2 °C for neat epoxy to just 79.5 °C for the system containing 0.1 wt.% AlPO2. Moreover, thermogravimetric analysis (TGA) showed that nanocomposites were thermally stable.

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The Development of Rapidly Solidified Magnesium – Copper Ribbons

Archives of Metallurgy and Materials ◽

10.1515/amm-2016-0182 ◽

2016 ◽

Vol 61 (2) ◽

pp. 1083-1088

Author(s):

M. Pastuszak ◽

G. Cieślak ◽

A. Dobkowska ◽

J. Mizera ◽

K.J. Kurzydłowski

Keyword(s):

Corrosion Resistance ◽

Cooling Rate ◽

Melt Spinning ◽

Diffraction Method ◽

Electrode System ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Copper Addition ◽

Rapidly Solidified ◽

Thermal Stability Of

Abstract The aim of the present work was to plan and carry out an experiment consisting of amorphization of industrial magnesium alloy WE 43 (Mg - 4 Y - 3 RE - 0.5 Zr) modified by the copper addition. Investigated alloy modified with 20% of copper was rapidly quenched with the use of melt spinning technique. The effects of cooling rate on the structure and properties of the obtained material were extensively analyzed. The structure and phase analysis of samples were examined using X-ray diffraction method (XRD) while the thermal stability of the samples was determined by differential scanning calorimetry (DSC). Microstructure observations were also conducted. The microhardness tests (HV0.02) and corrosion resistance tests were carried out to investigate the properties of the material. Corrosion resistance measurements were held using a typical three-electrode system. As the result of the research, the effect of cooling rate on microstructure and properties of investigated alloy was determined.

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Heat-resistant and photoluminescent indole-based poly(ether sulfone)s

High Performance Polymers ◽

10.1177/0954008317701823 ◽

2017 ◽

Vol 30 (4) ◽

pp. 475-479 ◽

Cited By ~ 5

Author(s):

Wenxuan Wei ◽

Li Yang ◽

Guanjun Chang

Keyword(s):

Thermal Stability ◽

High Performance ◽

Proton Nuclear Magnetic Resonance ◽

Resonance Spectroscopy ◽

Condensation Polymerization ◽

High Glass Transition Temperature ◽

Scanning Calorimetry ◽

Good Thermal Stability ◽

High Performance Polymers ◽

Good Agreement

Indole-based poly(ether sulfone)s (PINESs), as novel high-performance polymers, have been obtained by the condensation polymerization of 4-hydroxyindole and hydroquinone with activated difluoro monomers via a catalyst-free nucleophilic substitution reaction. The structures of the polymers are characterized by means of Fourier transform infrared and proton nuclear magnetic resonance spectroscopy, and the results show good agreement with the proposed structures. Differential scanning calorimetry and thermogravimetric analysis measurements exhibit that polymers possess high glass transition temperature ( Tgs > 245°C) and good thermal stability with high decomposition temperatures ( Tds > 440°C). In addition, due to their special structure, PINESs are endowed with significantly strong photonic luminescence in N, N-dimethylformamide.

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Ti Microalloying Effect on Corrosion Resistance and Thermal Stability of Cu45Zr48Al7 Bulk Metallic Glass

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.490-495.3868 ◽

2012 ◽

Vol 490-495 ◽

pp. 3868-3873 ◽

Cited By ~ 1

Author(s):

Xiao Hong Yang ◽

Xi Peng Nie ◽

Jian Zhong Jiang

Keyword(s):

Thermal Stability ◽

Corrosion Resistance ◽

Metallic Glasses ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

X Ray ◽

Glass Forming ◽

Ti Addition ◽

Mould Casting ◽

Thermal Stability Of

Bulk metallic glasses (BMGs) of Cu45Zr48-xAl7Tix with x= 0, 1.5, and 3 at.% were prepared by copper mould casting. The corrosion resistance of the BMGs with different Ti contents was examined by potentiodynamic polarization tests and weight loss measurements in 1 N NaOH, 1 N H2SO4, 1 N H2SO4 + 0.01 N NaCl and 0.5 N NaCl solutions, respectively. The newly-developed BMGs’ corrosion resistance in Cl-- or both H+ and Cl--ions containing solutions can be greatly enhanced. The influence of Ti addition on glass forming ability (GFA) and thermal stability was investigated by x-ray diffraction and differential scanning calorimetry in detail. The alloy containing 1.5 at.% Ti exhibits the largest GFA, the critical size comes up to 10 mm in diameter.

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Interactions between Variable Frequency Microwave Underfill Processing and High Performance Packaging Materials

International Symposium on Microelectronics ◽

10.4071/isom-2013-wa21 ◽

2013 ◽

Vol 2013 (1) ◽

pp. 000461-000466 ◽

Cited By ~ 1

Author(s):

Mamadou Diobet Diop ◽

Marie-Claude Paquet ◽

Dominique Drouin ◽

David Danovitch

Keyword(s):

High Performance ◽

Flip Chip ◽

Coefficient Of Thermal Expansion ◽

Curing Temperature ◽

Variable Frequency ◽

Asymmetric Distribution ◽

Unexpected Result ◽

Scanning Calorimetry ◽

Negative Effect ◽

Curing Methods

Variable frequency microwave (VFM) has been recently proposed as an alternative underfill curing method that provides flip chip package warpage improvement as well as potential underfill cure time reductions. The current paper outlines how such advantages in VFM processing of underfill can be compromised when applied to high performance organic packages. VFM recipes for three underfill materials were developed by performing several VFM curing runs followed by curing rate measurements using the differential scanning calorimetry method. The VFM curing rate was seen to strongly dependent upon the underfill chemistry. By testing flip chip parts that comprised large and high-end substrates, we showed that the underfill material has negligible impact on VFM warpage with the major cause attributed to the coefficient of thermal expansion mismatch between the die and the substrate. Comparison between the convection and the VFM methods indicated two warpage tendencies that depended upon the VFM curing temperature. First, when both curing methods used comparably high temperatures, warpage increases up to about + 20% were found with VFM. This unexpected result was explained by the high-density Cu loading of the substrate which systematically carried heat generated by VFM energy from the die/underfill system to the substrate. Since this high-end substrate consists of sequential dielectric/Cu layers with asymmetric distribution of Cu, additional stresses due to local CTE mismatches between the Cu and the dielectric layers were induced within the substrate processed with VFM. Second, warpage reductions down to about − 22% were obtained at the VFM curing temperature of 110°C with a curing time similar to that of convection cure. This suggests that the negative effect of the local CTE mismatches were no longer at play at the lower VFM temperatures and that the significantly lower final cure temperatures produced lower total shrinkage of the die and the substrate. Finally, due to lower elastic moduli, the cured VFM parts showed better mechanical reliability with no fails up to 1500 cycles.

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Reactive Energetic Plasticizers Utilizing Cu-Free Azide-alkyne 1,3-dipolar Cycloaddition for In-Situ Preparation of Poly(THF-co-GAP)-Based Polyurethane Energetic Binders

10.20944/preprints201804.0197.v1 ◽

2018 ◽

Author(s):

Mingyang Ma ◽

Younghwan Kwon

Keyword(s):

Thermal Stability ◽

Dipolar Cycloaddition ◽

Resonance Spectroscopy ◽

Solid Propellants ◽

Scanning Calorimetry ◽

In Situ Preparation ◽

1H Nuclear Magnetic Resonance ◽

Energetic Plasticizers ◽

Thermal Stability Of

Reactive energetic plasticizers (REPs) coupled with hydroxy-telechelic poly(glycidyl azide-co-tetrahydrofuran) (PGT)-based energetic polyurethane (PU) binders for use in solid propellants and plastic-bonded explosives (PBXs) were investigated. The generation of gem-dinitro REPs along with a terminal alkyne stemmed from a series of finely designed approaches to not only satisfy the common demands as conventional energetic plasticizers but prevent the migration of plasticizers. The miscibility and rheological behavior of a binary mixture of PGT/REP with various REP fractions were quantitatively determined by differential scanning calorimetry (DSC) and rheometer, respectively, highlighting the promising performance of REPs in the formulation process. The kinetics on the distinct reactivity of propargyl vs. 3-butynyl species of REPs towards the azide group of the PGT prepolymer in terms of Cu-free azide-alkyne 1,3-dipolar cycloaddition (1,3-DPCA) was studied by monitoring 1H nuclear magnetic resonance spectroscopy and analyzing the activation energies (Ea) obtained using DSC. The thermal stability of the finally cured energetic binders with the incorporation of REPs indicated that the thermal stability of the REP/PGT-based PUs was maintained independently of the REP content. The tensile strength and modulus of the PUs increased with increasing the REP content. In addition, the energetic performance and sensitivity of REP and REP triazole species was predicted.

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Thermal behaviour of benzoxazine blends based on epoxy and cyanate ester

Polymers and Polymer Composites ◽

10.1177/09673911211059714 ◽

2021 ◽

Vol 29 (9_suppl) ◽

pp. S1475-S1485

Author(s):

Balaji Krishnasamy ◽

Hariharan Arumugam ◽

Mohamed Iqbal M ◽

Alagar Muthukaruppan

Keyword(s):

High Performance ◽

Analytical Techniques ◽

Cyanate Ester ◽

Resonance Spectroscopy ◽

Scanning Calorimetry ◽

Limiting Oxygen Index ◽

Polymeric Matrices ◽

Bisphenol F ◽

Degradation Temperature ◽

Cure Behaviour

In the present work, an attempt has been made to develop high-performance polymeric hybrid binary blends of epoxy/benzoxazine and benzoxazine/cyanate ester with varying weight percentages (25/75, 50/50 and 75/25 wt%) of resins, namely, bisphenol-F epoxy resin (DGEBF), benzoxazines [bisphenol–F/aniline (BF-a) and imidazole core-based bisphenol/aniline (IBP-a)] and cyanate ester [bisphenol-F bifunctional cyanate ester (BF-CE)]. The molecular structure, polymerisation temperature/cure behaviour, glass transition temperature (Tg) and thermal stability of the neat polymeric matrices and binary hybrid blends of polymeric matrices were characterised using different analytical techniques, viz. Fourier Transform infra-red spectroscopy (FTIR), Nuclear Magnetic Resonance spectroscopy (NMR), Differential Scanning Calorimetry (DSC) and thermogravimetric analysis (TGA). Among the binary hybrid blends, the lowest polymerisation temperatures (Tp) were noticed in the case of blends of epoxy/benzoxazine were 219°C for DGEBF/BF-a (25/75 wt%) and 170°C for DGEBF/IBP-a (25/75 wt%). Similarly, in the case of blends of benzoxazine/cyanate ester, the lowest values of Tp observed were 155°C and 153°C for BF-a/BF-CE (75/25 wt%) and IBP-a/BF-CE (75/25 wt%), respectively. The highest values of Tg observed for the blends of epoxy/benzoxazine were 175°C and 254°C for DGEBF/BF-a (25/75 wt%) and DGEBF/IBP-a (25/75 wt%), respectively. Whereas, the highest values of Tg observed in the case of blends of benzoxazine/cyanate ester were 234°C and 278°C for BF-a/BF-CE (25/75 wt%) and IBP-a/BF-CE (75/25 wt%), respectively. From the TGA results of blends, the maximum degradation temperature (Tmax) and limiting oxygen index (LOI) value calculated from the char yield, which ascertain that almost all the binary hybrid blends of epoxy/benzoxazine and benzoxazine/cyanate ester possess good flame retardant behaviour.

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Hydroxypropylation Reduces Gelatinization Temperature of Corn Starch for Textile Sizing

10.21203/rs.3.rs-192851/v1 ◽

2021 ◽

Author(s):

Yanqin Shen ◽

Yijun YAO ◽

Zhongliang Wang ◽

Hailiang Wu

Keyword(s):

High Performance ◽

Corn Starch ◽

Water System ◽

Hydroxyl Group ◽

Resonance Spectroscopy ◽

Gelatinization Temperature ◽

Step Method ◽

Scanning Calorimetry ◽

Raw Starch ◽

Substitution Level

Abstract A series of hydroxypropylated starch (HPS) that can be dissolved in water at 60-65℃ was obtained via two-step method in water system from corn starch. The structure and property of the HPS and its gelatinization temperature were characterized by Fourier transform infrared spectrometer (FTIR), nuclear magnetic resonance spectroscopy ( 1 H NMR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and transmission electron microscope (TEM). It was concluded that hydroxypropyl mainly bonded on the hydroxyl group at C 2 position from anhydroglucose unit of starch in the form of C-O-C, and the substitution level at C 6 position was slightly higher than that at C 3 position; and the crystallinity of starch decreased from 52.41% to 29.4% due to the introduction of hydroxypropyl and was confirmed by XRD. At the same time, the grooves on the surface of starch granules were observed by SEM. The above-mentioned two synergism promoted the permeation and transmission of water molecules in the starch microstructure. Moreover, the gelatinization temperatures and enthalpy of synthetic HPS was lower than that of raw corn starch, as further confirmed by DSC. This caused the HPS with a molar substitution greater than 0.1 soluble in water at 65℃, and the dissolution state was similar to that of at 95℃ (transmittance above 55%), as well as exhibited high slurry stability. Interestingly, compared with the raw starch, the HPS film showed excellent mechanical property at the relative humidity of 65%, which could be attributed to the hydrophilic ether bond and the flexible alkyl chain bonded on the structure of starch. This study will provide a new way for the preparation of high performance starch size for sizing yarn at medium low temperature.

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Preparation and Thermal Properties of Polybenzoxazine/TiC Hybrids

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.887-888.49 ◽

2014 ◽

Vol 887-888 ◽

pp. 49-52 ◽

Cited By ~ 8

Author(s):

Noureddine Ramdani ◽

Jun Wang ◽

Wen Bin Liu

Keyword(s):

Thermal Stability ◽

Differential Scanning Calorimetry ◽

Thermal Properties ◽

High Performance ◽

Phenolic Resin ◽

Scanning Calorimetry ◽

New Class ◽

Solution Blending ◽

Tic Nanoparticles ◽

Thermal Stability Of

In this work, typical polybenzoxazine, as new class of phenolic resin, has been used as a matrix for preparing a series of high performance hybrid materials using various amounts of titanium carbide (TiC) ranging between 0-10 wt% as fillers, via a solution blending technique. The thermal properties of bisphenol A-aniline base benzoxazine monomers (BA-a) and TiC mixtures have been studied by differential scanning calorimetry (DSC). The thermal stability of their cured hybrids has been tested by means of thermogravimetric analysis (TGA). The result showed that the glass transition temperature of the prepared composites increased with increasing the amount of TiC to reach a higher value at 194°C. Also, the incorporation of TiC nanoparticles has considerably improved the thermal stability of the hybrids including the char yield which increase by 50 % at 10 wt% TiC content.

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The effect of bismaleimide on thermal, mechanical, and dielectric properties of allyl-functional bisphthalonitrile/bismaleimide system

High Performance Polymers ◽

10.1177/0954008316667788 ◽

2016 ◽

Vol 29 (9) ◽

pp. 1016-1026 ◽

Cited By ~ 11

Author(s):

Mingli Jiang ◽

Xingqiang Zou ◽

Yumin Huang ◽

Xiaobo Liu

Keyword(s):

Mechanical Properties ◽

Dielectric Properties ◽

Composite Laminates ◽

Fiber Composite ◽

Wide Frequency Range ◽

Curing Temperature ◽

Scanning Calorimetry ◽

Thermal Stabilities ◽

Glass Fiber Composite ◽

Polymerization Behavior

Allyl-functional phthalonitrile (DBPA-Ph) and bismaleimide (BMI) have been considered as advanced composite-matrix resins applied in various fields. In this work, self-promoted polymerization behavior and processability of DBPA-Ph/BMI system were investigated in detail. To further reveal the effect of BMI on the properties of DBPA-Ph/BMI system, the blends and the prepolymers of DBPA-Ph/BMI were prepared in different proportions. Their curing and rheological behaviors were investigated by differential scanning calorimetry and dynamic rheological analysis. The results further confirmed the possible reaction mechanisms and demonstrated that DBPA-Ph/BMI prepolymers exhibited good processability, which included wide processing window (approximately 75°C), low melting viscosity (<0.2 Pa·s), and better reactivity. The copolymers exhibited satisfactory thermal stabilities ( T5% > 421°C, char yield at 600°C >70%). Moreover, the DBPA-Ph/BMI/glass fiber composite laminates were prepared and the effect of the curing temperature and BMI content on mechanical properties and dielectric properties were also investigated. The results show that the composite laminates exhibit favorable mechanical properties and weak frequency dependence of dielectric properties over a wide frequency range. Above all, the research on DBPA-Ph/BMI system could expand its applications in industry, especially in the areas, which require high temperature resistance and excellent mechanical and dielectric properties.

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