LIJUN CHEN^*, ZHEQING GONG, ZHENGRONG FU

Journal of Polymer Materials, Vol.40, No.3-4, pp. 157-164, 2023, DOI:10.32381/JPM.2023.40.3-4.3

Abstract The organic fluorine modified/containing cationic acrylic resin is prepared via solution polymerization technique using hexafluorobutyl methacrylate (HFMA) along with butyl acrylate (BA), methyl methacrylate (MMA), styrene (St), dimethylaminoethyl methacrylate (DMAEMA) and hydroxy propyl methacrylate (HPMA) as the comonomers, proprylene glycol monomethyl ether (PGME) as the solvent, and 2, 2-Azo-bis-iso-butyronitrile (AIBN) as the initiator. The synthesized resin in which fluorine atom is introduced into the polymer chains. The cathodic electrodeposition (CED) coatings were prepared by mixing the synthesized resin and blocked isocyanate. The influence of the amount of organic fluorine on the resin and the resultant CED coatings is investigated in… More >

Bengang Zhang^1,*, Antonio Pizzi^2,*, Mathieu Petrissans¹, Anelie Petrissans¹, Colin Baptiste¹

Journal of Renewable Materials, Vol.11, No.12, pp. 4097-4121, 2023, DOI:10.32604/jrm.2023.029761

Abstract Aminated tannins were prepared by reacting mimosa condensed tannin extract with ammonia yielding the substitution of many, if not all of the tannin hydroxyl groups with –NH₂ groups. A tannin-aminated tannin (ATT) particleboard coating was then prepared by reacting raw tannin extract with aminated tannin extract and thus cross-liking the two by substituting tannin’s hydroxyl groups with the –NH₂ groups on the aminated tannin to form –NH-bridges between the two. The resulting particleboard coating gave encouraging results when pressed at 180°C for 3 min. Conversely, the system in which tannin was reacted/cross-liked with urea (ATU) by a similar amination reaction… More >

Liuyu Yang¹, Peng Jiang¹, Tiejun Wang^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.010538

Abstract Air Plasma Sprayed (APS) Thermal Barrier Coatings (TBCs) have been widely used in land-based gas engines for enhancing the high temperature performance due to their outstanding thermal insulation and high durability. Introducing the segment cracks into APS-TBCs to enhance its durability has been quite attractive approaches nowadays. Qualitative conclusions have been drawn to explore the mechanisms on segment crack formation in the past decades. This article acts as a quantitative study of segment crack formation and crack density regulation mechanism in APS Yttria-Stabilized Zirconia (YSZ) TBCs with experimental observations and analytical calculations. An in-situ stress measurement method is developed through… More >

Biao Li^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.1, pp. 1-2, 2023, DOI:10.32604/icces.2023.09818

Abstract High-temperature coatings are extensively used in aircraft engines and industrial gas turbines to protect hot-section components from harsh operating environments [1]. Representative high-temperature coatings include thermal barrier coatings and environmental barrier coatings, which are applied to substrates made of superalloy and ceramic matrix composites, respectively. The durability of the coatings is of significant importance for the structural integrity of the components [2-4]. A segmented microstructure was widely used to improve the coatings' durability. A network of through-thickness vertical cracks is introduced into the outer layer of the coatings, which increases the compliance of the coatings and therefore reduces the interfacial… More >

Yue Yu^*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2681-2694, 2023, DOI:10.32604/fdmp.2023.028250

Abstract A triethylenetetramine epoxy mixture was synthesized through the reaction of a low-molecular-weight liquid epoxy resin with triethylenetetramine (TETA). Then triethyltetramine (TETA) was injected dropwise into a propylene glycol methyl ether (PM) solution for chain extension reaction. A hydrophilic and flexible polyether segment was introduced into the hardener molecule. The effects of TETA/DGEPG, reaction temperature and reaction time on the epoxy conversion of polyethylene glycol diglycidyl ether (DGEPG) were studied. In addition, several alternate strategies to add epoxy resin to the high-speed dispersion machine and synthesize MEA DGEBA adduct (without catalyst and with bisphenol A diglycidyl ether epoxy resin) were compared.… More >

Thomas J. Nelson, Lindsey Bultema, Neal Eidenschink, Dean C. Webster^*

Journal of Renewable Materials, Vol.1, No.2, pp. 141-153, 2013, DOI:10.7569/JRM.2013.634113

Abstract Bio-based polyols with high functionality were successfully synthesized by ring-opening epoxidized sucrose esters of soybean oil with methanol under acidic conditions, and were subsequently formulated with blocked isocyanates to form one package polyurethanes (1KPU). The bio-based polyols were characterized by gel permeation chromatography (GPC), Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (1 H-NMR) spectroscopy, and Brookfi eld viscosity. Bio-based coatings were prepared by formulating the polyols with blocked polyisocyanates based on isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI). Two types of bio-based polyols were synthesized and the ratio of NCO:OH functional groups was varied to explore the effect… More >

Dinesh Balgude, Anagha Sabnis^*

Journal of Renewable Materials, Vol.2, No.3, pp. 235-245, 2014, DOI:10.7569/JRM.2014.634115

Abstract Renewable resource-based hybrid crosslinker was successfully synthesized via sol-gel technology. The synthesis involved malenization of Cashew Nut Shell Liquid (CNSL) followed by its silane modifi cation and subsequent hydrolysis and condensation with tetraethyl orthosilicate (TEOS). The synthesized crosslinker was characterized by spectroscopic analysis (FT-IR, ¹ H-NMR, ¹³C-NMR and ²⁹Si-NMR) for structural elucidation. The crosslinker was further formulated in a conventional stoving system. Fully-cured coatings were obtained after stoving at 120°C for ½ hr and were then evaluated for physical, mechanical, chemical, optical, accelerated weathering, electrochemical and morphological properties. The incorporation of hybrid crosslinker in a conventional stoving system was observed… More >

Linchuan Liu¹, Jian Wu², Zhongwei Hu², Xiaochao Jin^1,*, Pin Lu¹, Tao Zhang², Xueling Fan^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.2, pp. 1219-1236, 2023, DOI:10.32604/cmes.2022.022221

Abstract A virtual wall thickness method is developed to simulate the temperature field of turbine blades with thermal barrier coatings (TBCs), to simplify the modeling process and improve the calculation efficiency. The results show that the virtual wall thickness method can improve the mesh quality by 20%, reduce the number of meshes by 76.7% and save the calculation time by 35.5%, compared with the traditional real wall thickness method. The average calculation error of the two methods is between 0.21% and 0.93%. Furthermore, the temperature at the blade leading edge is the highest and the average temperature of the blade pressure… More >

Jiacheng Qian¹, Chenqi Zou¹, Mengyan Zang^1,*, Shunhua Chen^2,3,*, Makoto Tsubokura⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.133, No.2, pp. 251-280, 2022, DOI:10.32604/cmes.2022.020738

Abstract The stone chip resistance performance of automotive coatings has attracted increasing attention in academic and industrial communities. Even though traditional gravelometer tests can be used to evaluate stone chip resistance of automotive coatings, such experiment-based methods suffer from poor repeatability and high cost. The main purpose of this work is to develop a CFD-DEM-wear coupling method to accurately and efficiently simulate stone chip behavior of automotive coatings in a gravelometer test. To achieve this end, an approach coupling an unresolved computational fluid dynamics (CFD) method and a discrete element method (DEM) are employed to account for interactions between fluids and… More >

Quan Wen¹, Fulei Jing^1,*, Changxian Zhang¹, Shibai Tang¹, Junjie Yang^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.132, No.2, pp. 361-391, 2022, DOI:10.32604/cmes.2022.019528

Abstract Thermally grown oxide (TGO) is a critical factor for the service life of thermal barrier coatings (TBC). Numerical simulations of the growth process of TGO have become an effective means of comprehensively understanding the progressive damage of the TBC system. At present, technologies of numerical simulation to TGO growth include two categories: coupled chemical-mechanical methods and mechanical equivalent methods. The former is based on the diffusion analysis of oxidizing elements, which can describe the influence of bond coat (BC) consumption and phase transformation in the growth process of TGO on the mechanical behavior of each layer of TBC, and has… More >