Morphology, Crystallinity and Thermal Properties of Polyamide 66/Polyoxometalate Nanocomposites Synthesised Via an in situ Sol/Gel Process

A multi-objective optimization of in situ sol-gel process was conducted in preparing oil palm fiber-reinforced polypropylene (OPF-PP) composite for an enhancement of mechanical and thermal properties. Tetraethyl orthosilicate (TEOS) and butylamine were used as precursors and catalysts for the sol-gel process. The face-centered central composite design (FCCD) experiments coupled with response surface methodology (RSM) has been utilized to optimize in situ silica sol-gel process. The optimization process showed that the drying time after the in-situ silica sol-gel process was the most influential factor on silica content, while the molar ratio of TEOS to water gave the most significant effect on silica residue. The maximum silica content of 34.1% and the silica residue of 35.9% were achieved under optimum conditions of 21.3 h soaking time, 50 min drying time, pH value of 9.26, and 1:4 molar ratio of TEOS to water. The untreated oil palm fiber (OPF) and silica sol-gel modified OPF (SiO2-OPF) were used as the reinforcing fibers, with PP as a matrix and maleic anhydride grafted polypropylene (MAgPP) as a compatibilizer for the fiber-reinforced PP matrix (SiO2-OPF-PP-MAgPP) composites preparation. The mechanical and thermal properties of OPF-PP, SiO2-OPF-PP, SiO2-OPF-PP-MAgPP composites, and pure PP were determined. It was found that the OPF-S-PP-MAgPP composite had the highest toughness and stiffness with values of tensile strength, Young’s modulus, and elongation at break of 30.9 MPa, 881.8 MPa, and 15.1%, respectively. The thermal properties analyses revealed that the OPF-S-PP-MAgPP exhibited the highest thermally stable inflection point at 477 °C as compared to pure PP and other composites formulations. The finding of the present study showed that the SiO2-OPF had the potential to use as a reinforcing agent to enhance the thermal-mechanical properties of the composites.

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Synthesis and Intermolecularly Mediated Assembly of Organic Pigment in Hybrid Coating Films

MRS Proceedings ◽

10.1557/proc-519-103 ◽

1998 ◽

Vol 519 ◽

Author(s):

Y. Yan ◽

Z. Duan ◽

D.-G. Chen ◽

S. Ray Chaudhuri

Keyword(s):

Sol Gel ◽

Hybrid Coating ◽

Hypsochromic Shift ◽

Hybrid Films ◽

Coating Films ◽

Organic Pigment ◽

Inorganic Hybrid ◽

Matrix Interactions ◽

Sol Gel Process

AbstractThe insoluble, strongly hydrogen bonded organic pigment of 3,6-bis-(4-chlorphenyl)-l,4- diketopyrrolo [3,4-c] pyrrole was transiently blocked by adding carbamate groups, and consequently incorporated into organic-inorganic hybrid matrices by a sol-gel process. The homo- (pigment-pigment) and hetero-intermolecular (pigment-matrix) interactions were found to control both the assembly and dispersion of pigment molecules in the hybrid coating films. A weaker interaction between matrices and pigment molecules results in aggregation of the carbamate pigment in the methyl-silicate films. A stronger interaction forms a homogenous dispersion and coloration of the phenyl-silicate films. The as-prepared methyl- and phenylsilicate films doped with the organic pigment were distinguished by a morphology change and a blue (hypsochromic) shift in absorption from 550 to 460 nm. Thermal treatment can remove the carbamate groups and in-situ form the organic pigment in the hybrid films.

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3C-SiC Nanowires In-Situ Modified Carbon/Carbon Composites and Their Effect on Mechanical and Thermal Properties

Nanomaterials ◽

10.3390/nano8110894 ◽

2018 ◽

Vol 8 (11) ◽

pp. 894 ◽

Cited By ~ 5

Author(s):

Hongjiao Lin ◽

Hejun Li ◽

Qingliang Shen ◽

Xiaohong Shi ◽

Tao Feng ◽

...

Keyword(s):

Shear Strength ◽

Thermal Properties ◽

Sol Gel ◽

Interlaminar Shear Strength ◽

Mechanical And Thermal Properties ◽

Initial Oxidation ◽

Sic Nanowires ◽

Out Of Plane ◽

Interlaminar Shear

An in-situ, catalyst-free method for synthesizing 3C-SiC ceramic nanowires (SiCNWs) inside carbon–carbon (C/C) composites was successfully achieved. Obtained samples in different stages were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Raman scattering spectroscopy. Results demonstrated that the combination of sol-gel impregnation and carbothermal reduction was an efficient method for in-situ SiCNW synthesis, inside C/C composites. Thermal properties and mechanical behaviors—including out-of-plane and in-plane compressive strengths, as well as interlaminar shear strength (ILLS) of SiCNW modified C/C composites—were investigated. By introducing SiCNWs, the initial oxidation temperature of C/C was increased remarkably. Meanwhile, out-of-plane and in-plane compressive strengths, as well as interlaminar shear strength (ILLS) of C/C composites were increased by 249.3%, 109.2%, and 190.0%, respectively. This significant improvement resulted from simultaneous reinforcement between the fiber/matrix (F/M) and matrix/matrix (M/M) interfaces, based on analysis of the fracture mechanism.

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Fabrication of sulfonated poly(ether ether ketone)-based hybrid proton-conducting membranes containing carboxyl or amino acid-functionalized titania by in situ sol–gel process

Journal of Power Sources ◽

10.1016/j.jpowsour.2014.11.132 ◽

2015 ◽

Vol 276 ◽

pp. 271-278 ◽

Cited By ~ 50

Author(s):

Yongheng Yin ◽

Tao Xu ◽

Guangwei He ◽

Zhongyi Jiang ◽

Hong Wu

Keyword(s):

Amino Acid ◽

Sol Gel ◽

Proton Conducting ◽

Ether Ether Ketone ◽

Poly Ether Ether Ketone ◽

Sol Gel Process ◽

Ether Ketone ◽

Conducting Membranes ◽

Sulfonated Poly

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Preparation of the polymerizable titania oriented to 3D printing and the laser-induced crystallization

Rapid Prototyping Journal ◽

10.1108/rpj-03-2017-0041 ◽

2018 ◽

Vol 24 (9) ◽

pp. 1421-1427 ◽

Cited By ~ 2

Author(s):

Feng Liu ◽

Shaoai Xie ◽

Yan Wang ◽

Jianjun Yu ◽

Qinghua Meng

Keyword(s):

3D Printing ◽

Sol Gel ◽

Crystal Form ◽

Tetrabutyl Titanate ◽

Content Type ◽

Functional Additives ◽

Sol Gel Process ◽

Photosensitive Resin ◽

Induced Crystallization

PurposeThe titania (titanium dioxide) is one of the important functional additives in the photosensitive resin and encounters the problem of stabilization in the photosensitive resin for 3D printing. This study aims to achieve enhancement in stabilization by preparation of the polymerizable titania andin situlaser-induced crystallization during 3D printing.Design/methodology/approachA type of polymerizable titania (AAEM@TiO2) was designed and prepared from tetrabutyl titanate (TBT) and 2-(acetoacetoxy)ethyl methacrylate (AAEM) via the sol–gel process, which was characterized by Fourier-transform infrared (FTIR) spectra, ultraviolet–visible (UV-Vis) spectra, surface bonding efficiency (SBE) and settling height (H). AAEM acted on both bonding to the titania and polymerization with the monomer in resin for stabilization. The polymerizable titania could be converted to the pigmented titania by means of laser-induced crystallization. The photosensitive resin was then formulated on the basis of optimization and used in a stereolithography apparatus (SLA) for 3D printing.FindingsThe stabilization effect of AAEM on TiO2was achieved and the mechanism of competition in the light-consuming reactions during photocuring was proposed. The ratio of nAAEM/nTBTin AAEM@TiO2, the concentration of AAEM@TiO2and photoinitiator (PI) used in the photosensitive resin were optimized. The anatase crystal form was indicated by X-ray diffraction (XRD) and clustering of nanocrystals was revealed by scanning electron microscopy (SEM) after SLA 3D printing.Originality/valueThis investigation provides a novel method of pigmentation by preparation of the polymerizable titania andin situlaser-induced crystallization for SLA 3D printing.

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