Triethoxy Silane Coupling Agent Research Articles

Developing Crumbed Rubber Tires / Epoxy Composite, by Surface Treatment with Different Silane Coupling Agents

Converting used tries to useful materials and avoiding harmful effects of accumulation used tires, is a great economic and environmental issue. Using of crumbing rubber of used tires CRT as filler materials shows declining in mechanical properties of CRT/polymer composites as weak bonding between CRT and polymeric matrices. This work include, CRT surface treating by three kinds of silane coupling agent, Trimethoxysilyl propyl methacrylate, 3-chloropropyl triethoxy silane and Silicic acid, before using as filler materials in epoxy matrix. 10 wt. % of non-treated and treated CRT/epoxy composite specimens have been prepared and tested to evaluate effect of CRT surface treatment into composite mechanical properties. The results show that modulus of elasticity, tensile strength, and fracture toughness of treated CRT/epoxy composite could improve by 56%, 30%, 36% respectively comparing with that of non-treated CRT/epoxy, after treating by 3-chloropropyl triethoxy silane coupling agent, whereas surface treating by other types of silane coupling agents could produce less mechnical improvement but still better that of non-treated.

Multi-stimuli-responsive magnetic hydrogel based on Tragacanth gum as a de novo nanosystem for targeted chemo/hyperthermia treatment of cancer

A novel magnetic pH- and redox-responsive drug delivery system (DDS) based on natural Tragacanth gum (TG) was developed for targeted chemo/hyperthermia treatment of cancer. Firstly, acrylic acid (AA) monomer was grafted onto a maleic anhydride-functionalized TG macromonomer (MATGM) through a free radical copolymerization. Magnetic nanoparticles (MNPs) were synthesized through chemical co-precipitation, and subsequently were modified using (3-aminopropyl)triethoxysilane coupling agent. The magnetic stimuli-responsive hydrogel for targeted cancer therapy was synthesized by the incorporation of modified-MNPs and folic acid (FA), and simultaneous crosslinking of TG-g-PAA copolymer using cystamine (Cys) moiety. Doxorubicin hydrochloride (Dox) was loaded into the fabricated magnetic hydrogel (MH), and its release was studied under pH- and redox-triggered condition. The anti-cancer activity of the Dox-loaded DDS was examined against MCF7 cells through MTT assay by both chemotherapy and chemo/hyperthermia therapy approaches. It was revealed that the developed DDS has higher anti-cancer activity (~ 24%) owing to its “smart” and slow drug release behavior as well as synergic effect of hyperthermia therapy. A novel magnetite pH- and redox-responsive drug delivery system (DDS) based on natural Tragacanth gum (TG) was design and developed for targeted chemo/hyperthermia therapy of solid tumors.

Effect of (3‐aminopropyl)triethoxysilane coupling agent on characteristics and mechanical properties of polylactic acid/jute fiber biocomposite

AbstractBiocomposites based on polylactic acid (PLA) and jute fiber (JF) (90/10 wt.%/wt.%) were prepared by melt mixing method in the internal Poly Haake mixer. Before preparing PLA/JF biocomposites, JF was cut into the shorter fiber with 1‐2 mm in length and was modified by 1, 5 and 10 wt.% of (3‐aminopropyl)triethoxysilane (APTES). Fourier transform infrared (FTIR) spectroscopy was conducted to evaluate the presence of APTES on the JF surface. The mechanical properties of PLA/JF biocomposites including tensile strength, Young's modulus and impact strength were investigated. It is found that APTES improved remarkably the mechanical properties and reached the maximum values for sample using 5 wt.% APTES. The composites using modified JF showed the higher thermal stability in comparison to the unmodified sample. SEM micrographs of the fractured surface area exhibited the better adhesion between JF and PLA matrix after modification.

Evaluation of thermal and flame properties of HDPE-MWCNT-SiO2 nanocomposites

High-density polyethylene (HDPE) composites reinforced with multiwalled carbon nanotubes (MWCNTs) and nano-silicon dioxide (SiO2) fillers were evaluated for flame retardancy and thermal properties for cable and wire applications. In this study, the filler percentages of MWCNT and nano-SiO2 have varied from 0 to 5 wt% in HDPE composite with polyethylene-grafted glycidyl methacrylate compatibilizer and 3-aminopropyl triethoxy silane coupling agent. Addition of MWCNT’s and nano-SiO2 to the HDPE composite is observed to enhance the limiting oxygen index and char formation. Cone calorimeter results also show a 53% reduction in the peak heat release rate of the HDPE composite with 5 wt% of MWCNT. The existence of synergism between the uniformly dispersed MWCNT and nano-SiO2 has been verified using Finite Element Method (FEM)-based thermal simulations.

Comparative study of dielectric and mechanical properties of HDPE-MWCNT-SiO2 nanocomposites

Multiwalled carbon nanotubes (MWCNT⿿s) and Nano-Silicon dioxide (SiO2) reinforced HDPE composites have been developed. The MWCNT and Nano- SiO2 filler content was varied up to 5wt% in HDPE with the addition of Polyethylene grafted glycidyl methacrylate compatibilizer and 3-aminopropyl triethoxy silane coupling agent. The dielectric and mechanical properties of the HPDE nanocomposites have been investigated in this study. Addition of MWCNT and Nano-SiO2 are observed to enhance the tensile strength and modulus of the nano-composites. The electrical properties like breakdown voltage and volume resistivity showed improvement with the addition of Nano-SiO2.

Mechanical Properties of Wood Flour Reinforced High Density Polyethylene Composites with Basalt Fibers

Basalt fibers (BFs) were surface-treated with a vinyl triethoxy silane coupling agent to improve the mechanical properties of wood fiber-reinforced high density polyethylene (HDPE) composites. Basalt fibers were characterized with SEM and FT-IR. The effects of the basalt fiber content and apparent morphology on the mechanical properties of the hybrid composites were investigated in this paper. The results show that the BF coated with the vinyl triethoxy silane coupling agent resulted in an improvement in mechanical properties due to the increased interfacial compatibility between the BF and HDPE. The flexural strength and impact properties significantly increased with 4 wt.% modified basalt fibers. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6441

Mechanical properties of uniaxial natural fabric Grewia tilifolia reinforced epoxy based composites: Effects of chemical treatment

The effects of chemical treatment on the mechanical, morphological, and chemical resistance properties of uniaxial natural fabrics, Grewia tilifolia/epoxy composites, were studied. In order to enhance the interfacial bonding between the epoxy matrix and the Grewia tilifolia fabrics, two different types of treatment: alkali treatment (5 % NaOH) and (3-aminopropyl)-triethoxysilane coupling agent (CA), were used. The epoxy composites containing 0–15 wt% of Grewia tilifolia fabric were prepared by hand lay-up technique, at room temperature. The tensile and flexural properties of the untreated, alkali-treated and coupling agent treated Grewia tilifolia reinforced epoxy composites were determined as a function of fabric loading. The 9 % wt Grewia tilifolia fabric reinforced epoxy composites showed improved tensile and flexural modulii when compared to the neat epoxy matrix. Significant improvement in the mechanical properties was obtained when both alkali and coupling agent treated fabrics were used as reinforcement. Morphological studies demonstrated that better adhesion between the fabrics and the matrix was achieved especially when the alkali-treated and coupling agent treated Grewia tilifolia fabrics were used in the composites. For the water absorption and chemical resistance studies, various solvents, acids and alkalis were used on the epoxy composites. This study has shown that Grewia tilifolia fabric/epoxy composites are promising candidates for structural applications, where high strength and stiffness are required.

Evaluation of the tensile strength of polypropylene-based composites containing glass wool

In this study, Glass wool which is mainly applied to heat and acoustic insulation was used as reinforcement materials. The composite material samples consisting of glass wool, polypropylene, and maleic anhydride grafted polypropylene were synthesized and the tensile strengths were evaluated. The treatment of glass wool with 3-amino propyl triethoxy silane coupling agent together with epoxy film former enhanced the tensile strength of the composite samples including the glass wool and the tensile strength reached to the same level of the conventional composite samples including chopping continuous glass fiber. Therefore, we concluded that glass wool has a good potential as a reinforcing material in thermoplastic composites.

Preparation and characterization of UV‐cured hybrid coatings by triethoxysilane‐modified dimethacrylate based on bisphenol‐s epoxy

AbstractNovel hybrid oligomers based on a UV‐curable bisphenol‐S epoxy dimethacrylate (DBSMA) were synthetized. DBSMA was modified with various amount of (3‐isocyanatopropyl)triethoxysilane coupling agent. The modification degree of the hybrid oligomer was varied from 0 to70 wt %. The photopolymerization kinetics was monitored by a real‐time infrared spectroscopy. The conversion and rate of hybrid coatings increased with the increase in modification degree. UV‐curable, hard, and transparent organic–inorganic hybrid coatings were prepared. They were performed by the analyses of various properties such as surface and mechanical properties. Results from the mechanical measurements showed that the properties of hybrid coatings improved with the increase in modification degree. The thermal behavior of coatings was also investigated. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Synthesis and characterization of some polyacrylate/montmorillonite nanocomposites by in situ emulsion polymerization using redox initiation system

AbstractIntercalated modification of Montmorillonite clay (MMT) with three different amino acids—Alanine, Leucine, and Phenylalanine—in the presence of hydrochloric acid followed by surface modification by methyl triethoxy silane coupling agent to produce double modified Montmorillonite clay which is characterized by X‐ray diffraction (XRD) and Thermogravimetric analysis (TGA). The data shows an increase in d‐spacing of modified clay as a result of cationic exchange. Double modified MMT clay was used in the preparation of Polyacrylate/clay nanocomposites by using an in situ redox emulsion polymerization of polyglycidylmethacrylate (PGMA) and polymethylmethacrylate (PMMA). The structure and properties of the prepared nanocomposites were achieved by XRD, TGA, and SEM. The results show that all weight loses temperatures for the nanocomposite samples are higher than that of pure polymer in both PGMA and PMMA. It is also obvious that the increasing in the clay content plays an effective role in the increasing of thermal stability of these materials. SEM shows that the clay is more homogenously dispersed in PMMA than in PGMA matrix. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Immobilizing a Fluorescent Dye Offers Potential to Investigate the Glass/Resin Interface

Silane coupling agents are commonly applied to glass fibers to promote fiber/resin adhesion and enhance durability in composite parts. In this study, a coupling agent multilayer on glass was doped with trace levels of the dimethylaminonitrostilbene (DMANS) fluorophore. The fluorophore was immobilized on the glass surface by tethering the molecule to a triethoxy silane coupling agent, creating the DMANS/silane coupling agent molecule (DMSCA). DMSCA was then diluted with commonly used coupling agents and grafted to a glass microscope coverslip to create a model composite interface. A 53-nm blue shift in fluorescence from the immobilized DMSCA can be followed during cure of an epoxy resin overlayer, giving this technique potential to monitor the properties of the fiber/resin interface during composite processing. Contact angle measurements on these coupling agent layers were similar in the presence or absence of the DMSCA molecule, suggesting that trace levels of the fluorescent probe did not affect the structure of the layer. The immobilized DMSCA molecule behaved similarly to the DMANS precursor in solution. Both showed longer wavelength fluorescence in more polar environments.

Effect of coupling agent and absorbed moisture on the tensile properties of a thermoplastic RRIM composite

AbstractThe effect of introduction of a silane coupling agent and absorbed moisture (i.e., equilibrium hygroscopic state) on the tensile properties of a thermoplastic reinforced reaction injection molding (RRIM) composite, having a fiber volume fraction of 0.33, was evaluated. The composite was produced by anionically polymerizing caprolactam monomer within a continuous strand (swirl) glass fiber mat using a RRIM method. In addition to the expected strong dependence of the composite tensile stiffness and strength on introduction of 1.5 wt % (based on the total weight of glass fibers) of γ‐amino propyl triethoxy silane coupling agent, the effect of the mode of application of the coupling agent on the resultant composite properties, under tensile loading, was observed to be insignificant in the dry state but quite important in the wet state. Microscopic examination of the fracture surfaces revealed a three‐stage tensile failure mechanism that is associated with debonding at low strains of the fibers, fiber failure (at the weakest point), and pull‐out of the fibers resulting in catastrophic failure, at the ultimate tensile strain, of the composite.