Propyl Trimethoxyl Silane Research Articles

Preparation of hydrophobic organic-silicanano composites

ABSTRACTIn this paper, we use silica nanoparticles modified by methacryloxy propyl trimethoxylsilane (KH570) as the core material, and employ polymers including hexafluorobutyl methacrylate (HFMA), dodecafluoroheptyl methacrylate (DFMA) and acrylic ester as the shell materials to prepare the hydrophobic inorganic–organic hybrid nanocomposites with a seed emulsion polymerization strategy. The size, morphologyandproperties of the core-shell structured nanoparticles are investigated by TEM and SEM. The results showthat the polymer nanocomposite has three concentric layers with silica nanoparticles in the center, acrylic polymer as the internal shell and fluorosilicone polymer as the outmost shell. By controlling the ratio of the silica nanoparticles and monomers, we can achieve each composite particle has the core-shell structure with silica nanoparticles as the core and the thin layer of fluorosilicone polymer as the shell. Compared with the traditional polymer film, the nanocomposite film shows a hydrophobic property with a contact angle of up to 100 degree. Therefore, it is feasible to prepare hydrophobic organic–inorganic nanocomposites using the method proposed here.

Photogenerated cathodic protection and invalidation of silane/TiO2 hybrid coatings

Silane/TiO2 hybrid coatings were prepared on 304 stainless steel (304 SS) by a simple dipping method, where the silane is d-γ-methylacryloxy propyl trimethoxyl silane (CH2=C(CH3)COO(CH2)3Si(OCH3)3, MPMS). The photogenerated cathodic protection and invalidation of the hybrid coatings were evaluated by microstructure and electrochemical characterization. The coupling agent MPMS reduced the agglomeration of the nanosized TiO2 powders and promoted the adhesion of the coatings. Barrier protection of the coupled metal was promoted for the hybrid coatings in a short corrosion time. However, MPMS decreased the carrier concentration of the TiO2 electrode due to the large interface resistance. As a result, the corrosion potential shifted positively and the photogenerated cathodic protection decreased. In long-time corrosion, the hybrid coatings became invalid because of the accumulation of electropositive holes that may weaken the Ti–O bond and destroy the barrier effect.

Organic-Inorganic Hydrophobic Nanocomposite Film with a Core-Shell Structure.

A method to prepare novel organic-inorganic hydrophobic nanocomposite films was proposed by a site-specific polymerization process. The inorganic part, the core of the nanocomposite, is a ternary SiO2–Al2O3–TiO2 nanoparticles, which is grafted with methacryloxy propyl trimethoxyl silane (KH570), and wrapped by fluoride and siloxane polymers. The synthesized samples are characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectrscopy, X-ray diffractometry (XRD), contact angle meter (CA), and scanning electron microscope (SEM). The results indicate that the novel organic-inorganic hydrophobic nanocomposite with a core-shell structure was synthesized successfully. XRD analysis reveals the nanocomposite film has an amorphous structure, and FTIR analysis indicates the nanoparticles react with a silane coupling agent (methacryloxy propyl trimethoxyl silane KH570). Interestingly, the morphology of the nanoparticle film is influenced by the composition of the core. Further, comparing with the film synthesized by silica nanoparticles, the film formed from SiO2–Al2O3–TiO2 nanoparticles has higher hydrophobic performance, i.e., the contact angle is greater than 101.7°. In addition, the TEM analysis reveals that the crystal structure of the particles can be changed at high temperatures.

Comparison with adsorption of Re (VII) by two different γ-radiation synthesized silica-grafting of vinylimidazole/4-vinylpyridine adsorbents

Two silica gel based adsorbents for Re (VII), i.e. SS-MPTS-VIMH and SS-MPTS-VPQ, were synthesised. Silica gel was used as the matrix for γ-radiation grafting, and the monomer of 1-vinyl imidazole (VIM) and 4-vinylpyridine (4-VP) was grafted onto the silica silanized by methacryloxy propyl trimethoxyl silane, respectively. A VIM concentration of 2molL−1 and an absorbed dose of 30kGy were the optimal grafting conditions for adsorbent SS-MPTS-VIM, and a 4-VP concentration of 4molL−1 and an absorbed dose of 40kGy were the optimal grafting conditions for adsorbent SS-MPTS-VP. At the certain condition, the grafting yield of SS-MPTS-VIM was 30.1% and that of SS-MPTS-VP was 21.0%. The adsorption capacity of adsorbent SS-MPTS-VIMH was 145.99mgg−1 and that of SS-MPTS-VPQ was 71.08mgg−1 according to the Langmuir model. The adsorbent SS-MPTS-VPQ had better adsorption properties of acid resistance and anti-interference than SS-MPTS-VIMH. Dynamic column experiments showed that protonated adsorbent SS-MTPS-VIMH could be recycled with good performance while quaternized adsorbent SS-MPTS-VPQ could not. The adsorbent SS-MPTS-VIMH belongs to weak anion exchange adsorbent and SS-MPTS-VPQ belongs to strong anion exchange adsorbent. This study paves a way to the synthesis and application of a novel silica base adsorbents for Re (VII).

Preparation of acrylate copolymer modified byTiO2nanoparticles with excellent photo‐oxidative stability for application in ancient ivory conservation

ABSTRACTIn this work, acrylate copolymer has been fabricated by graft copolymerization of acrylate monomer (EMA:EA is 70:30) with functional TiO2nanoparticles, which was surface‐modified by the silane coupling agent methacryloxy propyl trimethoxyl silane (KH570) to attach active ends. The structure and properties of the copolymer were characterized by FT‐IR, FE‐SEM, differential scanning calorimetry, thermogravimetric analysis, ultraviolet‐visible spectra, and discoloration. Characterization revealed that functional TiO2particles were grafted onto the chain of the acrylate copolymer and the acrylate copolymer showed excellent photo‐oxidative stability and transparency. The acrylate copolymer was applied to protect and consolidate ancient ivory by surface coating without destruction of chemical structure. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 43291.

Preparation of PMMA grafted calcium carbonate whiskers and its reinforcement effect in PVC

In this study, calcium carbonate (CaCO3) whiskers were grafted with poly(methyl methacrylate) (PMMA) by in situ emulsion polymerization using γ‐methacryloxy propyl trimethoxyl silane (γ‐MPS) as a coupling agent, and the properties of resultant whisker were determined using Fourier transform infrared (FTIR) spectroscopy, energy dispersive spectroscopy (EDS), X‐ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The results show that PMMA has been successfully grafted onto the surface of CaCO3 whiskers and the maximum grafting degree (Gd) is 3.75%. The scanning electron microscopy (SEM) micrographs of the tensile‐fractured surfaces show that modified CaCO3 whiskers have strong interfacial adhesion to the poly(vinyl chloride) (PVC) matrix. The tensile strength increases from 44.0 MPa for PVC composite with unmodified whisker to 49.5 MPa for that with grafted whisker. The dynamic mechanical analysis (DMA) and TGA results indicate that the composites reinforced by modified CaCO3 whiskers have much higher modulus, glass transition temperature, and better thermal stability than their counterparts reinforced by unmodified CaCO3 whiskers. POLYM. COMPOS., 38:2753–2761, 2017. © 2015 Society of Plastics Engineers

Synthesis and characterization of novel acrylic comb-shaped copolymer containing long fluorinated side chains

A novel acrylic comb-shaped copolymer containing long fluorinated side chains (ACCLF) was successfully synthesized by conventional radical polymerization of a novel mono-methacryloyloxy terminated fluorinated macromonomer (PHFBMA-MA), methyl methacrylate (MMA), isobutyl acrylate (IBA), and γ-methacryl propyl trimethoxyl silane (MPTS). GPC, FTIR, and 1H-NMR data successfully verified the synthesis. The influence of both the molecular weight and concentration of PHFBMA-MA on the surface properties of ACCLF films was investigated. By increasing both the concentration and the molecular weight of PHFBMA-MA, the surface energy of the films decreased and contact angle increased. The surface energy of ACCLF-1/3-8 with just 8 wt% PHFBMA-MA-1/3 (20.68 mN/m) was almost the same as that of the neat PHFBMA (20.36 mN/m), indicating the high efficiency of the macromonomer in lowering the surface energy of the comb-shaped copolymer. The surface composition of ACCLF was characterized and quantified by X-ray photoelectron spectroscopy (XPS). XPS results strongly confirmed that, at the same fluorinated content, long fluorinated chains modified film (9.36 % fluorine content for ACCLF-1/3-4 and 8.19 % fluorine content for ACCLF-1/6-4) showed higher fluorine concentration at the top surface than that of ACSF-4 modified film (1.52 %). ACCLF films also had excellent adhesion [on glass, tin plate, and polycarbonate (PC)], pencil hardness, and thermal properties. The novel ACCLF prepared via conventional radical polymerization not only had excellent comprehensive performance, but also has prominent potential application in large-scale industrialization.

Synthesis and Morphology Control of Janus Nanomaterials

We propose a facile method to synthesize Janus nanomaterials by seed interfacial sol-gel process against a polystyrene (PS) hollow sphere using three precursor silanes, (3-aminopropyl) triethoxysilane (APTES), methacryloxy propyl trimethoxyl silane (MPS) and tetraethyl orthosilicate (TEOS). The sol-gel process starts from the exterior surface of the seed sphere. Janus nanomaterials were formed in situ onto the seed sphere surface after a self-organized sol-gel process, which possess 3-methacryloxypropyl- and amine-groups terminated at both sides of the shell. Morphology of the Janus nanomaterials could be tunable from intact shell, nanosheet, porous nanosheet and individual nanoparticles by controlling pH, precursor amount and the fraction of binary emulsifier system. After the removal of PS by dissolution under ultrasonication, Janus nanoparticles were eventually achieved. This method is attractive owing to the easiness to continuously adjust morphology of the Janus nanomaterials. On the other hand, composition of the nanomaterials is also flexibly tunable by using different precursors. What's more, the Janus nanomaterials can derive other Janus ones after selective modification and favorable growth of desired materials onto the corresponding side.

Novel Enhanced Acrylic Denture Base Powder by Incorporating with PMMA-Modified Ag/NaZr<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub> through <i>In Situ</i> Suspension Polymerization

A kind of novel antibacterial denture base powder incorporated with PMMA-modified nanoAg/NaZr2(PO4)3(CBD-300) was prepared by in-situ suspension polymerization and the flexural properties of denture base resin was investigated. CBD-300 was silanized by 3-methacryloxy propyl trimethoxyl silane (γ-MPS), and thenγ-MPS-CBD-300 was grafted with poly (methyl methacrylate) (PMMA) to prepare M-CBD-300 which has a good compatibility with the denture base resin. Denture base powders with different addition of M-CBD-300 were prepared by in-situ suspension polymerization. Thermal gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and water contact angle were used to characterize M-CBD-300. The size of denture base powder was observed by optical microscope. Universal testing apparatus and scanning electron microscope (SEM) were used to investigate flexural properties of denture base resin samples. The results showed that the surface of M-CBD-300 was successfully modified by PMMA, and the incorporation of M-CBD-300 leads to increasing of the denture base powder size. The flexural properties of the denture base resin samples prepared with our antibacterial denture base powders were enhanced greatly compared with the blank sample.

High‐mechanical‐strength ferrohydrogels with a magnetically dispersed phase as multifunctional crosslinkers

ABSTRACTIn this article, we report a facile strategy for preparing high‐mechanical‐strength ferrohydrogels containing magnetic nanoparticles homodispersed by a thermodynamically stable Pickering emulsion (PE). After the monomers were mixed with the PE, including methacryloxy propyl trimethoxyl silane emulsified by ferric oxide (Fe2O3) nanoparticles as the dispersed phase, hydrogels were synthesized by free‐radical polymerization. In contrast to conventional hydrogels crosslinked by a molecular crosslinker, in our new approach, the magnetic PE particles served as individual, multifunctional crosslinkers. Characterizations of the swelling behavior, the mechanical properties, and other properties indicated that our ferrohydrogels exhibited outstanding physical performances that were superior to those of traditional hydrogels and magnetic responsiveness. These ferrohydrogels may have applications in soft and controllable actuators. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41950.

Fabrication of Siloxane Hybrid Material With High Adhesion and High Refractive Index for Light Emitting Diodes (LEDs) Encapsulation

A novel inorganic-organic siloxane hybrid material with self-adhesion ability and high refractive index for high-power light emitting diodes (LEDs) encapsulation is introduced. Under the catalysis of an anion exchange resin, the hybrid material was synthesized by a sol-gel condensation process from methacryloxy propyl trimethoxyl silane (MPTS), γ-(2, 3-epoxypropoxy)propytrimethoxysilane (EPTS) and diphenylsilanediol (DPSD). This hybrid material was characterized by Fourier-transform infrared spectroscopy and 1H-NMR. The resin-type encapsulation material was then prepared by hydrosilylation of the newly synthesized inorganic-organic siloxane hybrid material and methylphenyl hydrogen-containing silicone resin. The cured silicone resin-type encapsulation material can be used as a LEDs encapsulant, owing to high refractive index (n = 1.544), high transparency, appropriate hardness, and excellent thermal stability, as well as good adhesive strength between the encapsulating material and the substrate of LED lead frame.

Synthesis and Properties of Polyacrylate Hybrid Latexes Containing Fluorine and Silicon

In this paper, a series of fluoro-silicone -containing acrylate emulsion (FSiAE) have been prepared through pre-emulsified semi-continuous seed emulsion method with OP-10, sodium dodecyl sulfate (SDS) as the emulsifier, ammonium persulfate (APS) as the initiator, methyl methacrylate (MMA) and butyl acrylate (BA) as the main monomers, 2,2,3,4,4,4-hexafluorobutyl methacrylate (G02) and methacryloxy propyl trimethoxyl silane (KH-570) as the functional monomers, The effect of the content of fluoro-silicone -containing monomer on the properties of acrylate emulsion and their films, such as the contact angle, water absorption, viscosity and hardness was investigated. The results show that functional monomers had effectively copolymerized with acrylic monomers, and the introduction of fluoro-silicone into the polyacrylate emulsion system did make the viscosity of the emulsion increased, the water absorption and the surface energy of the film decreased.

Synthesis of an adhesion‐enhancing polysiloxane containing epoxy groups for addition‐cure silicone light emitting diodes encapsulant

Addition‐cure silicone resin is considered as a good choice for light emitting diodes (LEDs); however, it has very poor adhesion to the substrate, which limits its practical application. A novel polysiloxane with self‐adhesion ability and higher refractive index for the encapsulating of high‐power LEDs is prepared and characterized. This polysiloxane containing vinyl groups, phenyl groups, and epoxy groups was synthesized by a sol‐gel condensation process from methacryloxy propyl trimethoxyl silane, γ‐(2,3‐epoxypropoxy)propytrimethoxysilane, and diphenylsilanediol under the catalysis of an anion exchange resin. Then, the resin‐type encapsulation material was prepared by hydrosilylation of methylphenyl hydrogen‐containing silicone resin and the newly synthesized polysiloxane material. The novel polysiloxane was characterized by 1H‐NMR and Fourier transform infrared spectroscopy. On the basis of higher refractive index, higher transparency, excellent thermal stability, and appropriate hardness, as well as good adhesive strength between the encapsulating material and the LED lead frame (polyphthalamide), the curable silicone resin‐type encapsulation material can be used as an encapsulant for LEDs. Copyright © 2014 John Wiley & Sons, Ltd.

Emulsifier-Free Core-Shell Hybrid Latexes from Castor Oil-Based Waterborne Polyurethane and Polyacrylate Containing Fluorine and Silicon

The core-shell polyurethane-acrylate(PUA) emulsion containing fluorine and silicon in the core was synthesized by “one-pot” emulsion polymerization in the presence of castor oil-based polyurethane without traditional emulsifier, using methyl methacrylate (MMA), butyl acrylate (BA) as the main monomers, dodecafluoroheptyl methacrylate (G04), γ-methacryloxy propyl trimethoxyl silane (KH-570) as the functional monomers. The structure and properties of the fluorinated-silicated PUA and their films were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectrum (FT-IR) and contact angle testing. The results showed that fluorine and silicon monomers had effectively copolymerized with acrylic monomers and a core-shell structure in the latex was formed. The water contact angle for film-air interface is 92.5o, and the cetane contact angle for film-air interface is 47.5 o.

Novel acrylic resin denture base with enhanced mechanical properties by the incorporation of PMMA-modified hydroxyapatite

A kind of novel acrylic resin denture base enhanced by PMMA-modified hydroxyapatite (M-HAP) was prepared and the modification effect of HAP on the mechanical properties of denture base material was investigated in the present study. HAP whiskers were prepared by hydrothermal homogeneous precipitation process and were silanized by the coupling agent, 3-methacryloxy propyl trimethoxyl silane (γ-MPS), to induce the vinyl groups onto its surface. Methyl methacrylate (MMA) were then modified outside the vinyl functionalized HAP via polymerization to build a similar chemical structure with the acrylic matrix. A novel acrylic resin denture base was obtained through self-curing process with the incorporation of this PMMA-modified HAP, and the content of which ranged from 0wt% to 0.8wt%. Thermal gravimetric analysis (TGA), fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and universal testing apparatus were used to characterize M-HAP and corresponding denture base. The results showed that PMMA were successfully grafted onto the surface of HAP whiskers with up to 15wt% and the modification turned out to be useful for the dispersion and compatibility of whiskers in the acrylic resin matrix. The mechanical properties of the prepared denture base samples were enhanced greatly after incorporating with M-HAP fillers. The optimal incorporated content of M-HAP was also investigated.

Well-defined inorganic/organic nanocomposite by nano silica core-poly(methyl methacrylate/butylacrylate/trifluoroethyl methacrylate) shell

The novel inorganic/organic core–shell SiO2/P(MMA/BA/3FMA) nanocomposite for coating application is synthesized in this paper by seed emulsion polymerization, in which the inorganic phase is composed of nano-SiO2 modified by vinyl-trimethoxysilane (VMS) or γ-methacryloxy propyl trimethoxylsilane (MPMS), and the organic phase is made of terpolymer by 2,2,2-trifluoroethyl methacrylate (3FMA), methyl methacrylate (MMA), and n-butyl acrylate (BA). The chemical structure of SiO2/P(MMA/BA/3FMA) is characterized by FTIR. The effect of surfactant polyvinylpyrrolidone (PVP), sodium dodecyl sulfate (SDS)/octyl phenyl polyoxyethylene ether (TX-10), sodium dodecyl benzene sulfonate (SDBS)/TX-10 and sodium hexametaphosphate (SHMP) on the grafting ratio (GR) of VMS and MPMS, the dispersion of nano-SiO2 particles and the film properties of SiO2/P(MMA/BA/3FMA) are investigated by TGA, DLS, TEM, SEM, and XPS. The morphology variation and the particle size distributions of SiO2/P(MMA/BA/3FMA) with the content of surfactant and P(MMA/BA/3FMA) are characterized. It is found that MPMS is more effective than VMS in improving GR and the dispersion of nano-SiO2 particles. The surfactants are favor of gaining the higher GR in the multilayer grafted nano-SiO2, especially SDS/TX-10 for 17.6% GR. The morphology of SiO2/P(MMA/BA/3FMA) is controlled by the amount of SDS/TX-10 and P(MMA/BA/3FMA) as the core–shell particles, the stacked pomegranate seed with multicore and the multicore–single shell structure when w(MMA)/w(BA)/w(3FMA)=1.3/1/1. Among the different surfactants, SDBS/TX-10 and PVP could give the monodispersing nano-SiO2 in the terpolymer matrix of the films, but SDS/TX-10 and SDBS/TX-10 could perform the fluorine-rich surface.