Phenyl Silicone Resin Research Articles

A novel epoxy-functionalized hyperbranched polysiloxane (HPSi) endowing methyl phenyl silicone resin (Si603)/epoxy systems with enhanced compatibility and fire retardancy performance

A novel hyperbranched polysiloxane (HPSi) with a great amount of epoxy groups was synthesized as a compatibilizer of epoxy resin (EP)/methyl phenyl silicone resin (Si603) blends.

The investigation of methyl phenyl silicone resin/epoxy resin using epoxy-polysiloxane as compatibilizer

A novel polysiloxane (HPS) with epoxy and phenyl groups was synthesized by controlled hydrolysis and condensation of γ-(2,3-epoxypropoxy)propytrimethoxysilane (KH560) and diphenyl silanediol. Besides, HPS was used as the compatibilizer of the miscible diglycidyl ether of bisphenol A (DGEBA)/methyl phenyl silicone resin (Si603) blend. The structure and effect of HPS were characterized by Fourier transform infrared spectra, nuclear magnetic resonance (1H-NMR), differential scanning calorimetry, and scanning electron microscopy (SEM). The results showed that HPS could significantly improve the compatibility between epoxy resin (EP) and Si603 resin. In addition, the glass transition temperature (T g) of the blend increases with increasing amount of Si603 from 129 to 151 °C. The thermal stability of blending system was studied by thermogravimetric analysis, derivative thermogravimetric analysis and SEM. The results showed that the incorporation of Si603 into DGEBA resin not only obviously increased the thermal resistance, but also remarkably improved the flame retardancy. The high limiting oxygen index of the HPS/EP/Si603/DDM system at 31 is considered as excellent flame retardancy in the epoxy system.

Synergistic effect of methyl phenyl silicone resin and DOPO on the flame retardancy of epoxy resins

A series of flame-retarded epoxy resins (EPN) loaded with methyl phenyl silicone resin (Si603) and DOPO (9, 10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) have been prepared. The morphology of these EPN composites were characterized by differential scanning calorimentry (DSC). The mixed epoxy systems all exhibit single glass transition temperature which indicates a homogeneous morphology of these mixed epoxy systems. The thermal stability and flammability of these EPN composites were investigated with limiting oxygen index, UL 94 vertical burning, and themogravimetric analysis tests (TG). The results showed that the DOPO and Si603 system had excellent flame retardancy and antidripping properties for EPN. The TG curves suggested that there was a distinct synergistic effect of DOPO and Si603, and this effect greatly promoted the char formation of the EPN composites and hence improved the flame retardancy. Additionally, the structure and morphology of char residues were studied with Fourier transform infrared and scanning electron microscopy.

Enhanced Fluorescence, Morphological and Thermal Properties of CdSe/ZnS Quantum Dots Incorporated in Silicone Resin

Our research focused on the morphological and optical properties of core/shell cadmium selenide/zinc sulfide (CdSe/ZnS) quantum dots incorporated in silicone resin. After dispersing ligand-coated quantum dots into Dow Corning two-component silicone resins (OE6630A and OE6630B at 1:4 mixing ratio by weight), the resins were cured at 150 degrees C for 1.5 hours to produce the quantum dot-silicone resin nanocomposites. The optical, morphological and thermal properties of the quantum dot incorporated in silicone resin were investigated by ultraviolet-visible, fluorescence, atomic force microscopy, field emission scanning electron microscopy, differential scanning calorimetry and thermogravimetric analysis. When the quantum dots, originally coated with trioctylamine ligand, were transferred from a chloroform solvent to methyl phenyl silicone oil and silicone resins of high viscosity, the quantum dots showed increased turbidity and lowered fluorescence intensity. Fluorescence enhancement was investigated by using various functional ligands such as poly(1, 1-dimethyl silazane) (multi-silazane), hexamethylenediamine (diamine), cysteamine (amino-thiol), triethylsilane (reactive hydrosilane), hexamethyldisilazane, nonamethyltrisilazane, octamethylcyclotetrasilazane (reactive amines). The results showed that the reactive amines were good additive ligands for enhancing the fluorescence of CdSe/ZnS quantum dots dispersed in the silicone resins, providing 1.2-2.48 Im/W and 4.2-5.56% higher luminous efficiency and photoluminescence conversion efficiency, respectively. We speculate that these reactive amines donate electrons to the surface electron traps, thereby reducing charge recombination. In addition, quantum dots aggregate to form quantum dot clusters with a relatively homogeneously dispersed in the silicone resin matrices, showing good emission properties due to surface passivation and good colloidal stability with the addition of silazane compounds to the resin. Furthermore, the addition of silazane compounds to quantum dots-silicone resin system also shows the improved thermal stability of the as-synthesized nanocomposites.

Morphology and properties of TGDDM/DDS epoxy systems toughened by amino-bearing phenyl silicone resins

A series of amino-bearing phenyl silicone resins (APSR) were synthesized for toughening the tetraglycidyl 4,4′-diaminodiphenyl-methane (TGDDM) epoxy resin cured with 4,4′-diamino diphenyl sulfone. The microstructure of the TGDDM/APSR resins was highly dependent on the amino content of APSR and the loading level of the modifier. Based on the SEM and TEM studies, microstructure evolution of the TGDDM/APSR resins in the curing process was imaged. The toughness of the TGDDM resin was effectively improved without sacrificing the tensile strength, the flexural strength, and the modulus. The thermal stability and water resistance were improved as well. However, the modifier brought in a noticeable lowering in the glass transition temperature.

Preparation and properties of cyanate ester/polyorganosiloxane blends with lower dielectric loss and improved toughness

AbstractNovel modified cyanate ester resins (EPMPS‐n/BADCy), with significantly decreased dielectric loss and improved toughness, were developed by copolymerizing the cyanate ester resin, 2, 2′‐bis (4‐cyanatophenyl) isopropylidene resin) (BADCy), with an epoxidized methyl phenyl silicone resin (EPMPS). The curing behavior of EPMPS‐n/BADCy and the typical properties of the corresponding cured EPMPS‐n/BADCy were systematically investigated. The results show that the addition of EPMPS into BADCy can not only accelerate the curing reaction of BADCy, but also decrease dielectric loss and enhance the impact strength as well as water resistance. For example, in the case of the modified BADCy resin with 15 wt%EPMPS, its impact strength is 17.8 kJ/m2, about 3 times of that of pure BADCy resin and its water absorption is only 0.25%, about one‐half of that of pure BADCy resin. In addition, while the dielectric loss is only 79% of that of pure BADCy resin, while its dielectric constant remains constant over the frequency range of 1KHz‐1 MHz. The above results suggest that EPMPS‐n/BADCy have great potential to be used as the matrix or adhesive for advanced composites. Copyright © 2009 John Wiley & Sons, Ltd.

Preparation and characterisation of phenyl silicone‐acrylic polyol coatings

Purpose – The paper's aim is to investigate improvement of strength and adhesion of silicone‐acrylic hybrid systems.Design/methodology/approach – The presence of Si‐C bonds in phenyl silicone should be able to improve strength, adhesion and thermal properties of phenyl silicone‐acrylic polyol coating. Different weight ratios of phenyl silicone and acrylic polyol resins were blended in order to obtain the composition for optimum strength, adhesion and thermal properties. Strength was evaluated using an impact resistance tester. Coating adhesion was studied by measuring the contact angle and performing cross hatch cutting. The thermal properties were studied using differential scanning calorimetry.Findings – Blending phenyl silicone intermediate resin with acrylic polyol resin showed significant improvement in strength and adhesion properties compared to pure acrylic polyol resin. This paper shows that the composition of such coatings influences the glass transition temperature (Tg), which in turn affects t...

Synthesis and Characterization of a Silicone Resin with Silphenylene Units in Si–O–Si Backbones II

A silicone resin with silphenylene units in Si—O—Si backbones was prepared through hydrolysis-polycondensation of self-synthesized 1,4-bis(diethoxymethylsilyl)benzene (BDSB) and other alkoxysilanes. The structure and properties of this novel silicone resin were characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR), thermogravimetric analysis (TG), scanning electron microscope (SEM) and electrochemical impedance spectrum (EIS). The results of GPC, IR and NMR showed that silphenylene units had been successfully incorporated into the backbones of silicone resin. TG analyses reveal that silicone resin with silphenylene units in its backbones had a higher heat resistance than the usual methyl phenyl silicone resin. SEM results demonstrated that this silicone resin could form a full and uniform film, and its clear paints were able to stand temperatures below 350 °C. EIS analysis revealed that clear paints of this silicone resin have good resistance to corrosion.