Phenoxy Resin Research Articles

Composite organic encapsulate film with epoxy and benzoxazine

Electronic devices based on organic materials readily degrade owing to moisture or oxygen. Encapsulation materials and films made of inorganic and organic materials have been studied to arrest degradation, and polymeric materials have become more desirable owing to their flexibility, transparency, and processability. In this study, polymeric composite films that are fabricated under atmospheric conditions are studied. The composite encapsulation films consist of a combination of bisphenol A phenoxy resin and epoxy resin (POL) and synthesized benzoxazine monomer (eugenol-based Eu-Bzo (EZ), bisphenol-S based BPS-SA-Bzo (PZ), and bisphenol-AF based BPAF-SA-Bzo (FZ)). The composite with benzoxazine exhibits superior barrier characteristics with a highly hydrophobic nature compared to POL. The composite film with 3% Eu-Bzo exhibits lower moisture permeation rate of 2.02 g m−2 d−1 with 90% transparency in comparison to POL (3.65 g m−2 d−1) and PET (4.25 g m−2 d−1). The novel composition of epoxy and phenoxy resins along with benzoxazine is a potential candidate for fabricating barrier materials for flexible printed organic electronics.

Synthesis of 2-Amino-5-Carboxamide Thiazole Derivatives via Dehydrative Cyclization of Thiourea Intermediate Resin on Solid Phase.

In this study, we synthesized 2-amino-5-carboxamide thiazole derivatives on solid phase. The synthesis of the library starts with the reductive amination of the 4-formyl-3-methoxy phenoxy resin to prevent isomer formation. The dehydrative cyclization of thiourea intermediate resin, which is the key step in the synthetic process, was successfully synthesized using α-bromoketone in the presence of the DMF so as to afford 2-amino-5-carboxylate thiazole resin. The resulting resin is coupled with various amines. Finally, the 2-amino-5-carboxamide thiazole resin was cleaved from the polymer support using a TFA and DCM cocktail. The physicochemical properties of the proposed 2-amino-5-carboxamide thiazole derivatives were calculated and showed potential to be an reasonable oral bioavailability drug properties as determined by Lipinski's Rule.

Heat Durability and Curing Behavior of Phenoxy Resin by Epoxy Resin Doping with Post-crosslinking by Thermal Treatment

Heat Durability and Curing Behavior of Phenoxy Resin by Epoxy Resin Doping with Post-crosslinking by Thermal Treatment

Effect of hydrogen bonding on the physicochemical and rheological features of chemically modified phenoxy

Selective reduction of hydrogen bonds of a phenoxy resin gave samples particularly suitable to investigate specific interactions in associative polymers. The glass transition temperature decreased when reducing hydrogen bonds, but dielectric results indicated that α and β relaxations are rather affected by steric hindrances (bulky groups). A model accounting for the combined effect of entanglements and secondary interactions on viscosity, which can be generalised for other associative polymers, is proposed and hydrogen bonds/entanglements rate is determined. Dynamic viscoelastic results at T = 170 °C and T - Tg = 80 °C, showed that hydrogen bonds did not constitute a network and were weakened by temperature. The non-linear viscoelastic parameter Q0 decreased as the amount of hydrogen bonds was reduced. LAOS (Large Amplitude Oscillatory Shear) experiments constitute a new rheological tool to investigate associative polymers. Strain hardening in extensional flow was probed to be a consequence of the long relaxation times associated to hydrogen bonds and obtained from viscoelastic data.

High barrier performance of the multilayer film based on epoxy and montmorillonite

A flexible organic device needs a protective encapsulating layer to resist degradation of the device due to environmental oxygen and moisture. The performance of organic devices degrades with time due to a self-process of delamination and oxide formation of the cathode by environmental oxygen and moisture for electrochemical processes. Here, a flexible multilayer barrier film, which is a sandwiched composite layer with organic layers, has been fabricated in an inexpensive way under atmospheric conditions using an applicator on PET substrate. An organic layer (POL) consists of bisphenol A-type phenoxy resin and epoxy resin. For the middle composite layer (MMT), a composite with montmorillonite has been used as an interactive barrier. The multilayer film with ball-milled montmorillonite 2% composite layer shows lower moisture permeation rate of 2.850 × 10−2 gm−2day-1 than only POL on PET substrate. Fabrication of flexible multilayer barrier film from solution has promising industrial prospects due to facile processing at low temperatures.

Vanillin‐based polymers: IV. Hydrovanilloin epoxy resins

ABSTRACTIn this study, hydrovanilloin synthesized by electrochemical dimerization of vanillin has been used as a renewable substitute for bisphenol A for the preparation of epoxy resins. The reaction of the disodium salt of hydrovanilloin:epichlorohydrin 1:2 mol ratio at 80°C for 30 min in water gave a hydrovanilloin – diglycidyl ether phenoxy resin. This hard thermoplastic resin showed Tg of 135°C and stable up to 255°C in air. On the other hand, the disodium salt of hydrovanilloin:epichlorohydrin 1:4 mol ratio at 80°C for 30 min in water gives a curable oligomer of hydrovanilloin – diglycidyl ether with 2.1 repeating units. This oligomer could be cured with aliphatic diamines: 1,2‐diaminoethane, 1,4‐diaminobutane, 1,6‐diaminohexane, and isophorone diamine to give hard epoxy resins with Tg values of 116, 118, 149 and 146°C, respectively. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47000.

Versatile Epoxy/Phenoxy/Anhydride-Based Hybrid Adhesive Films for Deoxidization and Electrical Interconnection

We manufactured a hybrid adhesive film capable of curable deoxidization by combining thermoplastics and thermosets. The generated acidic moieties on this hybrid adhesive film completely removed the oxide layer of various Sn-based metal solders and Cu, leading to electrical interconnection. The chemical structure, reaction rate, and glass transition temperature (Tg) of the films were examined via Fourier transform infrared spectroscopy and differential scanning calorimetry. The initial reaction rate of the hybrid deoxidizing adhesive films increased with increasing concentration of anhydride and phenoxy resin. Meanwhile, the reaction rate at the end for curing completion decreased as a function of anhydride and phenoxy resin. Tg of the films decreased with the increase in anhydride and phenoxy resin concentrations. The fabricated film resulted in complete wetting of the solder/Cu for electrical interconnection between semiconductor chips as a promising electronic application. This hybrid film can be useful...

Two-step pre-processing enrichment of waste printed circuit boards: Mechanical milling and physical separation

Abstract Printed circuit boards (PCBs), one of the most complex components of e-waste, contain different metallic and non-metallic components. Recycling of waste PCBs is an important issue, from both aspects of hazardous waste management and recovery of valuable materials. In this study, for the first time, a mechanical-physical separation method for recovery of metallic elements of waste PCBs without any chemical or/and thermal processes was introduced. Two milling stages were applied to enhance the liberation degree, followed by a physical flotation process for enrichment. Based on the elemental analysis, the total metal concentration increased by 75% after the second milling in coarser particle size classifications and ceramic components has decreased significantly. Phase identification techniques confirmed that the ceramic portion is mainly CaO+SiO2+Al2O3, which generally exist inside the boards as glass fibres. Using Fourier transform infrared spectroscopy (FTIR) spectra 3 nominees of phenoxy resin, poly vinyl acetate and vinyl chloride were suggested as the major polymer content of the crushed waste PCBs. Scanning electron microscopy (SEM) demonstrated higher degree of liberation in the higher meshes for metallic and non-metallic components but it was lower for fibre glasses. The thermal pyrolysis using infrared gas analyser proved that the most volatile substances are not simple greenhouse gases such as CO, CO2 and CH4. Eventually, beneficiation using bromoform + acetone resulted in two phases of high density (sunk) and low density (float), in which the former one was enriched in metals excluding Al and Sn, and the latter one was almost depleted from metals.

Effect of voids and degree of polymerization of matrix on tensile strength properties of continuous fiber reinforced composite materials with in-situ polymerizable phenoxy resin

Effect of voids and degree of polymerization of matrix on tensile strength properties of continuous fiber reinforced composite materials with in-situ polymerizable phenoxy resin

Enhancing the Compatibility of Poly (1,4-butylene adipate) and Phenoxy Resin in Blends.

This work concerns the enhancement in the compatibility of blends of poly (1,4-butylene adipate) (PBA) with poly (hydroxy ether of bisphenol-A) (phenoxy) via alcoholytic exchange. Results on the thermal behavior and morphology show that the blended PBA/phenoxy system exhibits a homogeneous phase and a composition-dependent glass transition temperature (Tg). The interaction parameter (χ12) of PBA/phenoxy blends was calculated using the melting point depression method and was found to be −0.336. However, the compatibilization of PBA/phenoxy blends can be enhanced by chemical exchange reactions between PBA and phenoxy upon annealing. Annealed PBA/phenoxy blends were found to have a homogeneous phase with a higher Tg than that of the blended samples, and a smooth surface topography that could be improved by annealing at high temperature. The results of this investigation demonstrate that promotional phase compatibilization in the PBA/phenoxy blend can only be obtained upon thermal annealing, thus causing transreactions to occur between the dangling –OH of the phenoxy and the ester functional groups in PBA. Extensive transreactions cause alcoholytic exchange between the PBA and phenoxy to form a network, thus reducing the mobility of the polymer chain. Finally, the crystallinity of PBA decreased as the degree of transreaction in the blends increased.

Phase Behavior and Its Effects on Crystallization in a Poly(trimethylene terephthalate)/Phenoxy Resin Blend.

Phase behavior and its effects on crystallization in an extruded poly(trimethylene terephthalate) (PTT)/phenoxy resin blend were studied with time-resolved light scattering (TRLS), optical microscopy (OM), differential scanning calorimetry (DSC), and small-angle X-ray scattering (SAXS). During annealing in the molten state, a two-phase structure with unique periodicity and phase connectivity was developed by liquid–liquid phase separation. After the formation of the phase-separated structure, the blend was homogenized by the interchange reactions between the two polymers. The crystallization behavior of PTT predominantly depended on the phase morphology developed during annealing. The pre-existing phase structures disturbed the lamellar orientation, resulting in a poorly ordered spherulitic superstructure.

炭素繊維強化フェノキシ樹脂複合材料の加熱プレス成形と力学的特性評価

炭素繊維強化フェノキシ樹脂複合材料の加熱プレス成形と力学的特性評価

柔軟性フェノキシ樹脂配合によるシアネートエステル樹脂系高熱伝導複合材料の接着性向上

パワーモジュールにおいては，セラミックス材料に代わり低コストの樹脂複合材料を絶縁基板に用いる検討が進んでいる。樹脂複合材料を絶縁基板に用いるためには，高放熱性に加え，高耐熱性や銅など金属との接着性が求められる。本研究では，窒化ホウ素(h-BN)粒子を62 vol%と高充填して高い熱伝導率を有する複合材料において，耐熱性と接着性の向上を試みた。複合材料のベース樹脂に耐熱性の高いシアネートエステル樹脂を用い，柔軟性に富む可とう性フェノキシ樹脂を配合した。その結果，19 W/(m・K)の高い放熱性を確保しながら，耐熱性が高く，銅との接着ピール強度が8.0 N/cmと高い接着性を有する複合材料を得ることができた。

Occurrence and Distribution of Microplastics in the Sea Surface Microlayer in Jinhae Bay, South Korea.

Microplastic contamination of the marine environment is a worldwide concern. The abundance of microplastics was evaluated in the sea surface microlayer in Jinhae Bay, on the southern coast of Korea. The microplastics in this study are divided into paint resin particles and plastics by polymer type. The mean abundance of paint resin particles (94 ± 68 particles/L) was comparable to that of plastics (88 ± 68 particles/L). Fragmented microplastics, including paint resin particles, accounted for 75 % of total particles, followed by spherules (14 %), fibers (5.8 %), expanded polystyrene (4.6 %), and sheets (1.6 %). Alkyd (35 %) and poly(acrylate/styrene) (16 %) derived from ship paint resin were dominant, and the other microplastic samples consisted of polypropylene, polyethylene, phenoxy resin, polystyrene, polyester, synthetic rubber, and other polymers. The abundance of plastics was significantly (p < 0.05) higher in Jinhae Bay, which is surrounded by a coastal city, than along the east coast of Geoje, which is relatively open sea. The floating microplastic abundance in surface water was the highest reported worldwide.

Static and dynamic percolation of phenoxy/carbon nanotube nanocomposites

The electrical conductivity of a carbon nanotube/phenoxy nanocomposite fabricated by melt-processing is presented. A low percolation threshold (pc∼0.20wt.%) for carbon nanotubes in phenoxy, a thermoplastic epoxy, is reported. The dispersion of the nanofillers within phenoxy matrix was examined by scanning electron microscopy, showing good levels of dispersion without aggregates. The temperature dependence of nanotube network formation is described and explained by a dynamic percolation process. Suitable processing and annealing conditions are provided to achieve low percolation thresholds based on observed electrical and rheological results. Since these phenoxy resins are dissolvable into epoxy, these findings open up possibilities to deliver carbon nanotubes into composites based on such epoxy resin, creating hierarchical nanoengineered composites.

Surface roughening of PET films through blend phase coarsening.

In this study, a novel method to increase the surface roughness of polyethylene terephthalate (PET) films is proposed. The mechanism of phase coarsening at the surface in extruded thin films of PET blended with low concentrations of polystyrene (PS) was investigated. A small amount of poly(hyroxyl ether) of bisphenol A (phenoxy resin, PKHH) was found to significantly increase the surface roughness due to its effect on the PS-PET interfacial tension. X-ray photoelectron spectroscopy (XPS) results indicated that in the presence of PKHH, PS droplets migrated spontaneously towards the surface of the polymer film. An increased local concentration of PS near the surface took the form of encapsulated droplets. Above the flow temperature of the blend, the local concentration of PS eventually reached a level where a co-continuous morphology occurred, resulting in the instabilities on the surface of the film. The adhesion properties of films with various roughnesses were determined using a pull-off test and found to be significantly increased, which suggested that co-continuous morphology and the coarsening process increased the adhesive properties of the film.

Low-molecular-weight thermoplastic modifiers as effective healing agents in mendable epoxy networks

Solid-state healing of epoxy networks is shown to be an effective and robust mechanism for highly cross-linked epoxy networks. Using diglycidyl ether of bisphenol A epoxy resin and diethyltoluenediamine, the cured epoxy network is transformed into a mendable system using phenoxy resin and low-molecular-weight polybisphenol A-co-epichlorohydrin) thermoplastic modifiers. Using functionally terminated low-molecular-weight poly(bisphenol A-co-epichlorohydrina) thermoplastic modifiers as healing agents reveals that salicylic acid or neutralized sodium salicylate groups produce healing similar to high-molecular-weight non-functional phenoxy resin as measured using single-end notched beam testing. The miscibility of both thermoplastics in the diglycidyl ether of bisphenol A/diethyltoluenediamine system was evaluated using differential scanning calorimetry and dynamic mechanical thermal analysis and identified as being important to promoting healing. Near-infrared spectroscopy showed that the network structure was unaffected by the thermoplastic modification, suggesting that healing occurred primarily through physical or non-covalent mechanisms rather than covalent bonding. The potential for self-assembly of the salicylic acid and neutralized sodium salicylate groups to form a high-molecular-weight thermoplastic in situ was also discussed as being a possible reason for the improved level of healing with the low-molecular-weight thermoplastic.

Thermal decomposition of phenoxy/clay nanocomposites: Effect of organoclay microstructure

The influence of organoclays on the thermal decomposition pathway of poly(hydroxyl ether of bisphenol A) (Ph) was analysed under nitrogen and air. In the two clays employed, montmorillonite and vermiculite, the organic clay modifier, a polar alkylammonium surfactant, led to different interlayer arrangements. Nanocomposite formation was established by X-ray diffraction and transmission electron microscopy. Thermal degradation of phenoxy and its nanocomposites was analysed by thermogravimetry (TGA/DTGA) and the evolved gases were investigated using thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TGA/FTIR). In both inert and oxidative atmosphere, it was observed that for the same organoclay proportion, nanocomposites containing organo-modified montmorillonite (Cloisite 30B) decompose at higher temperatures than those containing organo-modified vermiculite (VMT-ETO). This behaviour was attributed to the presence of the original metallic cations as a consequence of the incomplete exchange obtained in the organic modification of vermiculite. FTIR spectra of the evolved gases demonstrated that the incorporation of organoclays into phenoxy resin does not modify the degradation pathway of phenoxy, although the decomposition of the matrix is accelerated, possibly as a consequence of acidic sites created in organical decomposition.

Assessment of intertube interactions in different functionalized multiwalled carbon nanotubes incorporated in a phenoxy resin

AbstractIn this work, about 1 wt% of different functionalized carbon nanotubes (CNTs), namely CNTCOOH (CNT with carboxylic groups), CNTNH2 (CNT with amine groups) and CNTOH (CNT with hydroxyl groups), as well as nonfunctionalized CNTs were incorporated into a phenoxy resin via a melt mixing process. The extent of intertubes and polymer–tubes interactions and their influence on state of CNTs dispersion were assessed through determination of electrical, rheological, and morphological characteristics. CNTNH2 showed the lowest intertubes interactions followed by CNTOH and CNTCOOH. Nanocomposite made from CNTCOOH showed the poorest state of CNTs dispersion and the biggest CNTs agglomerates and it remained nonconductive. The acid‐functionalized CNTs were not able to form strong polymer–tube interactions because of their high cohesive energy and therefore in the melt rheological investigations they exhibited the lowest storage modulus and complex viscosity as well as the highest loss factor among all the studied CNTs. A good balance between intertubes and polymer–tube interactions is necessary through proper selection of CNTs functional groups for achieving a good state of CNTs dispersion and consequently obtaining enhanced electrical and viscoelastic properties. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

Photooxidation of polymers: Relating material properties to chemical changes

This paper is devoted to a comprehensive study of the photo-oxidation of polymeric materials with the goal of correlating modifications of the polymer properties at the molecular and macroscopic levels. Several techniques were used to characterise the modifications of the chemical properties and mechanical behaviour over time under UV light. The methodology was developed on materials used as organic coatings; initially, a well-characterised phenoxy resin (PKHJ ®) was chosen as a model and then the approach was applied to an acrylate-melamine thermoset currently used as a topcoat in the automotive industry. Analysis of degraded samples by IR spectroscopy allowed us to propose a photo-oxidation mechanism. This mechanism suggested that chain scission occurred under photo-oxidation. To entirely understand the degradation of the polymers, gel fraction, thermoporosimetry, DMA, AFM nanoindentation and micro-hardness determinations were performed. The results showed that crosslinking reactions occurred in competition with chain scission and explained for the first time why crosslinking reactions were quite prevalent. Based on the obtained results, quantitative correlations were made between the various criteria of degradation, thus relating the chemical structure changes to the mechanical property modifications.