MF Resin Research Articles

Pembuatan dan Karakteristik Resin Melamin Formaldehid sebagai Bahan Coating

This research aims to manufacture Melamine Formaldehyde Resin as a raw material coating with a mole ratio that is different and knowing the characteristics of MF resins . The research was carried out by reacting Melamine and Formaldehyde with a mole ratio of 1:2; 1:3; 1:4; 1:5 and 1:6 and characterize the properties of the resulting Melamine Formaldehyde Resin with Viscosity, Pot Life and pH parameter. The conclusión of this research that the best Melamine Formaldehyde Resin is produced on a mole ratio 1:6 of Melamine Formaldehyde with a reaction time of 14 minutes and the following characteristics : viscosity value is 1550 (mm 2 /s)/centistokes; Pot Life is 3 days and the pH is 6,63.

A Novel Elastic Urea–Melamine–Formaldehyde Foam: Structure and Properties

Melamine was chemically introduced into a urea–formaldehyde system via co-condensation reactions during curing and foaming process, and a novel elastic urea–melamine–formaldehyde (UMF) foam with improved thermal stability, insulation property, and flame retardancy was fabricated. It was found that with a decrease of the mass ratio of urea formaldehyde resin and melamine formaldehyde resin (UF/MF), the curing process of UMF was prolonged, and a high curing temperature was necessary. The UMF foam exhibited an interconnected network structure with increasing cell size and size distribution, higher open cell porosity, and lower apparent density compared with pure UF foam. Evident recoverable deformation can be observed for UMF foam during the compression testing, which was resulted from the elasticity and toughness. By addition of melamine, the thermal conductivity decreased, while the decomposition temperature, char yield, and LOI increased, and during burning, the expansion of the flame was suppressed. With increasing content of MF resin, the sound absorption coefficient increased at first and then declined.

Ratiometric Nanothermometer Based on Rhodamine Dye-Incorporated F127-Melamine-Formaldehyde Polymer Nanoparticle: Preparation, Characterization, Wide-Range Temperature Sensing, and Precise Intracellular Thermometry.

A series of fluorescent nanothermometers (FTs) was prepared with Rhodamine dye-incorporated Pluronic F-127-melamine-formaldehyde composite polymer nanoparticles (R-F127-MF NPs). The highly soluble Rhodamine dye molecules were bound with Pluronic F127 micelles and subsequently incorporated in the cross-linked MF resin NPs during high-temperature cross-link treatment. The morphology and chemical structure of R-F127-MF NPs were characterized with dynamic light scattering, electron microscopy, and Fourier-transform infrared (FTIR) spectra. Fluorescence properties and thermoresponsivities were analyzed using fluorescence spectra. R-F127-MF NPs are found to be monodispersed, presenting a size range of 88-105 nm, and have bright fluorescence and high stability in severe treatments such as autoclave sterilization and lyophilization. By simultaneously incorporating Rhodamine B and Rhodamine 110 (as reference) dyes at a doping ratio of 1:400 in the NPs, ratiometric FTs with a high sensibility of 7.6%·°C(-1) and a wide temperature sensing range from -20 to 110 °C were obtained. The FTs exhibit good stability in solutions with varied pH, ionic strengths, and viscosities and have similar working curves in both intracellular and extracellular environments. Cellular temperature variations in Hela cells during microwave exposure were successfully monitored using the FTs, indicating their considerable potential applications in the biomedical field.

High Pressure Laminates with Antimicrobial Properties.

High-pressure laminates (HPLs) are durable, resistant to environmental effects and good cost-benefit decorative surface composite materials with special properties tailored to meet market demand. In the present work, polyhexamethylene biguanide (PHMB) was incorporated for the first time into melamine-formaldehyde resin (MF) matrix on the outer layer of HPLs to provide them antimicrobial properties. Chemical binding of PHMB to resin matrix was detected on the surface of produced HPLs by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Antimicrobial evaluation tests were carried out on the ensuing HPLs doped with PHMB against gram-positive Listeria innocua and gram-negative Escherichia coli bacteria. The results revealed that laminates prepared with 1.0 wt % PHMB in MF resin were bacteriostatic (i.e., inhibited the growth of microorganisms), whereas those prepared with 2.4 wt % PHMB in MF resin exhibited bactericidal activity (i.e., inactivated the inoculated microorganisms). The results herein reported disclose a promising strategy for the production of HPLs with antimicrobial activity without affecting basic intrinsic quality parameters of composite material.

Melamine formaldehyde/polyvinyl alcohol composite fiber: Structures and properties controlled by reaction‐induced phase separation

ABSTRACTMelamine−formaldehyde resin (MF)/polyvinyl alcohol (PVA) composite fibers with different phase structures and properties were prepared through reaction induced phase separation by wet spinning. Raman spectroscopy, rotary viscometer, and miscibility index were used to characterize the MF resins with different reaction degrees (RD). The phase structures of composite spinning dopes and composite fibers were observed by optical microscope (OM) and scanning electron microscope (SEM). Mechanical properties, flame retardant properties, and thermal stability of the composite fibers were also tested. Results show that the composite fibers made from MF resins with different RD have different phase structures and properties; when the miscibility index (MI) of MF resin is 1.60, the obtained MF/PVA composite fiber shows a sea‐island phase structure, which endues the fiber with the best comprehensive properties: the breaking strength, breaking elongation, rupture work and limiting oxygen index (LOI) are 4.29 cN/dtex, 13.55%, 8.46 × 10−5 J/dtex and 43.1%, respectively. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42918.

Curing behavior of melamine-urea-formaldehyde (MUF) resin adhesive

In this work, MUF resin was tested by DMA method. It showed that G′ curves and strain curves together could be used to predict the curing behavior of MUF resins. The study showed that sequential formulation was preferred for the preparation of MUF resins. Hardener could accelerate the curing of MUF resins. But its addition amount should not be too high to affect the resins' shelf time. MUF showed medium thermal resistance when compared with UF and MF resins.

Effect of the surface modification of ammonium polyphosphate on the structure and property of melamine–formaldehyde resin microencapsulated ammonium polyphosphate and polypropylene flame retardant composites

Two kinds of ammonium polyphosphate (APP) including untreated APP and surface-modified APP treated by a silane coupling agent were microencapsulated by MF resin. Then PP/MCAPP flame-retardant material was prepared. The results indicated that the coating of MF microencapsulated surface-modified APP was more uniform and complete, and its thermal stability was higher than that of MF-microencapsulated untreated APP. Furthermore, the LOI value of PP/MCAPP (MF-microencapsulated surface-modified APP) composites was 30 and it could pass the UL-94 V-0 test; moreover, the water resistance of the composites was better than that of PP/MCAPP (MF-microencapsulated untreated APP).

Synthesis of 2-(4-aminophenyl)benzothiazoles using MF resin supported H+ under solvent free conditions

A simple and convenient approach to 2-(4-aminophenyl)benzothiazole derivatives by condensation of o-aminothiophenol with (un)substituted p-aminobenzoic acid under the action of melamine formaldehyde resin (MFR) supported sulfuric acid under microwave irradiation (MW) and solvent-free conditions has been developed. Structures of the corresponding products were elucidated by IR, 1H NMR spectra, and elemental analysis. The resin could be easily recovered and reused for subsequent reactions.

Fabrication of RDX, HMX and CL-20 based microcapsules via in situ polymerization of melamine–formaldehyde resins with reduced sensitivity

Melamine–formaldehyde resins (MF resins) were selected for the fabrication of three typical nitramine explosives (cyclotrimethylenetrinitramine, RDX; cyclotetramethylenetetranitramine, HMX; and hexanitrohexaazaisowurtzitane, CL-20) based microcapsules, the polymer coating shell could be prepared via a facile in situ polymerization of melamine and formaldehyde on the surface of explosive crystals. Structural characterizations and thermal properties of the core–shell composites were systematically studied by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), fourier-transform infrared (FT-IR) spectra and differential scanning calorimeter (DSC). The SEM and XPS results indicated that these three energetic cores were mostly well coated. XRD and FTIR analyses showed the combined characteristics of explosives and MF resins, and revealing that the polymorph of CL-20 maintained the optimal ε form during the whole preparing process. After coating, the endothermic polymorphic phase transition as well as the exothermic thermal decomposition temperature of the explosives was visibly increased, attributing to the outstanding heat resistance of MF resin shell. The impact sensitivity of the resultant microcapsules could be reduced from 2 to 3 times, depending on energetic material, after coating by 3wt% MF resins.

Synthesis and Characterization of Melamine-Formaldehyde Resin for Foaming Use

The effects of mole ratio of formaldehyde and melamine (F/M), solution pH, reaction temperature and time on the foaming melamine-formaldehyde resin (MF resin) with caprolactam as modifier were investigated by orthogonal experiment design where the solid content and the viscosity of the resin, the density and the size uniformity of the foam resin were used as performance evaluation parameters. The results had shown that the optimal conditions for preparing the foaming MF resin were F/M= 3.25, pH=8.0, T=90°C, t=45min. The MF resin prepared under the optimal conditions could be foamed well and its storage time was prolonged to 16 days. The structure and thermal properties of MF resin under the optimal conditions were investigated.

Drying and curing behaviour of melamine formaldehyde resin impregnated papers

ABSTRACTMelamine formaldehyde (MF) resins are widely used for the gluing and surface coating of wood‐based consumer products in the interior design of living environments. MF resins are especially relevant in decorative laminate applications because of their good performance‐to‐price ratio. In their industrial processing, an important intermediate state is the liquid MF prepolymer that is used for decorative paper impregnation. Here, the drying of impregnated papers is investigated with respect to premature curing. A new method to quantify water release upon drying that allows estimation of the degree of undesired precuring is described. Since curing proceeds via polycondensation, crosslinking brings about the release of water molecules. By thermogravimetric analysis (TGA), drying was studied in terms of water release due to physical drying (elimination of “dilution water”) and chemical crosslinking of the prepolymer to a three‐dimensional MF network (elimination of chemically liberated water). The results obtained by TGA/IR spectroscopic analysis of the liberated volatiles show that the emission of water from b‐stage MF can be clearly analytically separated into a physical (evaporation of dilution water) and a chemical (liberation via condensation) sequence. TGA experiments were correlated with curing experiments performed with differential scanning calorimetry (DSC) to estimate the residual crosslinking capacities of the impregnated papers. The drying conditions used during the preparation of impregnated decorative papers seemed to significantly affect their remaining reactivity only when harsh drying conditions were used. Upon heat exposure for prolonged time, precuring of the oligomer units results in a shift of the temperature maxima in TGA. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39860.

Flame Retardation of SBS Composites Containing Ammounium Polyphosphate and its Microcapsules

Flame retardant properties of ammonium polyphosphate (APP) and its two kinds of microcapsules, MFAPP with a shell of MF resin and EPAPP with a shell of epoxy resin, were studied in styrene-butadiene-styrene rubber (SBS). The results indicate that the microencapsulation of APP leads to an increase in LOI in SBS compared with APP. When dipentaerythritol is incorporated into the SBS composites containing APP microcapsules, a further improvement in flame retardancy of the composites is observed. Moreover, thermal decomposition behavior and mechanical properties of the SBS composites are investigated.

Pressure Sensitive Essence Microcapsules with MF-UF Resin as Double Wall

The paper studied the preparation and micro-encapsulation of pressure sensitive essence microcapsules with MF resin and UF resin as double wall by using the in situ polymerization method, and the optimal preparation conditions were also studied. The microcapsules were characterized on structure, morphologies, thermal properties, mean particle size and size distribution. The experiment illustrated that the wall of microcapsule consisted of the MF resin and the UF resin had been synthesized in the process of preparation, the essence oil was encapsulated into the microcapsules, the mean particle size and size distribution was well-proportioned and narrowed respectively, the particle morphologies were single core and global, the wall was hermetically sealed.

Synthesis and Properties of Microencapsulated Solid Paraffin Phase Change Materials

To prepare the phase change materials for efficient low-temperature latent heat storage, microcapsules with commercial solid paraffin were synthesized by using in-situ polymerization process. Liquid paraffin was used first as core materials since it facilitates the direct observation of containment by the shell of melamine-formaldehyde resin (MF resin), and examines easily the optimal synthesizing condition. The effects of emulsion processes, pre-polymerization conditions, shell material content and reaction time on the quality of microcapsules were investigated. The experimental investigations show that the optimal process of synthesizing liquid paraffin microcapsules is adoptable to that of solid paraffin microcapsules. The as-prepared solid paraffin microcapsules show high quality. The microcapsules surface was smooth and dense, and be free of any adhesion. The measurements show that in the microcapsules solid paraffin was well encapsulated by MF resin. The microcapsule size was almost within the range of 6~33 μm and most intense distribution at 23 μm. DSC measurements gave two endothermic peaks with initial phase change temperature at 35°C and 50°C respectively, and the total enthalpy was above 134 J/g.

Methylolation of melamine with incipient condensation. II. Mathematical modeling

AbstractA novel mathematical model is presented for the reaction between melamine (M) and formaldehyde (F) at pH = 9.0 and at temperatures between 38 and 90°C. It is based on a kinetic scheme that includes reversible methylolations, irreversible formation of (unsubstituted) methylene bridges, reversible formation of (unsubstituted) ether bridges, instantaneous dissolution of M, and instantaneous equilibrium for the hydration/dehydration of F. The model predicts the distributions of molecular weights and functionalities of the evolving MF resin. Arrhenius expressions were adjusted for the seven kinetic constants on the basis of measurements reported in the first part of this series. Even though the final products contain thousands of different molecular species, 21 of them constitute more than 90% of the total weights. During the initial period with negligible condensation, the undissolved M distorts the distributions of molecular weights and functionalities; but the reversibility of methylolations corrects for such distortion prior to the effective start of condensation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The application of microcapsules of PCM in flame resistant non‐woven materials

PurposeThe use of organic phase change materials microcapsules (mPCM) has been gaining ground in technical textiles and clothing as a temperature regulating medium and hence a means of keeping the body at a comfortable temperature when wearing impermeable protective clothes. However, for such applications as fire fighter's protective clothes, the standards require that all the material composing the material be fire resistant. The purpose of this paper is to produce a lining containing fire resistant microcapsules of PCM without using flammable binders.Design/methodology/approachThis work tests other ways of fixing mPCM to the fibres with a lot less binder present. Washfastness is evaluated in SEM photographs and by weight. The thermal effect is evaluated in a prototype plate calorimeter.FindingsThis method is first tested for fixing mPCM but the non‐woven still does not pass the test according to the standard EN532. Microcapsules are alternatively fixed with MF resin, non‐flammable, and by applying flame retardant recipes it is possible for the samples to pass the test.Research limitations/implicationsSince the amount of flame retardant necessary for the mPCM to stand the test, and the resin to thermo fix it is very high, the material becomes unacceptably stiff.Originality/valueBased on a new approach where reactive microcapsules without any binder are used, it is possible to use a lot less flame retardant and resin, and the material is resistant to the standard EN532. In this standard the material has to resist washing and still be flame retardant.

Design of highly porous melamine-based networks through a bicontinuous microemulsion templating strategy

Designing low density polymeric porous materials with defined pore sizes (diameters in the 100 nm range) still remains a real synthesis challenge. Here, for the first time, we present a strategy by which bicontinuous microemulsions are used as templating agents for the in-situ aqueous polycondensation of organic resins (melamine formaldehyde, MF). The behaviour of surfactants with different head-groups in systems including oil and MF-containing aqueous phase is studied. While many surfactants are not compatible with aqueous MF precondensates, here we report a non-ionic surfactant either used solely or along with anionic surfactants which prove to be successful at keeping bicontinuous microemulsion systems homogeneous even during early stages of polymerisation. However, upon acid-catalysis it becomes clear that the pore structure of the organic material is largely controlled by the kinetics of phase separation due to the sol–gel process rather than by the thermodynamic equilibrium of the template (microemulsion). Indeed, despite numerous attempts, stabilising the microemulsion interface with zero curvature (bicontinuous) has remained problematic. Instead, we show a new behaviour for the MF resin whereby non-spherical MF morphologies (i.e. thread-like structures) can be obtained by specific interactions between the aqueous amino resin and the acid counterions.

Thermal removal of nitrogen species from wood waste containing urea formaldehyde and melamine formaldehyde resins

The removal of nitrogen from wood board waste through a low temperature pyrolysis (523–573 K) is investigated with two analytical methods. The kinetic study of the thermal behaviour of wood board and of its components (wood, UF and MF resins) shows the feasibility of removing thermally nitrogen from wood board waste. Indeed, the range of temperatures associated with the degradation of wood is different from the one obtained for the degradation of UF and MF resin. Isothermal conditions enable the determination of a kinetic model for degradation of wood board and of its components and demonstrate that the thermal behaviour of wood board is not the reflection of the sum of its components’ behaviour. FTIR analysis of gas products confirms the feasibility removing nitrogen thermally and enables the evaluation of the optimum treatment conditions (temperature/duration). Elementary analysis of the treated samples and study of their low heating value (LHV) enable to quantify the efficiency of the thermal treatment in terms of nitrogen removal and of energy recovery. Results show that around 70% of the initial nitrogen can be removed from the waste, and that the temperature of treatment (between 523 K and 573 K) does not influence the efficiency in terms of nitrogen removal. Nevertheless, the ratio Residual energy/Initial energy (between 76% and 90%) is improved with the lowest temperature of treatment.

Miscibility and Phase Morphology of MF/PVAc Hybrid Resins for Surface Bonding of Building Interior Materials

AbstractThe objective of this research was to investigate the miscibility behavior of melamine‐formaldehyde resin and poly(vinyl acetate) blends for use as adhesives for surface materials in order to reduce formaldehyde emission. The investigation was conducted using differential scanning calorimetry, Fourier transform infrared spectroscopy, 13C CP/MAS solid state NMR, scanning electron microscope, atomic force microscopy and wide‐angle X‐ray scattering. Blends of various MF resin/PVAc weight compositions, comprising 0, 30, 50, 70 and 100%, were prepared in order to determine and compare the effect of PVAc content. These blends displayed a single cure temperature over the entire range of compositions indicating that this blend system was miscible in the amorphous phase due to the formation of hydrogen bonding between the amine groups of the MF resin and the carbonyl groups of PVAc. On the surface of the cured blends, the homogeneous dispersion of the PVAc phase in the MF resin was evident as small spherical domains and the blends were confirmed to be well combined.magnified image

Effect of Bio‐Scavengers on the Curing Behavior and Bonding Properties of Melamine‐Formaldehyde Resins

AbstractSummary: The effects of bio‐scavengers on the formaldehyde emission, bonding strength, curing behavior, and thermal decomposition properties of MF resins for engineered flooring and adhesion for wood were investigated. Four varieties of bio‐scavengers, tannin powder, wheat flour, rice husk flour, and charcoal, were added to MF resin at 5 wt.‐%. To determine formaldehyde emission and bonding strength, we manufactured engineered floorings. MF‐charcoal was most effective in reducing formaldehyde emission because of its porous nature, but its bonding strength was decreased. Tannin powder and wheat flour, which contain more hydroxyl groups, showed higher bonding strength and curing degree than pure MF resin did. Although the hydroxyl groups of the bio‐scavengers were effective in reducing formaldehyde emission and improve bonding strength and curing degree, rice husk flour and charcoal behaved like inorganic substances, thereby disturbing the adhesion between MF resin and wood and thus reducing the bonding strength. In thermogravimetric analysis, MF‐tannin showed the highest thermal stability in the low‐temperature range from 100 to 300 °C.Storage modulus (E′) of MF resin with various bio‐scavengers at a heating rate of 10 °C · min−1.magnified imageStorage modulus (E′) of MF resin with various bio‐scavengers at a heating rate of 10 °C · min−1.