Dimethyloldihydroxyethylene Urea Research Articles

Achieving sustainable and highly efficient wood bonding through synergistic plant root-driven penetration mode with a hyperactive interface

Wood adhesives are widely used in furniture manufacturing, the construction industry, and the fabrication of the internal components of aircraft, cars, and sports equipment. Therefore, the development of wooden adhesives with high stability, strength, and efficiency is a vital research area. Although most studies have focused on improving the bonding properties of adhesives, achieving direct interface control from wood remains a challenge. This study was designed based on the plant root-driven adhesion method to create a hyperactive-interface self-driven regulated wood capable of spreading adhesive into the wood and inducing crosslinking to improve adhesive strength. A multi-poly silicate network structure with multiple reactive sites was formed through the self-polymerization of sodium silicate and crosslinking with dimethylol dihydroxy ethylene urea (DMDHEU) to achieve densified wood and improve the reactivity of the wood surface and interior. Consequently, the environmentally friendly polyvinyl acetate (PVAc) underwent a self-driven bonding process with the wood. These findings indicate that PVAc penetrated the interior of the wood, disrupting the combination of sodium silicate and DMDHEU and grafting onto the reactive sites. This process resulted in a tightly bonded interface connection. Consequently, the shear strength increased from 4.4 to 5.5 MPa, and the wood breaking rate increased from 21.00 % to 45.80 %, representing a 25 % and 118.10 % increase, respectively. Moreover, the tensile strength of the wood in longitudinal joints, transverse joints, miter joints, and mortise–tenon joints was assessed. The results revealed that the sodium silicate/DMDHEU-regulated wood (SS/DDRW) exhibited significantly higher adhesive strength than the original wood (OW). Hence, this bionic design represents a simple and efficient strategy for developing wood adhesives.

Building bridging structures and crystallization reinforcement in sodium silicate-modified poplar by dimethylol dihydroxyethylene urea

Building bridging structures and crystallization reinforcement in sodium silicate-modified poplar by dimethylol dihydroxyethylene urea

Intercellular Matrix Infiltration Improves the Wet Strength of Delignified Wood Composites.

Delignified wood (DW) represents a promising bio-based fibrous material as a reinforcing component in high-performance composites. These cellulose composites possess excellent strength and stiffness in the dry state, which are significantly higher than for natural wood. However, in the wet state, a penetrating water layer enters the intercellular regions and disrupts the stress transfer mechanisms between cell fibers in fully DW. This water layer initially facilitates complex shaping of the material but imparts DW composites with very low wet stiffness and strength. Therefore, a sufficient stress transfer in the wet state necessitates a resin impregnation of these intercellular regions, establishing bonding mechanisms between adjacent fibers. Here, we utilize a water-based dimethyloldihydroxyethylene urea thermosetting matrix (DMDHEU) and compare it with a non-water-based epoxy matrix. We infiltrate these resins into DW and investigate their spatial distribution by scanning electron microscopy, atomic force microscopy, and confocal Raman spectroscopy. The water-based resin impregnates the intercellular areas and generates an artificial compound middle lamella, while the epoxy infiltrates only the cell lumina of the dry DW. Tensile tests in the dry and wet states show that the DMDHEU matrix infiltration of the intercellular areas and the cell wall results in a higher tensile strength and stiffness compared to the epoxy resin. Here, the artificial compound middle lamella made of DMDHEU bonds adjacent fibers together and substantially increases the composites' wet strength. This study elucidates the importance of the interaction and spatial distribution of the resin system within the DW structure to improve mechanical properties, particularly in the wet state.

Physical and Mechanical Properties and Decay Resistance of Poplar Modified with mDMDHEU

Chemical modification as a non-biocidal treatment is an effective method to improve physical and biological properties of wood. Poplar is a fast growing species but has poor dimensional stability and durability in addition to low mechanical properties. Low molecular weight Dimethylol dihydroxyethyleneurea (mDMDHEU) was used to improve the properties of poplar mainly dimensional stability and decay resistance. Results indicated high anti-swelling efficiency (ASE), but low variation between both concentrations of mDMDHEU. Tangential swelling was greatly reduced by mDMDHEU treatment during the water immersion period. Untreated poplar samples were severely decayed as compared to modified samples. Modified samples showed lower bending strength unlike to compression strength. Ester peak at 1720 cm-1 revealed chemical reaction between chemical reagent and wood cell wall components. Control samples exhibited considerably higher thermal degradation when compared to the samples modified with mDMDHEU.

Multi response optimization in the development of anti-pilling and easy care finished rayon from bamboo and bamboo/cotton fabrics using desirability function

The present study discusses the optimization of process parameters of anti- pilling and resin finished rayon from 100% bamboo and 50:50 bamboo/ cotton fabrics used in home textile. Two weave structures, plain and five harness satin were selected. The optimization was carried out using desirability function a statistical technique for multiple response optimization. This was done by software called Design Expert 8.0.1. The five factors namely, Appretan® N 9211 as an anti-pilling agent (a non-ionic acrylate copolymer), Arkofix® NF as crease resistant agent (dimethylol dihydroxy ethylene urea, DMDHEU), fabric blend ratio, fabric weaves and curing method were analysed using 23 32 mixed level factorial design. The optimum conditions were explored for concentration of Appretan® N 9211, Arkofix® NF and curing methods. The process was evaluated with respect to pilling before and after wash, abrasion resistance, tensile, tear strength, Berger whiteness, yellowness index, dimensional stability, smoothness appearance and colour fastness to light. In order to generate the desirability values, the equal weightage was given to all response variables, but different importance was assigned based on the finish applied and industrial requirements. Four optimized recipes each for rayon from 100% bamboo and of 50:50 bamboo/cotton plain and satin weaves were suggested based on the high value of desirability.

Multifunctional finishing of cotton using zinc oxide and silicon dioxide nanoparticles along with DMDHEU

PurposeThis study aims at evaluating the properties of cotton fabric after nanofinishing using zinc oxide and silicon dioxide nanoparticles along with dimethylol dihydroxyethylene urea (DMDHEU).Design/methodology/approachDMDHEU recipes was optimized by Box-Behnken Design before using it with nanoparticles. These nanoparticles were synthesized by sol gel technique and applied to the fabric by pad-dry-cure method. The treated samples were evaluated for functional properties such as self-cleaning, antibacterial and ultraviolet (UV) protection properties.FindingsDue to the use of DMDHEU, crease recovery property was obtained. The results showed good antibacterial property against S-aureus (gram positive) bacteria and E-coli (gram negative). UV protection property of combined nano-finished samples showed good results, as they showed very low transmission of UV-irradiation when exposed to UV-rays compared to single nanoparticle finished samples. Self-cleaning property of finished cotton was found to be good even after five washing cycles.Originality/valueIn this study, nanofinishing of cotton fabric with zinc oxide and silicon dioxide nanoparticles along with DMDHEU was studied to achieve promising functional properties with long durability of nanofinishing not studied earlier.

Mechanical property study of plywood bonded with dimethylol dihydroxy ethylene urea crosslinked rice starch- natural rubber latex-based adhesive

There has been an increase in the demand for adhesives due to the increasing applications of plywood panels in the home furnishings and decorative items industries around the world. Most of the wood-based panels industry depends on synthetic adhesives due to its low cost and high performance. However, because synthetic adhesives emit the carcinogenic gas formaldehyde and increase the risk of human health, there is a growing interest in developing non-toxic and eco-friendly wood adhesives made from renewable materials. The present research aims to develop a bio-adhesive for plywood bonding based on two biopolymers: natural rubber latex (NRL) and dimethylol dihydroxy ethylene urea (DMDHEU) crosslinked rice starch. A bio-adhesive was ultimately formulated with varying weight ratio of NRL and DMDHEU crosslinked rice starch at 1:3, 1:1 and 3:1 respectively. Mechanical characteristics of plywood samples fabricated with the formulated bio-adhesive were measured using IS 17,304 and ISO 12466–1-2007 via hot press at 120 °C. The modulus of rupture (MOR) of plywood glued with Dm-B was 63 MPa, the modulus of elasticity (MOE) was 6480 MPa, and the internal bonding (IB) was 1.48 MPa, each of which met the ISO 12466–2-2007 and IS 303 standards. According to the findings, Dm-B had a profound impact on the performance of adhesion properties and contributed to the elimination of the use of hazardous synthetic adhesives.

Investigation into the effect of resin finish on the functional characteristics of plain fabrics using different curing methods

PurposeCellulosic fabric and plain weave are the most commonly used material in home textiles. The poor wrinkling, dimensional stability and pilling are some of the problems faced during usage. The textile industries apply resin finish to improve these characteristics. The purpose of this study is to improve pilling resistance, dimensional stability and smoothness appearance (SA) of rayon and rayon/cotton plain fabrics using different concentrations of dimethyloldihydroxyethylene urea (DMDHEU) and acrylic copolymer. The finish was fixed using two different fixation methods.Design/methodology/approachThree concentrations, 40, 100 and 150 g/l of Arkofix NF (DMDHE based) and Appretan N9211 (acrylic copolymer), were taken. The finish was applied at normal and shock cure. The effects of finish on pilling resistance, dimensional stability, smoothness, tear strength, light fastness, Berger whiteness and yellowness index of plain fabrics were investigated.FindingsThe changes in the characteristics of the finished fabrics were compared with unfinished fabrics. This study revealed that at 40 g/l of Arkofix NF and Appretan N9211 using a normal cure would improve the pilling resistance, dimensional stability and SA of the plain fabrics. Whereas, there was no adverse effect observed on tear strength, light fastness, Berger whiteness and yellowness index of plain fabrics at these conditions.Originality/valueUnlike the previous studies, this paper proposed the single finish formulation where the functional characteristics of the plain rayon and rayon cotton fabrics meet the general requirement of a customer.

Ester crosslinking on cellulose with pyromellitic acid for anti-wrinkle finishing

Aromatic carboxylic acids were investigated for anti-wrinkle finishing on cotton fabrics as it caused less damage to fibers. However, its application was limited to its poor water solubility. In this study, pyromellitic acid (PMA) was applied for anti-wrinkle finishing on fabric in 30%(w/w) ethanol solution instead of water. The optimum process parameters, such as concentration, bath pH, catalyst dosage, curing condition, were analyzed by orthogonal test for crosslinking cellulose. The surface morphology changes of treated fibers were recorded by scanning electron microscope (SEM). The possible reactive mechanism between PMA and cellulose was discussed by means of Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyses (TGA), in-situ temperature-dependent Fourier transform infrared spectroscopy (FTIR). The results demonstrated that the optimized process for PMA crosslinking cellulose was PMA 0.3 mol/L, bath pH 1.5, sodium hypophosphite (SHP, NaH2PO2) 0.10 mol/L, baking condition 180 °C*1.5 min. The bath pH and curing temperature were the primary factors for fabric wrinkle resistance and strength lose, respectively. After repeated laundering, the strength loss of treated samples with PMA was obviously lower than that of aliphatic carboxylic acid and dimethylol dihydroxy ethylene urea (DMDHEU, 2 D resin). Meanwhile, PMA had less effect on fiber surface morphology and the fiber strength lose was mainly from the damage accumulation of macromolecular chains in fibers. The SHP catalytic action in PMA was much lower than that in aliphatic carboxylic acids for esterification. Moreover, the ortho carboxylic groups on PMA not only esterified with cellulose directly, but also dehydrated into anhydride and further reacted with cellulose. The crosslinking between PMA and cellulose was mainly by direct esterification rather than indirect esterification by anhydride intermediate. The results provided new insights for the application of insoluble crosslinker on cellulose.

Impregnation of poplar wood with multi-functional composite modifier and induction of in-situ polymerization by heating

Herein, a modified wood with greatly improved mechanical properties and reduced hygroscopicity was successfully prepared. The effects of the impregnation of multi-functional composite modifier on the chemical, thermal and morphological properties of poplar wood were also studied by X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analyzer (TGA) and Scanning Electron Microscopy- Energy-Dispersive X-ray Analysis (SEM-EDXA). The multi-functional composite modifier was fabricated by methylolurea, dimethylol dihydroxy ethylene urea (DMDHEU), carbamide and silica sol. Cross-linking reaction happened between the wood cell wall and the multi-functional composite modifier. The position peaks in the XRD pattern didn’t change obviously, which indicated the crystal structure of cellulose was not noticeably affected by the chemical modification. The FT-IR analysis showed that the intensity of hydroxyl (-OH) and carbonyl (C = O) absorption peaks decreased, which was attributed to the -NHCH2OH of the modifier reacted with the hydroxyl and carbonyl of the wood. Meanwhile the Si-O-Si bond and Si-O-C bond formed between the wood structure and silica sol by in-situ polymerization. The TGA curve showed the thermal stability of the modified wood. The micrographs and major elements of the untreated and modified wood were observed by SEM-EDXA.

Study on the Grafting of Chitosan-Essential Oil Microcapsules onto Cellulosic Fibers to Obtain Bio Functional Material

The purpose of this work was to prepare chitosan–essential oil microcapsules using the simple coacervation method and to graft them onto cellulosic fibers to obtain bio functional textile. The microcapsules morphology was characterized by optical microscopy. The 2D dimethyloldihydroxyethylene urea resin (DMDHEU) was used as a binding agent to graft microcapsules on the surface of cellulosic fibers. Scanning Electron Microscopy (SEM) photographs and Attenuated Total Reflectance-Fourier Transformed Infrared (ATR-FTIR) analyses were performed to prove the interaction between cellulosic fibers and microcapsules. Furthermore, the properties of the different fabrics such as mechanical strength and air permeability were investigated. Furthermore, washing durability was evaluated. Finally, the antibacterial activity of the finished fibers against the strains Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was evaluated. The results evidence the ability of treated fabrics to induce bacteria growth inhibition. The coacervation method is a simple process to incorporate cinnamon essential oil on the cellulosic fiber’s surface. The use of essential oils as active agents seems to be a promising tool for many protective textile substrates such as antimicrobial masks, bacteriostatic fabrics and healthcare textiles.

Synergistic Effect of Nitric Oxide for Wound Healing Using Etherification of Cotton

The aim of the present study was to explore the synergistic effect of nitric oxide, chitosan and gelatin-grafted cotton for wound healing. Grafted cottons were prepared by etherification process where hydroxyl group of chitosan and hydroxyl group of cotton formed ether bond with dimethylol dihydroxy ethylene urea. Photomicrography and SEM studies showed the changes in cotton fibres before and after grafting process. Chitosan-grafted cotton (formulation F1) and chitosan-gelatin-grafted cotton (formulation F2) showed thickening and constriction in fibres after grafting process. Hence, the change in cotton fibres as compared to initial cotton indicated the completion of grafting process. Nitrite contents for formulations F1 and F2 were found to be 90.29% and 92.12%, respectively, with prolonged release of nitric oxide for 24 h. The bonding was confirmed by FTIR study due to strong intra- and inter-hydrogen bonding and weak van der Waals interactions. The bonding of grafted solution to cotton fibre might be due to interaction between various constituent groups of polymer chain with chitosan and cotton. Antimicrobial study of the formulations (F1 and F2) on E. coli and S. aureus revealed that both the formulations showed inhibition on E. coli. Furthermore, results of animal study proved that formulation F2 is synergistically effective when compared to control group as nitric oxide directly affected the wound healing process. In animal study, the formulation F2 showed 70% wound closure in comparison to 55% in formulation F1. Grafted cotton using etherification process shows potential to become commercial wound healing system in near future.

Effects of Laundering on Moisture Management and Air Permeability of Different Chitosan Treated Nylon 6,6 Elastane Fabrics Using EDTA and Triton X-100

Abstract This study investigates the effect of washing fabrics (nylon 6.6 powernet knitted fabrics with 30% spandex) treated with chitosan on their moisture management and air permeability. The knitted fabrics were treated with three different solutions of chitosan and dimethylol dihydroxyethylene urea (DMDHEU); in addition to chitosan and DMDHEU, one solution contained the complexing agent ethylenediaminetetraacetic acid (EDTA) and the other contained the nonionic surfactant and penetration agent octylphenol ethoxylate. The three solutions were compared in terms of their effect on moisture management and air permeability properties. Nylon fabrics treated and washed with these solutions were characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Nylon fabrics treated with chitosan and DMDHEU showed the potential to transfer liquid moisture to the lower layer and keep the layer next to the skin dry after 20 washes.

Anti-crease Finishing of Cotton Fabrics Based on Crosslinking of Cellulose with Oxidized Sucrose

ABSTRACT In anti-crease finishing, the hydrophilicity of cotton fabric treated with traditional anti-crease finishing agents such as dimethylol dihydroxy ethylene urea (DMDHEU), 1,2,3,4,-butanetetracarboxylic acid (BTCA), citric acid (CA) was reduced significantly. Oxidized sucrose (OS) was prepared by partial oxidation with sodium periodate. The OS was used as a hydrophilic cross-linking agent instead of conventional anti-crease agents. The chemical structure of the OS characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance, and aldehyde groups were found in the OS. The effects of OS mass concentration, catalyst mass concentration, pH, curing temperature and curing time on the crease recovery angle (CRA), whiteness index (WI) and strong retention rate (TS %) of fabrics were studied. The optimal finishing process was an OS mass concentration of 150 g/L, a catalyst mass concentration of 20 g/L, pH 3 and curing for 3 min at160°C. The OS-treated cotton fabrics could obtain a maximum CRA of 245°, WI of 82.8 and TS% of 65%. Compared with DMDHEU, glutaraldehyde, BTCA and CA finishing fabrics, the OS finishing fabric had a shorter wetting time of 5.01 s and a higher water retention.

Heat-induced changes in cellulose nanocrystal/amino-aldehyde biocomposite systems

Cellulose nanocrystals (CNCs) were extracted from natural cellulosic fibres such as bleached cotton and flax with a controlled multi-step sulphuric acid hydrolysis. From the aqueous suspensions of CNCs, the biocomposite films were prepared by casting and evaporation, with an amino-aldehyde (AA) compound in a wide concentration range from 0 to 30%. The AA compound (dimethylol dihydroxy ethylene urea) was considered both as a cross-linker of the CNC and as a matrix polymer for the CNC-reinforced composite system. Two series of films were prepared using different polyols such as sorbitol and glycerol as plasticizers to improve tractability. Heat treatment of the films was performed at elevated temperatures ranging from 140 to 200 °C for 10 min. Results clearly proved that besides temperature, the factors affecting the response of CNC-based nanocomposites to heat treatment were the source of cellulose, the type of plasticizer and the amount of cross-linking agent. Films based on flax–CNC and plasticized with glycerol showed a higher increase in yellowness and a more significant decrease in haze than those derived from cotton–CNC and plasticized with sorbitol, respectively. The cross-linking agent (AA) had a moderating effect on the heat-induced changes of properties. Furthermore, thermal gravimetric analysis (TG) of films revealed that thermal stability of the CNC films improved considerably when AA was added and cross-linking occurred. The increase in Tmax was more significant for the flax–CNC films (from about 230 to 290 °C) than for the cotton–CNC ones (from about 250 to 280 °C).

Tensile and Impact Bending Properties of Chemically Modified Scots Pine

This study deals with the influence of chemical modification on elasto-mechanical properties of Scots pine (Pinus sylvestris L.). The elasto-mechanical properties examined were impact bending strength, determined by impact bending test; tensile strength; and work to maximum load in traction, determined by tensile tests. The modification agents used were one melamine-formaldehyde resin (MF), one low molecular weight phenol-formaldehyde resin, one higher molecular weight phenol-formaldehyde resin, and a dimethylol dihydroxyethyleneurea (DMDHEU). Special attention was paid to the influence of the solution concentration (0.5%, 5%, and 20%). With an increase in the concentration of each modification agent, the elasto-mechanical properties decreased as compared to the control specimens. Especially impact bending strength decreased greatly by modifications with the 0.5% solutions of each agent (by 37% to 47%). Modification with DMDHEU resulted in the highest overall reduction of the elasto-mechanical properties examined (up to 81% in work to maximum load in traction at 20% solution concentration). The results indicate that embrittlement is not primarily related to the degree of modification depended on used solution concentration. It is therefore assumed that molecular size and the resulting ability to penetrate into the cell wall could be crucial. The results show that, in the application of chemically modified wood, impact and tensile loads should be avoided even after treatment with low concentrations.

Oxysucrose polyaldehyde: A new hydrophilic crosslinking reagent for anti-crease finishing of cotton fabrics

For the first time, oxidized sucrose (oxysucrose) was used as a hydrophilic crosslinking reagent instead of conventional anti-crease reagents for cotton fabrics. In this research, the partial oxidization of sucrose with sodium periodate generated multiple aldehydes, which acted as multifunctional cross-linkers and endowed cotton fabrics with anti-crease and hydrophilic function. The results showed that the oxysucrose-treated cotton fabrics obtained the maximum crease recovery angle of 245°, durable press rating of 3.0, and whiteness index of 82.8. Importantly, the oxysucrose-treated samples showed better hydrophilicity that overcomes the hydrophobization deficiency of anti-creased cotton fabrics treated with previously reported dimethylol dihydroxy ethylene urea (DMDHEU), glutaraldehyde (GA), and 1, 2, 3, 4,-butanetetracarboxylic acid (BTCA). The etherification reaction between the aldehyde group of oxysucrose and the hydroxyl group of cellulose was investigated and the possible crosslinking and anti-crease mechanism was proposed.

Use of DMDHEU with novel FR chemical for CO/PET blends

In present study, DMDHEU (dimethylol dihydroxyethyleneurea), which has been used for wrinkle-resistant finishing in textile, was used in FR finishing of CO/PET blends as a crosslinker with novel FR chemical (Fire-off). Flame retardancy performance of CO/PET fabrics treated with Fire-off and Fire-off/DMDHEU were investigated and compared. In addition, wrinkle resistant test was performed for untreated and Fire-off/DMDHEU treated fabrics to investigate the effect of the treatment on wrinkle recovery performance of fabrics. Results showed that Fire-off/DMDHEU system is a more effective nitrogen provider than Fire-off alone to enhance the flame retarding performance of the treated CO/PET fabrics through phosphorus-nitrogen synergism, therefore the presence of DMDHEU in the flame retardant finishing system increases the flame resistance of the treated CO/PET fabric. In addition, DMDHEU does not significantly change the wrinkle recovery of fabrics when used with Fire-off.

The effect of DMDHEU modification on physical and biological properties of parallel strand lumbers

In this study, the effect of dimethylol dihydroxyethyleneurea (DMDHEU) modification with four different concentration levels on several properties of parallel strand lumbers (PSLs) produced from poplar veneer strands with phenol and melamine formaldehyde adhesives was studied: density, moisture content, water absorption, thickness swelling, dimensional stability, wettability and decay resistance against C. puteana and T. versicolor attacks. Accelareted aging test was conducted in order to evaluate any loss in effectiveness in decay resistance and dimensional stability due to possibility of cleavage of adhesive bonds in lumbers in outdoors. The PSLs produced with modified strands presented higher density and dimensional stability related with their weight gain but lower moisture content, thickness swelling and water absorption than the controls. DMDHEU modification of PSLs was found efficacious in suppressing brown and white rot fungi attacks, but the protective effect was low when lumbers were aged. PSLs manufactured from rotary peeled veneer strands modified with 5% weight gain of DMDHEU and phenol formaldehyde adhesive showed the most promising results for the investigated properties.

Effect of chemical treatments on the mechanical properties of technical flax fibres with emphasis on stiffness improvement

The weak visco-elastic interphase between elementary fibers in a reinforcing technical flax fiber is presumed to play a crucial role in the stiffness reduction during loading. To avoid this stiffness reduction, ethanedial (glyoxal), 3-aminopropyltriethoxysilane (APS) and dimethyloldihydroxyethylene urea (DMDHEU) were investigated as potential fiber treatments in this paper. Tensile tests on single technical fibers show that treating the fibers in an aqueous 3 wt% glyoxal solution was sufficient to increase the technical fiber modulus from 41.6 ± 2.3 GPa to 57.3 ± 2.9 GPa. Further, spectroscopic techniques (FTIR, NMR and XPS) detected increased amounts of acetal and ester bonds after glyoxal treatment. This suggests that cross-linking has taken place between pectin and hemicellulose molecules in the amorphous interphase between elementary fibres. APS and DMDHEU treatments were less successful in improving the technical fibre stiffness due to their lower reactivity towards hydroxyl functionalities compared to glyoxal.