OH Groups Of Cellulose Research Articles

Effect of isomeric polysaccharides on heteroaggregation of nanoplastics in high ionic strength conditions: Synergies of morphology and molecular conformation

Polysaccharides with various molecular structures and morphology may influence the aggregation kinetics of nanoplastics. This study used various characterization methods to elucidate the heteroaggregation mechanism of polystyrene nanoplastics (PSNPs) in the presence of polysaccharides (ionic strength (IS) 1-800mM NaCl and 0.01-60mM CaCl2). The results showed that under high IS, cellulose (CL) accelerated the heteroaggregation of PSNPs, and the aggregation rate of PSNPs increased by approximately 62.05%, while amylose (AM) had little effect (10.38%). Compared with AM (43.2nm), the morphology of the CL (78.4nm) gully had improved surface roughness, leading to its decisive role in the heteroaggregation of PSNPs. Quantum chemistry calculations indicated that van der Waals forces of PSNPs-CL systems (-217.28kJmol-1) were stronger than those of PSNPs-AM systems (-184.62kJmol-1) based on the subtle molecular conformation differences between CL and AM (opposite and same sides of OH groups in CL and AM, respectively). The morphology and molecular conformation of polysaccharides collaboratively controlled the heteroaggregation of PSNPs. Because the morphology of polysaccharides was based on their molecular conformation, the latter is the most critical factor. These findings provide new insights into the effects of PSNPs stability in the environment.

Enhancement of Visible Light Antibacterial Activities of Cellulose Fibers from Lotus Petiole Decorated ZnO Nanoparticles.

Cellulose/ZnO (CZ) nanocomposites are promising antimicrobial materials known for their antibiotic-free nature, biocompatibility, and environmental friendliness. In this study, cellulose fibers extracted from lotus petioles were utilized as a substrate and decorated with various shapes of ZnO nanoparticles (NPs), including small bean, hexagonal ingot-like, long cylindrical, and hexagonal cylinder-shaped NPs. Increasing zinc salt molar concentration resulted in highly crystalline ZnO NPs forming and enhanced interactions between ZnO NPs and -OH groups of cellulose. The thermal stability and UV-visible absorption properties of the CZ samples were influenced by ZnO concentration. Notably, at a ZnO molar ratio of 0.1, the CZ 0.1 sample demonstrated the lowest weight loss, while the optical band gap gradually decreased from 3.0 to 2.45eV from the CZ 0.01 to CZ 1.0 samples. The CZ nanocomposites exhibited remarkable antibacterial activity against both Staphylococcus aureus (S. aureus, Gram-positive) and Escherichia coli (E. coli, Gram-negative) bacteria under visible light conditions, with a minimum inhibitory concentration (MIC) of 0.005mg/mL for both bacterial strains. The bactericidal effects increased with higher concentrations of ZnO NPs, even achieving 100% inhibition. Incorporating ZnO NPs onto cellulose fibers derived from lotus plants presents a promising avenue for developing environmentally friendly materials with broad applications in antibacterial and environmental fields.

Biochemical characterisation of cellulose and cell-wall-matrix polysaccharides in variously oxidised sugar-beet pulp preparations differing in viscosity

Sugar-beet pulp (SBP) is an abundant, cellulose-rich, non-food by-product of agriculture. Oxidised SBP (oP) has valuable viscosity attributes, and different oxidation protocols yield higher- or lower-viscosity oP. We investigated how SBP polysaccharides change during oxidation, since these changes must define oP quality. Oxidation solubilised much pectin and hemicellulose; however, most cellulose stayed insoluble. Fresh SBP contains negligible ‘hemicellulose a’ (=alkali-extractable polysaccharides that precipitate upon acidification), but oxidation created abundant glucose-rich ‘hemicellulose a’ from SBP cellulose. We propose that the cellulose acquired COOH groups, conferring alkali-extractability and admitting more water, thereby augmenting viscosity. The pectin and hemicellulose molecules that were retained during oxidation had been partially depolymerised, and their median Mr correlated negatively with oP viscosity. We developed a novel procedure to explore cellulose's permeability by measuring the ingress of tritium from [3H]water into microfibrils and its retention during desiccation. In high-crystallinity Avicel, 75 % of the cellulose's OH groups were inaccessible to [3H]water, whereas filter-paper cellulose acquired the theoretical maximum 3H, indicating an open structure. Retention of 3H by oP preparations correlated positively with viscosity, indicating that increased cellulose accessibility generates a viscous oP. In conclusion, depolymerisation and solubilisation of matrix polysaccharides, accompanied by increasing water-accessibility of cellulose, enhanced SBP's viscosity.

In-situ growth of hexaconazole/polydopamine/hexadecyltrimethoxysilane in multi-scale structured wood to prepare superhydrophobic wooden materials with decay resistance

Using the layered channels of wood and its unique mesoporous microstructure, hexaconazole, polydopamine (PDA), and hexadecyltrimethoxysilane (HDTMS) were grown and deposited in-situ on the surface and interior of wood. Using this method, a superhydrophobic wood composite with decay resistance was prepared. Hexaconazole inhibited wood fungal decay, and the mass losses of wood were 0 and 0.06% with a retention of 140 g/m3 after laboratory decay tests for 12 weeks by using Trametes versicolor and Gloeophyllum trabeum, respectively. More importantly, through the oxidative self-polymerization of PDA, the adhesive PDA anchored hexaconazole nanoparticles to form a stable core–shell structure that increased the surface roughness of wood. In addition, based on the association of PDA with hydrophilic –OH groups in cellulose and hemicelluloses in wood, long-chain HDTMS was deposited on the surface of wood to form a superhydrophobic multifunctional wooden material with a water contact angle (WCA) of 154°. Based on its multifunctional and inherent durability, the wood also showed good chemical stability and resistance to UV, high- temperature, and high-humidity environments.

The Effect of Sodium Hydroxide (NaOH) Concentration on Oil Palm Empty Fruit Bunch (OPEFB) Cellulose Yield

Cellulose is one of the renewable resources and has become a core target among researchers in recent times to make sustainable biopolymer-based materials. The extraction of cellulose from oil palm empty fruit bunch (OPEFB) by using 4%-13% sodium hydroxide (NaOH) and undergoes bleaching process with 1.7% sodium chlorite solutions (NaOCl) has been done in this study. The maximum yield of cellulose (89.78%) was obtained with 4% NaOH. The effectiveness of NaOH treatment to obtain the cellulose was reflected in Fourier Transform Infrared (FTIR) analysis where the frequency of the C=C aromatic group of lignin resonated around 1600 cm−1 to 1590 cm−1 has been reduced in alkali treatment and disappeared after the bleaching treatment. Meanwhile, the peak for -OH group of cellulose and the -CH methylene group was observed at around 3330 cm−1 and 2900 cm−1 respectively. It was found that increasing the NaOH concentration increased the yield of cellulose to some extent.

Physicochemical Properties of Cellulose extracted From Hom Thong Banana Peels

Bananas are one of the most popular fruits in the world, yet only around 12% of them are consumed, posing an environmental problem. The goal of this research is to extract Hom Thong banana cellulose, which is the major component of banana peels. Fat analysis was used to extract and bleach Hom Thong banana cellulose, followed by soaking in 15% hydrogen peroxide for 3 h. The Hom Thong banana peel cellulose was washed and dried at 60 °C for 10 h. The obtained Hom Thong banana cellulose was characterized in terms of fatty acid profile, intermolecular interactions, and thermal analysis by using gas chromatography, FT-IR, and DSC techniques, respectively. The results showed that the content of palmitic acid (C16:0) in the post-evaporated ethanolic extract is larger than in pre-evaporated ethanolic extract, with a ratio of 44.91% and 38.62%, respectively. At a ratio of 26.19% and 31.56%, the post-evaporation of the ethanolic extract contained less linoleic acid (18:2cis) than the pre-evaporation of ethanolic extract. Intra-molecular interactions between OH groups of cellulose were shown by FT-IR spectra. DSC thermograms revealed that the extracted cellulose had good thermal characteristics and was appropriate for the food and cosmetic industries.

Proton Conductive, Low Methanol Crossover Cellulose-Based Membranes.

This work describes the development of sulfated cellulose (SC) polymer and explores its potential as an electrolyte-membrane for direct methanol fuel cells (DMFC). The fabrication of our membranes was initiated by the preparation of the novel sulfated cellulose solution via controlled acid hydrolysis of microcrystalline cellulose (MCC). Ion-conductive crosslinked SC membranes were prepared following a chemical crosslinking reaction. SC solution was chemically crosslinked with glutaraldehyde (GA) and cured at 30 °C to produce the aforementioned membranes. Effects of GA concentration on methanol permeability, proton conductivity, water uptake and thermal stabilities were investigated. The crosslinking reaction is confirmed by FTIR technique where a bond between the primary OH groups of cellulose and the GA aldehyde groups was achieved, leading to the increased hydrophobic backbone domains in the membrane. The results show that the time of crosslinking reaction highly affects the proton conduction and methanol permeability. The proton conductivity and methanol crossover (3M) of our GA crosslinked SC membranes are 3.7 × 10−2 mS cm−1 and 8.2 × 10−9 cm2 s−1, respectively. Crosslinked sulfated cellulose films have lower ion conductivity than the state-of-the-art Nafion (10.2 mS cm−1); however, the methanol crossover is three orders of magnitude lower than Nafion membranes (1.0 × 10−5 cm2 s−1 at 1 M). Such biofilms with high methanol resistivity address the major hurdle that prevents the widespread applications of direct alcohol fuel cells.

Poly(vinylidene fluoride) Modified Commercial Paper as a Separator with Enhanced Thermal Stability and Electrolyte Affinity for Lithium‐ion Battery

Commercial paper is of great potential as a ready‐made substrate to make battery separator due to superior electrolyte affinity of cellulose. Nevertheless, the direct utilization of commercial paper as a separator is impracticable because of its micro‐sized holes between coarse cellulose fibers, which might induce short circuits. Herein, a novel reinforced composite separator is proposed by modifying commercial paper (CP) with high‐dielectric polymer poly(vinylidene fluoride) (PVDF) via a vacuum filtration method. The paper substrate enables excellent electrolyte wettability and high ionic conductivity of the CP‐PVDF composite separator due to the superior electrolyte affinity of cellulose molecule. Meanwhile, the strong hydrogen bonds between F atoms in PVDF and H atoms in the ‐OH groups of cellulose endow the separator with high thermal stability and mechanical strength. Moreover, the CP‐PVDF exhibits outstanding interfacial compatibility toward Li metal anode and guarantees the prominent cycle durability of symmetric Li/Li cells up to 600 h. As a result, the LiFePO4/Li cells assembled with CP‐PVDF separator show dramatic rate performance with high discharge capacity of 113.7 mAh g−1, and prolonged cycle life at 5 C. This work indicates that the paper‐based composite membranes possess great potential for high‐safety and electrochemical performance batteries.

Pd supported on clicked cellulose-modified magnetite-graphene oxide nanocomposite for C-C coupling reactions in deep eutectic solvent

Cellulose-modified magnetite-graphene oxide nanocomposite was prepared via click reaction and utilized for immobilization of palladium (Pd) nanoparticles without using additional reducing agent. The abundant OH groups of cellulose provided the uniform dispersion and high stability of Pd nanoparticles, while magnetite-graphene oxide as a supporting material offered high specific surface area and easy magnetic separation. The as-prepared nanocomposite served as a heterogeneous catalyst for the Heck and Sonogashira coupling reactions in various hydrophilic and hydrophobic deep eutectic solvents (DESs) as sustainable and environmentally benign reaction media. Among the fifteen DESs evaluated for coupling reactions, the hydrophilic DES composed of dimethyl ammonium chloride and glycerol exhibited the best results. Due to the low miscibility of catalyst and DES in organic solvents, the separated aqueous phase containing both of the catalyst and DES can be readily recovered by evaporating water and retrieved eight times with negligible loss of catalytic performance.

A facile method to control the phase behavior of hydroxypropyl cellulose

We report a facile chemical method to convert the hydroxyl groups of hydroxypropyl cellulose (HPC) into carbamates. It was achieved by the reaction of HPC with N-methyl carbamoylimidazole, which is a safe and easy to handle replacement for the particularly hazardous reagent methyl isocyanate. Using a series of HPC with a range of molar substitution of hydroxypropyl groups, we synthesized HPC methylcarbamates showing lower critical solution temperature (LCST) in the range between 94 and 15 °C. A linear dependence of LCST versus methylcarbamate degree of substitution is observed. The lower the initial hydroxypropyl content of HPC, the greater the effect of methylcarbamate on the LCST. Surface tension study showed that methylcarbamate modification has an insignificant effect on the hydrophilic-hydrophobic balance of the macromolecules below LCST unless the molecular substitution of hydroxypropyl groups is so low (0.8) that the native cellulose OH groups can react with N-methyl carbamoylimidazole.

Mixed oxide-polyaniline composite-coated woven cotton fabrics for the visible light catalyzed degradation of hazardous organic pollutants

Clean water and sea free of organic pollutants are among the 17 United Nation Sustainable Development Goals (SDGs). In this global concern, the design of efficient, stable and recyclable catalytic materials remains challenging. In this context, we designed a series of mixed oxide-modified cotton fabrics and their related composites and interrogated their propensity to catalyze the degradation of methyl orange (MO) (a model pollutant). More specifically, functional cotton fabrics (CF) coated with RuO2–TiO2 based-photocatalysts were obtained by dip-coating method at neutral pH. A layer of Polyaniline (PANI) was prepared by in situ oxidative polymerization of the aniline monomer on 4-diphenylamine diazonium salt (DPA) modified-RuO2–TiO2 nanoparticles (NPs) coated-CF. The modified CFs catalyzed photodegradation and mineralization of MO under visible light, which depended on polyaniline mass loading. The CF/RuO2–TiO2/DPA@PANI obtained by in situ polymerization was the best catalyst due to DPA adhesive layer for polyaniline to RuO2–TiO2, and the strong attraction force between cellulose OH groups and anilinium during polymerization. The photodegradation rate constant was 0.101, 0.0532, 0.0775 and 0.0828 min−1 for RuO2–TiO2/DPA@PANI, RuO2–TiO2, RuO2–TiO2/PANI and RuO2–TiO2/DPA/PANI coated-CFs, respectively. The catalytic activity is favored by the photoactive species (OH·, $${\mathrm{O}}_{2}^{-}$$ ) which are formed by the excitation of electrons under visible light but also by the electronic exchanges at the RuO2//TiO2, RuO2–TiO2//PANI and RuO2–TiO2/PANI//CF interfaces. CF/RuO2–TiO2/DPA/PANI photocatalyst was stable under simulated sunlight and reusable three times. A mechanism is proposed to account for the efficient CF catalytic properties.

Dependence of cellulose dissolution in quaternary ammonium acetates/DMSO on the molecular structure of the electrolyte: use of solvatochromism, micro-calorimetry, and molecular dynamics simulations

We studied the dissolution of microcrystalline cellulose (MCC) at 60 °C in binary mixtures of dimethyl sulfoxide (DMSO) and the following quaternary ammonium acetates (QAAcOs): benzyl-trimethylammonium, NBzMe3AcO; diallyl-benzyl-methylammonium, NAl2BzMeAcO, tetra(n-butyl)ammonium (NBu4AcO), and tribenzyl-methylammonium, NBz3MeAcO (Al, Bu, Bz, Me, AcO refer to allyl, 1-butyl, benzyl, methyl and acetate group, respectively). We observed the following MCC dissolution order (given as wt%): NBu4AcO > NAl2BzMeAcO > NBz3MeAcO ≫ NBzMe3AcO. To explain this result we used the combined data of: (1) solvatochromism to calculate the following binary solvent (b-solvent) descriptors that are important for MCC dissolution: empirical polarity, Lewis acidity, Lewis basicity, dipolarity, polarizability; (2) isothermal titration micro-calorimetry to calculate the enthalpy of interaction (ΔH) of β-cyclodextrin (cellulose model) with QAAcO/DMSO-acetonitrile; (3) molecular dynamics simulations to calculate solvent-induced separation of cellulose chains; average number of hydrogen bonds between acetate ions and cellulose OH-groups, and average composition of the biopolymer solvation layer. We offer the following pieces of evidence to show the importance of hydrogen bonding for the efficiency of cellulose dissolution: the orders of b-solvent basicity and of |ΔH| are parallel to its cellulose dissolution efficiency; the biopolymer solvation layer of efficient b-solvents (e.g., NBu4AcO-DMSO) contains more ionic liquid ions and less DMSO molecules than that of NBz3MeAcO, leading to pronounced biopolymer chain separation, hence eventual dissolution. Our approach shows the power of the combined use of several techniques to rationalize the requirements for efficient cellulose solvents.

Bacterial cellulose sponges obtained with green cross-linkers for tissue engineering.

Three-dimensional (3D) porous structures with controlled pore size and interconnected pores, good mechanical properties and biocompatibility are of great interest for tissue engineering. In this work we propose a new strategy to obtain highly porous 3D structures with improved properties using bacterial cellulose (BC) and eco-friendly additives and processes. Glucose, vanillin and citric acid were used as non-toxic and cheap cross-linkers and γ-aminopropyltriethoxysilane was used to partially replace the surface OH groups of cellulose with amino groups. The efficiency of grafting and cross-linking reactions was confirmed by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The morphological investigation of BC sponges revealed a multi-hierarchical organization after functionalization and cross-linking. Micro-computed tomography analysis showed 80-90% open porosity in modified BC sponges. The thermal and mechanical properties of the sponges were influenced by the cross-linker type and concentration. The strength-to-weight ratio of BC sponges cross-linked with glucose and citric acid was 150% and 120% higher compared to that of unmodified BC sponge. In vitro assays revealed that the modified BC sponges are non-cytotoxic and do not trigger an inflammatory response in macrophages. This study provides a simple and green method to obtain highly porous cellulose sponges with hierarchical design, biocompatibility and good mechanical properties.

Composite Membranes Derived from Cellulose and Lignin Sulfonate for Selective Separations and Antifouling Aspects.

Cellulose-based membrane materials allow for separations in both aqueous solutions and organic solvents. The addition of nanocomposites into cellulose structure is facilitated through steric interaction and strong hydrogen bonding with the hydroxy groups present within cellulose. An ionic liquid, 1-ethyl-3-methylimidazolium acetate, was used as a solvent for microcrystalline cellulose to incorporate graphene oxide quantum dots into cellulose membranes. In this work, other composite materials such as, iron oxide nanoparticles, polyacrylic acid, and lignin sulfonate have all been uniformly incorporated into cellulose membranes utilizing ionic liquid cosolvents. Integration of iron into cellulose membranes resulted in high selectivity (>99%) of neutral red and methylene blue model dyes separation over salts with a high permeability of 17 LMH/bar. With non-aqueous (alcohol) solvent, iron–cellulose composite membranes become less selective and more permeable, suggesting the interaction of iron ions cellulose OH groups plays a major role in pore structure. Polyacrylic acid was integrated into cellulose membranes to add pH responsive behavior and capacity for metal ion capture. Calcium capture of 55 mg Ca2+/g membrane was observed for PAA-cellulose membranes. Lignin sulfonate was also incorporated into cellulose membranes to add strong negative charge and a steric barrier to enhance antifouling behavior. Lignin sulfonate was also functionalized on the commercial DOW NF270 nanofiltration membranes via esterification of hydroxy groups with carboxyl group present on the membrane surface. Antifouling behavior was observed for both lignin-cellulose composite and commercial membranes functionalized with lignin. Up to 90% recovery of water flux after repeated cycles of fouling was observed for both types of lignin functionalized membranes while flux recovery of up to 60% was observed for unmodified membranes.

Topochemical engineering of composite hybrid fibers using layered double hydroxides and abietic acid.

Topochemical engineering of hybrid materials is an efficient way of synthesizing hydrophobic and highly tensile fiber composites by utilizing the intermolecular hydrogen bonds in natural materials. These materials include wood pulp fibers, abietic acid (resin acid) and inexpensive metal salts. In this work, a hybrid composite was created using bleached and unbleached kraft pulp fibers as cellulose platform. In situ co-precipitation of layered double hydroxide (LDH) was performed to grow LDH crystals on the surface of the cellulose fibers, followed by the immobilization of abietic acid (AA) on LDH-grafted cellulose. Here we aimed to benefit from the hydrogen bonding between –OH groups of cellulose and LDH, and the –COOH groups of AA to obtain charge-directed assembly of one material on the other material. Thus, composite hybrid fibers (C-HF) were produced and then characterized by optical (CAM), spectroscopic (XRD, IR) and microscopic techniques (SEM) to determine their average length and distribution, structure and purity, bonding, and morphology. These fibers further were tested for water contact angle (hydrophobicity), oil absorption (lipophilicity), tensile strength and ISO brightness measurements. The performance of C-HF was compared with unmodified reference fibers (REF), fibers composed with only AA (C-F) and LDH-hybridized fibers (HF). The results revealed a variety of correlations between materials and their properties due to characteristic surface morphology, functional groups, hydrogen bonding and natural co-materials such as lignin and hemicelluloses. Attractive and repulsive van der Waals forces between material entities play a crucial role in the resulting properties.

Selective oxidation of cellulose, mediated by N-hydroxyphthalimide, under a metal-free environment

The generation of the phthalimide-N-oxyl (PINO) free radical from its N-hydroxylphthalimide (NHPI) precursor under a metal free environment, to selectively oxidize the primary OH groups in cellulose is reported.

Surface functionalisation of microfibrillated cellulose (MFC) of cocoa pod husk with Ƴ-Methacryloxypropyltrimethoxysilane (MPS)

Significant growing on environmental awareness has led researchers to study the surface functionalisation of cellulose nanofiber using natural renewable resources. This study aims to improve the percentage swelling of microfibrillated cellulose (MFC) of cocoa pod husks, crops-by product with Ƴ- methacryloxypropyltrimethoxysilane (MPS). Investigation on the effect of cocoa pod husk (CPH) microfibrillated cellulose (MFC-CPH) amount, MPS amount, MPS concentration and the reaction time to the percentage of swelling property of MFC-CPH treated with MPS was carried out. Composition amount of CPH -MFC, MPS, MPS concentration and the reaction time were varied from range of 0.5-6 gram, 1-9 mL, 5-15 w/w % and 2-24 hours respectively. Based on evaluation of percentage swelling obtained, it showed that the surface hydrophobicity of MFC-CPH treated with MPS could be increased due to the chemical bonds interaction that formed during silane treatment. The lowest percentage swelling of treated MFC-CPH-MPS is 14.96 % and the highest is 94.87 %. The untreated and treated MFC-CPH were then observed using fourier transform infrared (FT-IR) and field emission scanning electron microscopy (FESEM) for any change of structural and morphology. FT-IR results shows that there is reduction of OH groups in cellulose and addition of Si groups after silane treatment. There is also a change on the surface of MFC-CPH fibers after silane treatment as MFC-CPH fibers surface become rough due to deposited of MPS on MFC-CPH fibers.

Characterization of Individual Hydrogen Bonds in Crystalline Regenerated Cellulose Using Resolved Polarized FTIR Spectra.

Cellulose nanofibers (CNFs), which are directly isolated as a native form, have drawn considerable attention as eco-friendly and distinctive material to be partly substituted for fossil products. In addition to the increasing attention to the native CNFs, conventional regenerated cellulose having cellulose II crystals also attracts more attention because of its cost-effective method of production in a moderately easy and repeatable fashion. Inter- and intramolecular hydrogen bonds are, in particular, thought to contribute greatly to the physical properties of cellulosic commercial products. More than half century ago, Marchessault et al. attempted to directly assign the hydroxyl (OH) group vibrations related to hydrogen bonding in infrared (IR) spectra. The assignment, however, has not been significantly updated. One reason for the delayed assignments is the difficulty in preparing pure cellulose II. Here, we show successful IR assignments of the interacted OH groups in cellulose II by using the nematic ordered cellulose to prepare a highly oriented regenerated film. The film had anisotropic crystalline domains, which provided a clearly resolved component in the IR spectra. The OH bands were well assigned, and this IR assignment becomes an effective tool to understand the structure–property relationship for engineering advanced regenerated cellulose materials.

Simultaneous Cationization and Antimicrobial Treatment of Cotton Khadi Fabric with Poly-Hydroxy Methyl Amino Sillicone (PHAMS) and Poly Ethylene Glycol (PEG)

Cotton Khadi fabric is treated with eco-friendly anti- microbial agents like Polyethylene Glycol (PEG -200), Poly-Hydroxyl Amino Methyl Silicone (PHAMS) and Citric Acid (CA) individually and in their blends as compared to treatment with epoxy-propyl-trimethyl-ammonium chloride (EPTAC) in presence of MgCl2 as mild acidic catalyst by low tensioned padding and drying at 100°C for 10 min. followed by curing at 120°C for 4 min. to investigate the effect of such treatment on important textile related properties and microbial resistance and dye-ability with reactive dye. For presence of –OH group, PEG, PHAMS and EPTAC have ability to react with –OH groups of cellulose under acidic catalyst to bound to cellulose macromolecules forming ether linkage and can produce a modified cationized cotton attaching –NR3+ groups of EPTAC and –NHR2+or –NH3+groups of PHAMS. Highest Antimicrobial and salt free dyeing with reactive dye was achieved by combined treatment of PEG and PHAMS (in 3:1 ratio) in presence of 1/5th of magnesium chloride. FTIR, XPS and TGA studies have been carried out to understand the nature of reaction and modification occur to support reaction mechanism discussed. The effectiveness of the antimicrobial properties have been assessed by measuring the loss of tensile strength by soil burial test and also by testing as per AATCC-100 and AATCC-147.

Dimensional Stability and Mechanical Properties of Plantation Poplar Wood Esterified Using Acetic Anhydride

Plantation poplar (Populus ussuriensis) wood was esterified using acetic anhydride without catalysts to improve its dimensional stability. The effects of acetylation temperature (100 °C, 120 °C, and 140 °C) on the dimensional stability, mechanical properties, microstructure, and functional groups of the resulting acetylated wood were systematically investigated. Results showed that the wood acetylated at 100 °C and 120 °C had an improved dimensional stability and comparable mechanical properties to those of the control wood. Wood acetylated at 140 °C had an improved dimensional stability and decreased mechanical properties as compared to those of the control wood. Scanning electron microscopic (SEM) analysis showed that the wood acetylated at 140 °C had obviously different microstructures than the control wood and the wood acetylated at 100 °C and 120 °C. The changes of functional groups in the acetylated wood were revealed by Fourier transform infrared spectroscopy (FTIR). The –OH groups of cellulose, hemicellulose, and lignin all were shown to participate in the acetylation reaction.