Degree of crosslinking and physical properties of dimethyloldihydroxyethyleneurea/acrylic acid crosslinked cotton fabrics after treatment with various metallic salts

Three metallic salts were used to posttreat dimethyloldihydroxyethyleneurea (DMDHEU)/acrylic acid (AA) crosslinked cotton fabrics, and the results showed that at a given value of the tensile strength retention (TSR), the dry crease recovery angle (DCRA) and wet crease recovery angle (WCRA) of the crosslinked and posttreated fabrics were higher than those of the DMDHEU–AA‐treated fabrics, and those of the crosslinked and posttreated fabrics were in the order of Ag⁺ > Cu⁺² > Al⁺³. The DCRA and TSR values for the crosslinked and posttreated fabrics were higher than those for the DMDHEU–AA‐crosslinked fabrics, and those for the crosslinked and posttreated fabrics were in the order of Ag⁺ > Cu⁺² > Al⁺³; however, WCRA values for the crosslinked and posttreated fabrics were lower than those for the DMDHEU–AA‐crosslinked fabrics, and those for the crosslinked and posttreated fabrics were ranked as Ag⁺ > Cu⁺² > Al⁺³ at a given number of crosslinks per anhydroglucose unit. IR spectra clearly revealed the different interactions and bonding states between the hydroxyl group of the cellulose and the various metallic ions and the strength of the interaction. All crosslinked and posttreated fabric samples showed good odor absorption and antibacterial and washing‐fastness properties. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 584–594, 2005     

Crosslinking of cotton cellulose in the presence of serine and glycine. I. Physical properties and reaction kinetics

Serine and glycine were used to combine with dimethyloldihydroxyethyleneurea (DMDHEU) as crosslinking agents to study the physical properties of the crosslinked fabrics and the reaction kinetics, and find that the bound nitrogen is in the series of DMDHEU ? DMDHEU‐serine > DMDHEU‐glycine at the same resin concentration. The results also show that the wet crease recovery angle (WCRA) value of the treated fabrics for the three crosslinking agent systems is in the series of DMDHEU‐serine > DMDHEU‐glycine > DMDHEU alone at a given dry crease recovery angle (DCRA). The DCRA values of the treated fabrics for DMDHEU alone are higher than those for DMDHEU‐α‐amino acids for a given value of tensile strength retention (TSR). WCRA values for the various treated fabrics is in the rank of DMDHEU‐serine > DMDHEU alone > DMDHEU‐glycine at the same TSR. Rate constants for the various crosslinking agents are in the series of DMDHEU‐glycine > DMDHEU‐serine > DMDHEU alone at the given heated temperatures. Energies needed to crosslink and the values of enthalpies and entropies of activation are all DMDHEU‐glycine > DMDHEU‐serine > DMDHEU alone. Infrared ray (IR) spectra strongly suggest the reaction between DMDHEU and serine and the reaction between the hydroxyl group (cellulose) and serine can occur in the pad‐dry‐cure process, but only a little for the latter. The reaction between the functional groups of serine and the aluminum ion to form a complex also confirm with IR spectrum. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 595–603, 2005     

Degree of crosslinked cotton cellulose with prereacted DMDHEU–AA

Dimethyloldihydroxyethyleneurea (DMDHEU) and acrylic acid (AA) were used to synthesize the dimethyloldihydroxyethyleneurea–acrylic acid product (DMDHEU–AA, mole ratios of DMDHEU/AA = 1/0, 1/1, and 1/2, respectively). Cotton fabrics were treated with the various prereacted DMDHEU–AA products by changing resin concentrations in the bath. We found that the dry crease recovery angle (DCRA) and wet crease recovery angle (WCRA) of the treated fabrics increased with the increase of acrylic acid in the prereacted DMDHEU–AA at the same value of resin concentration in the bath, whereas the tensile strength retention (TSR) showed the inverse tendency. For a given value of number of crosslinks per anhydroglucose unit (CL/AGU), the DCRA and WCRA values of the DMDHEU–AA‐treated fabrics were higher than those for DMDHEU‐treated fabrics. Additionally, agent distribution and the reaction between –COOH of the crosslinking agent and cellulose molecule were also investigated in this study. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1580–1586, 2001     

Physical properties of crosslinked cellulose catalyzed with nano titanium dioxide

Four different carboxylic acids, 1,2,3,4‐butane tetracarboxylic acid (BTCA), maleic acid (MA), succinic acid (SUA), and citric acid (CA), were used as crosslinking agents to treat cotton fabrics in the presence of nanometer titanium dioxide (TiO₂) as a catalyst under UV irradiation. The dry crease recovery angle (DCRA) and wet crease recovery angle (WCRA) values of the treated fabrics were ranked BTCA > MA > CA > SUA and the tensile strength retention (TSR) values were ranked BTCA < MA < CA < SUA at a given resin concentration, catalyst concentration, and irradiation time period. The physical properties of the treated fabrics for nanometer silver/nanometer titanium dioxide (Ag/TiO₂) catalyst showed the same tendency. At a given DCRA, the WCRA values were ranked in the order BTCA ≒ MA > CA ≒ SUA; and at a given value of the TSR, the WCRA and DCRA values were both ranked in the order BTCA > MA > CA > SUA. The softness values of the carboxylic acid treated fabrics in the presence of nanometer TiO₂ catalyst were all better than that of the untreated fabric. Surface deposition of the treated fabrics for BTCA, which contains one vinyl double bond and four carboxylic acid groups, was higher than that for CA, which contains no vinyl double bond. IR spectra and electron spectroscopy for chemical analysis survey spectra showed the ester bond crosslink between the cellulose molecule and the various acids used in this study. The values of DCRA, WCRA, and add‐on of the CA crosslinked fabrics for the mixed catalysts were in the order ZrO₂/TiO₂ < SiO₂/TiO₂ < Ag/TiO₂. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2450–2456, 2005     

Crosslinking of cotton cellulose in presence of alkyl di‐allyl ammonium salts. III. Study on pore structure of treated fabrics from dyeing kinetics

Two kinds of alkyl di‐allyl ammonium salts (alkyl groups = methyl and propyl) as crosslinking agents are combined with dimethyloldihydroxyethyleneurea (DMDHEU) to study rate constants, structural diffusion resistance constants, and other parameters of dyeing. The dye absorptions for the various crosslinking agents are ranked DMDHEU–propyl di‐allyl ammonium salt > DMDHEU–methyl di‐allyl ammonium salt > DMDHEU, and the equilibrium absorption values are ranked DMDHEU–propyl di‐allyl ammonium salt > DMDHEU–methyl di‐allyl ammonium salt > DMDHEU. The dyeing rate constants and structural diffusion resistance constants of the finished fabrics are in the order DMDHEU–methyl di‐allyl ammonium salt > DMDHEU–propyl di‐allyl ammonium salt > DMDHEU; however, the activation energies are ranked inversely. The treated fabrics for DMDHEU–alkyl di‐allyl ammonium salts have a larger pore structure than those for DMDHEU. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 862–866, 2005     

Soap-based detergent formulations: XXIII. Synthesis of p-sulfobenzyl ammonium inner salts and structural correlation with analogous amphoterics

Two series of p-sulfobenzyl ammonium inner salts, RN⁺(CH₃)₂CH₂C₆H₄SO₃⁻ and RCONH(CH₂)₃N⁺−(CH₃)₂CH₂C₆H₄SO₃⁻, where R is a straight chain alkyl group, were prepared by sulfonation of the corresponding quaternary ammonium chlorides. Although both series have excellent lime soap dispersion properties, the former series gave optimum detergency at considerably shorter alkyl chain length than the latter serires. The detergency, lime soap dispersion ability, and solubility of these compounds were compared with those of structurally analogous aliphatic sulfobetaines. Structural variations, such as length and nature of the bridge between the cationic and anionic groups, length of the lipophilic chain, and insertion of an amidopropyl group into the lipophilic portion of the molecule, significantly altered the detergency and solubility but not the lime soap dispersing ability of the amphoterics.     

Adsorption of weak and non-electrolytes by activated carbon

Four activated carbons, one of them commercially available Darco active carbon and the remaining three from a series of coconut charcoals steam activated to varying degrees, are used to study the adsorption of weak and non-electrolytes. Introduction of —CI into the CH₃COOH molecule increases adsorption onto activated carbon while —OH and —NH₂ have the opposite effect. Substitution in the benzene ring shows that adsorption from aqueous solutions is in the order —NH₂, >—OH, >CO₂, >(—OH + —COOH). Effect of polarity of solvent on adsorption capacities is studied in H₂O, CHCl₃ and C₆H₆. Substitution of —Cl into the CH₃COOH molecule invariably increases the adsorption irrespective of the polarity of the solvent. On introducing a specific group in the benzene ring the adsorption is in the order: aniline ? phenol > benzoic acid > salicylic acid in H₂O medium but in CHCl₃ and C₆H₆ media aniline ? phenol > salicylic acid > benzoic acid. However, on comparing the results of individual adsorbates in three media, generally the magnitude of adsorption is H₂O > C₆H₆ ? CHCl₃. Adsorption of lower aliphatic acids (formic to caproic) from aqueous solutions increases regularly as one ascends the homologous series—a behaviour known as Traube's rule; however, of all the surface area available for N₂ adsorption, only a fraction of it is available for adsorption of the aliphatic acids.     

Synthesis, Characterization and Properties of New Lauryl Amidopropyl Trimethyl Ammoniums

A new lauryl amidopropyl trimethyl ammonium methyl carbonate with the formula CH₃(CH₂)₁₀CONH(CH₂)₃N⁺(CH₃)₃CH₃CO₃ ^? was synthesized via a high pressure process with tertiary amines and dimethyl carbonate, and its chemical structure was confirmed using ¹H-NMR spectra, mass spectral fragmentation, and FTIR spectroscopic analysis. In addition, several quaternary ammonium salts with new counterions X^? (X^?=HCO₃ ^?, HCOO^?, CH₃COO^?, CH₃CH(OH)COO^?) were also synthesized by the ion exchange reaction of methyl carbonate quaternary ammoniums with corresponding acids. The surface activities of these compounds were measured, including surface tension (??), critical micelle concentration and minimum surface area (A _min) at 25?°C. Adsorption and micellization free energies of these quaternary ammonium salts in their solutions showed a good tendency towards adsorption at interfaces. The antimicrobial activities are reported for the first time against representative bacteria and fungi for lauryl amidopropyl trimethyl ammoniums. It was found that the antimicrobial potency was Gram-positive bacteria?>?fungi?>?Gram-negative bacteria.     

Oxidation of cyclopentene catalyzed by phosphotungstic quaternary ammonium salt catalysts

A series of phosphotungstic quaternary ammonium salts, Q₃ (PW₁₂O₄₀) and Q₃(PW₄O₁₆) [Q = (C₅H₅)N⁺(C₁₆H₃₃), (C₁₆H₃₃)N⁺(CH₃)₃, (C₄H₉)₄N⁺, and (CH₃)₄N⁺], were used as the catalysts in oxidation of cyclopentene. The catalysts [(C₅H₅)N(C₁₆H₃₃)]₃(PW₄O₁₆) and [(C₁₆H₃₃)N(CH₃)₃]₃(PW₄O₁₆) showed high catalytic activity in the selective oxidation of cyclopentene while using H₂O₂ (50%) as an oxidant and 2-propanol as a solvent. The oxidation products mainly consisted of glutaraldehyde, cis-1,2-cyclopentanediol and trans-1,2-cyclopentanediol. The above-mentioned two catalysts were dissolved completely in the reaction medium during the catalysis process and precipitated themselves from the reaction system after reaction, showing the characteristics of reaction-controlled phase-transfer catalysis. The types of quaternary ammonium cations and the phosphotungstic anions in phosphotungstic quaternary ammonium salts affected catalytic activity.     

Comparison of commercially available quaternary ammonium structures for phase transfer catalysis

A variety of commercially available tetralkyl (R₁R₂R₃R₄N⁺) ammonium chlorides and methyl sulfate salts were examined under phase transfer conditions. For conversion of benzyl chloride to benzyl acetate with aqueous potassium acetate, tri C_8–10 methyl ammonium chloride was the most efficient, with tri C_16–18 methyl ammonium chloride was next. The alkyl trimethyl ammonium chlorides (particularly C_12–14 trimethyl) performed well for the oxidation of benzyl alcohol to benzaldehyde with sodium hypochlorite. Trimethyl tallow, C_16–18 partially unsaturated, ammonium chloride was the catalyst of choice for the dichlorocarbene addition to cyclohexene.     

Study of phase behavior and Congo red dye partitioning in aqueous two-phase systems composed of hydrophilic alcohols (1-propanol/ 1-butanol) and sodium salts

ABSTRACT

The partitioning of the Congo red dye in ATPSs formed by alcohols (1-butanol, 1-propanol)/sodium salts was considered. Binodal and the LLE data were experimentally determined at 298.15 K. The salting-out abilities of the salts follow the order Na₃C₆H₅O₇ > NaH₂PO₄ > C₂H₃ O₂Na. The phase-forming abilities of the alcohols follow the order: 1-butanol > 1-propanol. The four-parameter equation was applied to correlate the binodal curves data. Therefore, The Bancroft and Othmer-Tobias equations were used to prove the reliability of the corresponding LLE data. ATPS composed of 6.5% of 1-butanol and 20% of Na₃C₆H₅O₇ had the highest values of extraction by the yield of 98.54%.     

Exploring the effect of alkyl end group on poly(L-lactide) oligo-esters. Synthesis and characterization

Poly(L-lactide) (PLLA) oligo-esters with α-hydroxyl-ω-alkyl (alkyl = −CH₂−[CH₂−CH₂]_m−CH₃, where m = 1, 2, 4, 5, 6, 7, 8, 9, and 10) end groups were synthesized by ring-opening polymerization of L-lactide (L-LA) catalyzed by tin(II) 2-ethylhexanoate Sn(Oct)₂ in the presence of aliphatic alcohols as initiators (HO−CH₂−[CH₂−CH₂]_m−CH₃, where m = 1, 2, 4, 5, 6, 7, 8, 9, and 10). High yields (~ 62 to 71%) and M _n(NMR) in the range of 2120–2450 Da (PLLA) were obtained. Effects of alkyl end groups on thermal properties of the oligo-esters were analyzed by DSC, TGA and SAXS. Glass transition temperature (T _g) gradually decreases with increase in the percent of−CH₂−[CH₂−CH₂]_m−CH₃ end group, as results alkyl end group provides most flexibility to PLLA. An important effect of alkyl end group on a double cold crystallization (T _c1 and T _c2) was observed, and is directly related with the segregation phase between alkyl end group and PLLA. TGA analysis revealed that PLLA oligo-esters are more thermally stable with docosyl (−C₂₂H₄₅) respect to the butyl (−C₄H₉) end group, probably is due to steric hindrance of the end group (docosyl respect to butyl) toward intermolecular and intramolecular transesterification. SAXS analysis showed that alkyl end group as docosyl restricted the growth of lamellae thickness (D) due to steric hindrance. Characterization of hydroxyl and alkyl end groups in the PLLA oligo-esters was determined by MALDI-TOF, GPC, FT-IR and ¹ H and ¹³ C NMR.     

Direct Decomposition of NO Over Alkaline Earth Metal Oxide Catalysts Supported on Cobalt Oxide

Spinel powders with addition of ZnO into Ga₂O₃–Al₂O₃ were synthesized from a mixed solution of nitrate salts in the presence of aqueous ammonium carbonate under hydrothermal conditions at 150 °C for 48 h. The crystallization of the spinel was promoted by an increase in reaction temperature and time. This powder was studied for the selective reduction of NO with hydrocarbons (CH₄, C₂H₄, and C₃H₆) in the presence of oxygen. High durability was observed for the reduction of NO by C₂H₄ in the presence of water vapor and sulfur oxides, maintaining a high stability over 100 h.     

Transport properties of organic vapours in silicone/clay nanocomposites

Poly(dimethylsiloxane) (PDMS)/clay nanocomposites have been synthesized using a novel ω-ammonium functionalized oligo-PDMS surfactant (PDMS-N⁺(CH₃)₃) and processed in membrane form. In order to relate the clay morphological structure to the degree of dispersion and physical properties of the membrane, the clay ion-exchanged by PDMS-N⁺(CH₃)₃ has been compared to a non-exchanged sodium MMT and to two organoclays organo-modified by using either non-functional alkyl ammonium cations (C₃₈H₈₀N⁺) or hydroxyalkyl ammonium (C₂₂H₄₈ON⁺) cations. Morphological analysis and transport properties (sorption, diffusion and permeability) have been investigated using two penetrants: acetone and n-hexane. The mechanical and rheological properties of the PDMS nanocomposite membranes have also been studied. It has been found a significant effect of the clay organo-modifier on the morphology, physical and barrier properties of the systems.     

N.m.r. relaxation studies of molecular motion in alternating copolymers of styrene and N-substituted maleimides

Spin—lattice and rotating frame relaxation measurements have been made on nine copolymers of styrene with N-n-alkyl maleimides in which the alkyl groups are CH₃, C₂H₅, C₅H₁₁, C₇H₁₅, C₉H₁₉, C₁₂H₂₅, C₁₄H₂₉, C₁₆H₃₃ and C₁₈H₃₇. Five relaxations have been detected which are correlated with existing relaxation work. The highest temperature (αβ) relaxation is associated with the glass transition and the γ-relaxation results from ring twisting in the ordered (helical) parts of the structure. The δ-relaxation occurs only in the C₁–C₇ polymers and reflects movement in helical stacking within the ordered phase while the ε-relaxation occurs only in the C₇–C₁₈ homologues and arises from motion of the pendant alkyl chain in both ordered and disordered regions. The lowest temperature minimum in T₁ is associated in all polymers with methyl rotation. Spin diffusion plays a prominent role in the relaxations and this is used to interpret further the morphology of the samples.     

Soap-based detergent formulations: XVIII. Effect of structure variations on surface-active properties of sulfur containing amphoteric surfactants

Quaternary ammonium amphoteric surfactants have been found in the past to be excellent lime soap dispersing agents and detergents but exhibit unusual solubility behavior. In search of a relationship between chemical structure and surface-active properties, compounds having the following general formula were synthesized: ZN⁺(CH₃)₂(CH₂)_nX⁻, where Z is C₁₂H₂₅-, C₁₄H₂₉-, C₁₆H₃₃-, or C₁₅H₃₁CONHC₃H₆-, n is 2, 3, or 4 and X is SO₃- or OSO₃-. Tertiary amines were converted to sulfobetaines (X=SO₃-) by reaction with (a) butanesultone (n=4), (b) propanesultone (n=3), or (c) sodium 2-bromoethanesulfonate (n=2). An alternate synthesis for the sulfoethylbetaines (n=2) involved the reaction of the tertiary amines with ethylene bromide, followed by treatment with sodium sulfite. All sulfated quaternary ammonium compounds (X=OSO₃-) were synthesized by treatment of the tertiary amine with the appropriate chloroalcohol, followed by sulfation with chlorosulfonic acid. The sulfated quaternary ammonium amphoterics are stable to acid hydrolysis, and alkaline stability improves with increasing bridge chain length. Sulfoethyl amphoterics are less water soluble than sulfobutyl, which in turn are less soluble than sulfopropyl derivatives of the same alkyl chain length. For the most part, the sulfated amphoterics are insoluble but are solubilized by soap. The lime soap dispersing properties improve as the carbon chain bridge length increases for both the sulfates and sulfonates. Formulations of tallow soap, amphoteric surfactant, and sodium silicates gave good detergency in most cases. Presented at the AOCS meeting, Dallas, April 1975.     

Biocidal polymers active by contact. II. Biological evaluation of polyurethane coatings with pendant quaternary ammonium salts

Films of polyurethane were prepared by reaction of hydroxytelechelic polybutadienes carrying covalently bound quaternary ammonium salts with an aliphatic triisocyanate. These coatings exhibited high biocidal activity against Gram-positive and Gram-negative bacteria, yeasts, and moulds. It was found that many parameters controlled the bioactivity such as the time of contact between films and bacteria, the [NCO]/[OH] ratio used to prepare the cured polyurethane, the concentration of quaternary ammonium salts in the coating, and the length of the alkyl chain from C₈ to C₁₆ linked to the quaternary nitrogen atom. A secondary phenomenon of diffusion only observed with the shorter alkyl chains (C₈ and C₁₀) was shown to be due to synthesis residues. After these water-soluble impurities are eliminated, the biocidal activity remains excellent: then it is due only to a contact polymer bacteria. © 1993 John Wiley & Sons, Inc.     

The Copper (II) Complexes of Phenyl-2 Pyridyl Ketone and the Triple Complexes Obtained by Adding Ethylenediamine

Copper salts of low pH (1.8–2.5) combine with phenyl-2-pyridyl ketone to form a ketone complex [(Py–CO–C₆H₅)₂Cu]²⁺. An electrically uncharged complex is obtained at pH > 9 [(Py–C(OH)(C₆H₅)O^?)₂Cu]⁰, liberating two protons from two molecules of the ligand. The stability constant of this complex is β = 16.05. By mixing the copper salts (except the halide) containing this ligand with ethylenediamine, a charged triple complex is obtained at pH < 7 [Py–C(OH)(C₆H₅) O–Cu–NH₂C₂H₄NH₃⁺]²⁺. At pH > 9.5, an uncharged triple complex is obtained: {[(Py–C(OH)(C₆H₅)O^?)₂Cu}₂ · NH₂C₂H₄NH₂}⁰. The copper halide salts produce only an uncharged triple complex; the halide ions are coordinated with the copper atoms. All of these complexes in their solid state, are bi- or polynuclear. As a result, they are magnetically subnormal.     

Synergetic thermodynamic/kinetic separation of C3H8/CH3F on carbon adsorbents for ultrapure fluoromethane electronic gas

Atomic layer etching (ALE) using the environmentally friendly electronic gas fluoromethane (CH₃F) is guided for fabricating nanoscale electronic components. The adsorptive purification of CH₃F provide a viable direction to remove trace amounts of impurities to produce highly pure CH₃F (>99.9999%) for the ALE process. Herein, to remove trace propane (~100 ppm) in CH₃F, we report synergetic thermodynamic and kinetic separation of C₃H₈/CH₃F over glucose-derived carbon molecular sieve CMS-T, (T as pyrolysis temperature). With pore size slightly larger than the kinetic diameter of C₃H₈, CMS-600 allows both strong confined adsorption of C₃H₈ and a higher diffusion rate of C₃H₈ over CH₃F, resulting in a remarkable separation factor of 51.1. Breakthrough experiment demonstrates a high dynamic production capacity of 457 L kg⁻¹ of 7 N CH₃F (<100 ppb of C₃H₈) over CMS-600 with excellent cycling stability. Adsorption purification over carbon provides a feasible approach for industrial hyperpurification of electronic gas.     

Structural characterization and thermal behaviour of block copolymers of polydimethylsiloxane and polyamide having trichlorogermyl pendant groups

Block copolymers having a pendant trichlorogermyl group as a part of polyamide segment? (CO? R′? CO? NH? Ar? NH? )_xCO? R′? CO? and polydimethylsiloxane of general formula [(? CO? R′? CO? HN? Ar? NH)_x? CO? R′? CO? NH(CH₂)₃SiO(CH₃)₂ ((CH₃)₂SiO)_ySi(CH₃)₂(CH₂)₃ NH? ]_n (where R′ = CH₂CH(GeCl₃), CH(CH₃)CH(GeCl₃), CH(GeCl₃)CH(CH₃); Ar = C₆H₄, (? C₆H₃? CH₃)₂, (? C₆H₃? OCH₃)₂, 2,5‐(CH₃)₂? C₆H₂, C₆H₄? O? C₆H₄) were prepared by a polycondensation reaction and characterized using CHN and Ge analysis, Fourier transform infrared (FTIR) and ¹H NMR spectroscopy, thermogravimetric analysis (TGA) and molecular weight determination. They have a lamellar structure with weight‐average molecular weight in the range 1.21 × 10⁵–4.79 × 10⁵ g mol^?1. These copolymers display two glass transition temperatures and have an average decomposition temperature of 489 °C. TGA, FTIR and gas chromatography/mass spectrometry studies indicate that degradation of these block copolymers results in carbon monoxide, oligomeric siloxanes and polyamide fragments. They are thermally stable due to the hydrogen bonded interlinked chains of polyamide, while they absorb water due to the presence of Ge? Cl bonding. Copyright © 2010 Society of Chemical Industry