Dyeing of Lyocell Fabrics with Pigment Dispersion Systems

Lyocell fabrics modified by cationic reagent were dyed with conventional and nanoscale pigment dispersions respectively. The color yield and fastness properties were measured. It is found that the color yield and fastness properties of the dyed lyocell fabrics are influenced by the cationic reagent concentration, the cationization pH, time, and temperature. It is also found that the nanoscale pigment system can give the lyocell fabric a higher K/S value but with lower rub and wash fastness. The wet abrasion time, which is used to indicate the fibrillation tendency of lyocell fabrics, was also measured after the cationization and pigment dyeing. The results show that the multifunctional cationic reagent and the pigment on the lyocell surface could increase the wet abrasion time but by different mechanisms.     

Cationic wood cellulose films with high strength and bacterial anti-adhesive properties

In this work, periodate oxidized birch wood pulp and microfibrillated cellulose (MFC) were cationized using Girard’s reagent T or aminoguanidine. Cationic celluloses were used to obtain films via solvent-casting method, and the effects of the cationization route and the cellulose fiber source on the properties of the films were studied. Thermal and optical properties of the films were measured using differential scanning calorimetry and UV–Vis spectrometry, and the morphology of the films was examined using an optical microscope and a field emission scanning electron microscope. Bacterial anti-adhesive properties of the films were also studied using a modified leaf print method and against Staphylococcus aureus and Escherichia coli. Both cationizing agents exhibited similar reactivity with periodate oxidized celluloses, however, MFC had significantly higher reactivity compared to birch pulp. The films with high tensile strength (39.1–45.3 MPa) and modulus (3.5–7.3 GPa) were obtained from cationized birch pulp, aminoguanidine modification producing a film with slightly better mechanical properties. Modulus of the films was significantly increased (up to 14.0 GPa) when MFC was used as a cellulose fiber source. Compared to the unmodified MFC films, the cationic MFC films were less porous and significantly more transparent; however, they had slightly lower tensile strength values. It was found that aminoguanidine modified celluloses had no culturable bacteria on its surface and also exhibited resistance to microbial degradation, whereas there were culturable bacteria on the surface of Girard’s reagent modified films and they were partially degraded by the bacteria.     

The cationization mechanism study of novel oligo (<Emphasis Type="Italic">p</Emphasis>-phenyleneethynylene)s

Two series of new oligo(p-phenyleneethynylene)s (OPEs) O1-O4 and O5-O8, which have been proven to be one of the chief classes of molecules mainly used as the wires and other potential backbones of molecular electronic devices, have been synthesized by stepwise synthetic approach. The characterization of these oligomers was performed on MALDI TOF MS. Different cationization salts have been applied to investigate the ionization processes of these series of oligomers under MALDI conditions. The experimental results show that these oligomers display a strong tendency to undergo radical cationization and varied ionization efficiency with different cationization agents attributable to their difference in cationic diameters. Furthermore, we found that these two series of oligomers differed in ionization properties because of their different end-groups even when the same cationization agent was used.     

Solvent selection for matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometric analysis of synthetic polymers employing solubility parameters

The principle relating to the selection of a proper matrix, cationization reagent, and solvent for matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) of synthetic polymers is still a topic of research. In this work we focused on the selection of a suitable MALDI solvent. Polystyrene PS7600 and poly(ethylene glycol) PEG4820 were analyzed by MALDI‐TOF MS using various solvents which were selected based on the Hansen solubility parameter system. For polystyrene (PS), dithranol was used as the matrix and silver trifluoroacetate as the cationization reagent whereas, for poly(ethylene glycol) (PEG), the combination of 2,5‐dihydroxybenzoic acid and sodium trifluoroacetate was used for all experiments. When employing solvents which dissolve PS and PEG, reliable MALDI mass spectra were obtained while samples in non‐solvents (solvents which are not able to dissolve the polymer) failed to provide spectra. It seems that the solubility of the matrix and the cationization reagent are less important than the polymer solubility. Copyright © 2010 John Wiley & Sons, Ltd.     

Molecular mass determination of saturated hydrocarbons: reactivity of eta5-cyclopentadienylcobalt ion (CpCo*+) and linear alkanes up to C-30

The present study demonstrates the feasibility of the eta5-cyclopentadienylcobalt ion (CpCo*+) as a suitable cationization reagent for saturated hydrocarbon analysis by mass spectrometry. Ion/molecule reactions of CpCo*+ and three medium chain-length n-alkanes were examined using Fourier-transform ion cyclotron resonance mass spectrometry. Second-order rate constants and reaction efficiencies were determined for the reactions studied. Loss of two hydrogen molecules from the CpCo-alkane ion complex was found to dominate all reactions ( > or = 80%). Furthermore, this dehydrogenation reaction efficiency increases with increasing chain length. These preliminary results suggest that the CpCo*+ ion may be a promising cationization reagent of longer chain saturated hydrocarbons and polyolefins.     

丙烯酰胺与4-乙烯基吡啶共聚物的季胺化及其若干性能

将丙烯酰胺 (AM)与 4 乙烯基吡啶 (4VP)的共聚物 (P(AM co 4VP) )用硫酸二甲酯季铵化 ,制备了系列吡啶季铵盐型阳离子丙烯酰胺共聚物 ,用FTIR、1 H NMR和紫外分光光度法表征了其分子结构与组成 ,并重点研究了其絮凝与缓蚀性 ,考察了阳离子度与分子量对其各种功能的影响 .研究结果表明 ,吡啶季铵盐型阳离子丙烯酰胺共聚物具有优良的絮凝 缓蚀等功能 ,且阳离子度越高 ,性能越好 ,而分子量对其性能亦有显著的影响 .     

TEMPO-mediated oxidation of corncob holocellulose and its influences on paper properties

In this study, the agricultural by-products of corn production (corncobs) were ground into a powder form. Then, the powder was treated with sodium chlorite to remove the lignin, and the remaining holocellulose was optionally modified with 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO)-mediated oxidation. The resulting product was examined using an elemental analysis, along with Fourier transform infrared spectroscopy (FTIR). The effects of the oxidation time and dosages of the TEMPO on the paper’s physical properties were investigated. The results indicated that the TEMPO-mediated oxidized corncob holocellulose had the ability to improve the properties of both paper and recycled paper. When 1.0% oxidized holocellulose was used, the resulting tensile index, burst index, and folding endurance were increased by 4.16%, 8.63%, and 50.71%, respectively, compared with the control paper. The SEM analysis indicated that the bonding between fibers was improved by adding oxidized corncob holocellulose. Compared with the control paper, it was determined that the proportion of mesopore within the fibers increased and the bonding of the C–O bonds increased in the paper with the oxidized corncob holocellulose. The results of this study may potentially provide guidance for the future high value-added application of corncobs as a paper strengthening agent.     

液相还原法制备超细球形镍粉

本文论述了液相还原法直接制备高振实密度球形镍粉的新工艺。采用NiSO_4·5H_2O为原料,利用NaOH调节溶液的pH值并形成Ni(OH)_2,还原剂采用N_2H_4·H_2O,还原过程中加入晶核引发剂及表面活性剂。采用正交实验表安排实验,对影响镍粉振实密度及粒径的因素进行了极差分析。实验数据表明,溶液中镍的初始浓度对产品质量的影响最大,较优工艺组合条件为:初始Ni~(2+)的浓度1.5mol·L~(-1),NaOH用量为理论量的1.1倍,反应温度80℃,表面活性剂用量为每克镍5mg,晶种添加量为还原剂理论用量的0.1％。新工艺可制备振实密度高达3.0以上、质量中位径为1μm的球形镍粉。     

可瓷化硅橡胶材料的研究

研究了一种可瓷化硅橡胶,其特点是在火灾发生时可在金属线外形成瓷化绝缘保护层,600℃的成瓷温度大幅度低于目前文献报道的成瓷温度。实验得到的优化瓷化填料配方为:相对于100份混炼胶,氧化铝10份、硅灰石15份、结构控制剂9份、碳酸锂3份。在此配方条件下,未瓷化硅橡胶的断裂伸长率316%、拉伸强度10.79MPa、体积电阻率134×10~(12)Ω·cm,其在600℃、800℃瓷化后的抗压强度分别为3.47MPa、10.13MPa、体积电阻率≥28×10~(12)Ω·cm,满足电缆用硅橡胶的力学和绝缘要求。经热重分析及SEM分析可知加入瓷化填料后,试样烧蚀重量减少了39.4%,烧蚀残留率大大提高,且成瓷试样结构致密。     

Aftertreatment of Conventional Direct Dyeings of Cotton with a Bis-reactive Cationic Fixing Agent

A bis-reactive cationic fixing agent, ethylenebis[N-(2,3-epoxypropyl)-N,N-dimethylammonium chloride] has been used as an aftertreatment reagent to improve the wash fastness of direct dyes on cotton. The effects of different pH conditions and concentrations on the effectiveness of this cationic fixing agent have been investigated. The results showed that aftertreatment at pH 11 produced dyeings with higher colour strength and better wash fastness than that at pH 7. In addition, the cationic agent at a low concentration was found to be more effective under both neutral and alkaline conditions.     

两性淀粉接枝共聚物在中性抄纸中的应用

为考察两性淀粉与丙烯酰胺接枝共聚及阳离子合成的具有功能化、网络化的多元变性淀粉对纸张的增强效果,采用废纸浆为原料,在中性抄纸条件下,对该多元变性淀粉的增强应用性能进行了研究。结果发现,两性淀粉与丙烯酰胺接枝共聚物(AS-g-PAM)及其阳离子化的衍生物(AS-g-CPAM)比两性淀粉具有更好的增强效果,尤其可大幅度提高纸张的环压强度。与两性淀粉比较,用量为0.5%AS-g-PAM和AS-g-CPAM可分别提高环压指数22%和45%以上,对纸张的抗张指数、耐破度等也比使用两性淀粉有不同程度的提高,同时,AS-g-CPAM在0.05%的低用量时,仍具有较好的增强效果。     

Molecular weight analysis of water‐soluble poly(phenylene ethynylene)s using MALDI‐TOF MS

Molecular weights of seven poly(phenylene ethynylene)‐based water‐soluble conjugated polyelectrolytes (CPEs) obtained through Sonogashira coupling are determined by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS). A standard sample preparation protocol is developed to characterize the seven CPEs using 2,5‐dihydroxybenzoic acid as the matrix (M) and AgTFA as the cationization reagent (CR). High‐quality MALDI mass spectra are obtained at volume mixing ratios (CPE/M/CR) of 5/5/1 for anionic polymers (P1–P4) and 5/50/1 for cationic polymers (P5–P7). Molecular weight, molecular weight distribution, and end‐group information are analyzed. The effects of molecular weight of CPEs on optical and quenching properties are also studied. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2537–2543     

Effect of surface cationization on the conformal deposition of polyelectrolytes over cotton fibers

The effect of surface cationization on the conformal deposition of alternating nanolayers of poly(sodium styrene sulfonate) (PSS) [Kleinfeld E, Ferguson G (1996) Chem Mater 8:1575–1578] and poly(allylamine hydrochloride) (PAH) over cotton fibers is reported. Three different levels of cotton cationization were evaluated. Variations in the cationization degree were achieved by manipulating the ratio of 3-chloro-2-hydroxy propyl trimethyl ammonium to NaOH. Experimental results obtained via Carbon–Hydrogen–Nitrogen–Sulfur (CHNS) elemental analysis and X-ray Photoelectron Spectroscopy (XPS) indicated that the deposition process was not significantly influenced by the degree of cotton cationization. The build up of further polyelectrolyte layers was found to be less sensitive to variations in the cationic character of the substrates once a critical number of alternating layers was deposited.     

Synthesis and physicochemical properties of low-substituted cationic ethers of starch

The kinetics of the formation of cationic starch ethers under the action of 3-chloro-2-hydroxypropyltrimethylammonium chloride is studied in relation to the reactant molar ratio, temperature, and concentration of the starch suspension. Comparative data on how the content of the introduced catoinic groups depends on the origin of native starch are presented. The efficiency of starch cationization and the physicochemical properties of the synthesized samples are examined by chemical analysis, scanning electron microscopy, X-ray diffraction analysis, and thermal gravimetric analysis.     

Effects of nucleating agent 1,3,5-benzenetricarboxylic acid tris(cyclohexylamide) on properties and crystallization behaviors of isotactic polypropylene

Amide derivatives of 1,3,5-benzenetricarboxylic acid are a type of novel nucleating agents for isotactic polypropylene (iPP). Effects of nucleating agent 1,3,5-benzenetricarboxylic acid tris(cyclohexylamide) (BTCA-TCHA) on properties and crystallization behaviors of iPP were investigated and the results were compared with those of iPP nucleated with a highly effective commercial nucleating agent Millad 3988. The results showed that BTCA-TCHA was highly effective and it improved greatly the mechanical and optical properties of iPP and increased crystallization peak temperature of iPP obviously. When the addition concentration of BTCA-TCHA was 0.2 wt.%, tensile strength and flexural modulus of iPP were increased by 9.7 and 12.4 %, respectively, and the haze value of iPP was decreased by 53.5 %. When the cooling rate was 20 °C/min, the crystallization peak temperature of iPP was increased from 114.6 °C of virgin iPP to 126.8 °C. In addition, it was found that the nucleation efficiency of BTCA-TCHA was comparable for that of Millad 3988.     

乙二醇二缩水甘油醚的合成及作为阳离子型紫外光固化稀释剂性能研究

以三氟化硼乙醚络合物为催化剂,以氢氧化钠为成环反应的闭环剂,利用乙二醇和环氧氯丙烷为原料合成了乙二醇二缩水甘油醚.研究了催化剂三氟化硼乙醚络合物用量、环氧氯丙烷和乙二醇摩尔比、氢氧化钠和乙二醇摩尔比,以及成环反应温度这些因素对合成反应的影响.结果表明较好的合成反应条件是:三氟化硼乙醚络合物质量分数为0.40%,环氧氯丙烷和乙二醇较佳摩尔比为2.4:1,氢氧化钠和乙二醇较佳摩尔比为2.2:1,较佳的成环反应温度为30℃.同时,把乙二醇二缩水甘油醚作为稀释剂加入到环氧树脂E-51中,利用三芳基锍鎓六氟锑酸盐作为引发剂,制备了阳离子型紫外光固化涂料,其紫外光固化膜的拉伸强度为46.25MPa,杨氏模量为1487.26MPa,断裂伸长率为6.27%.     

In situ preparation,characterization and performance of magnesium carbonate whiskers/cellulose fibers hybrid paper

Magnesium carbonate whiskers/cellulose fibers hybrid paper was successfully prepared via in situ synthesis process, and the flame retardancy and tensile strength properties were investigated. The effects of magnesium salt type, initial magnesium salt concentration, temperature, time and pH value were also detected. The hybrid paper was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy and thermogravimetry-derivative thermogravimetry techniques, respectively. The results showed that the same whiskers/fibers hybrid paper could be prepared from different magnesium salts. If the pH was above 9.4, hydrated basic magnesium carbonate would be created, which would lead to the decrease of oxygen index (OI). Reaction time had no effect on the OI and tensile strength of the hybrid paper. Under the optimized conditions, the OI of the hybrid paper reached 28 %. The in situ synthesis process was much better than the direct addition process.     

Electrospray droplet impact/secondary ion mass spectrometry (EDI/SIMS) using NaF and AgF as cationization matrices

In our previous paper, it was suggested that metal fluorides may be useful as cationization matrices in Electrospray droplet impact/SIMS. In this work, NaF and AgF were used as the cationization matrices for cyclodextrin (CD), polyethylene glycol (PEG), polystyrene (PS), garlic juice, and sliced raw rice. EDI mass spectra were measured without and with the use of matrices. Enhancement of ion abundances of [M + Na]⁺ for CD and PEG with NaF matrix and that of [M + Ag]⁺ for PS with AgF matrix were observed. However, the addition of matrices was not effective for the cationization of garlic juice and sliced raw rice samples. This may be due to the Coulombic repulsion of the reagent ions of Na⁺ or Ag⁺ with the preformed K⁺ adducts of oligosaccharides already present in the samples. Copyright © 2015 John Wiley & Sons, Ltd.     

Simultaneous crosslinking and cationization of cotton cellulose by using dialdehyde and choline chloride: comparison between the pad-dry-cure and microwave irradiation process

Simultaneous crosslinking and cationization of cotton cellulose were carried out by using two dialdehydes, glyoxal (GO) and glutaraldehyde (GA), along with choline chloride (ChCl). Two heating methods, conventional pad-dry-cure (PDC) and microwave irradiation, were investigated and compared. The results revealed that two aldehyde molecules reacted very differently in the presence of ChCl under two different heating methods. GO reacted predominantly with the cellulose molecule, stimulating the crosslinking reaction and consequently resulting in high wrinkle recovery angle (WRA) values regardless of the heating process. Contrarily, GA favored the reaction with ChCl, allowing high K/S values with acid dye under microwave irradiation. The crosslinked and cationized cotton cellulose was only obtained by treatment with GA and ChCl under the PDC process, resulting in high WRA and K/S values. Characteristics of the treated fabrics were also evaluated by Fourier transform infrared analysis, thermogravimetric analysis, scanning electron microscopy, water of imbibition, and tensile strength test. Additionally, the treatments with GA and ChCl also provided high antimicrobial properties of the cotton celluloses; thereby most bacteria reductions of the specimens were close or equal to 99.9 %. Therefore, economically viable yet ecofriendly crosslinking and cationization of cotton cellulose could be made by treatment with GA and ChCl.     

Frontal polymerization synthesis and characterization of Konjac glucomannan‐graft‐acrylic acid polymers

Konjac glucomannan‐graft‐acrylic acid polymers, used as superabsorbent polymers (SAPs), were synthesized by frontal polymerization (FP). The features of front propagation including front velocity and maximum temperature (T_max) were influenced by the amount of glucomannan, initiator, and environment temperature. The graft copolymer was characterized by FTIR, DSC, and SEM. The amount of crosslinking agent mainly determined the crosslinking degree of SAPs that would affect the water absorbency and microstructure. Water absorbency of SAP was also investigated and most of them displayed high water absorption rate. The aforementioned results allow us to conclude that FP can be considered as a promising method to fabricate SAP for its excellent advantages. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3391–3398, 2009