Efficiency of ultraviolet/ozone treatments in the improvement of the dyeability and light fastness of wool

In this study, we evaluated the effect of ultraviolet/ozone treatments for different times on the characteristics of wool fabrics with respect to wettability, permeability, yellowness index, and weight loss. The beneficial effects of this treatment on dyeability, color parameters, light fastness characteristics, and the change in color difference after exposure of the treated dyed samples to artificial daylight for about 150 h was investigated. The results indicated that the improvement in wetting processes may have been due to to surface modifications; this meant that an increase in the amorphousity of the treated samples, the oxidation of the cystine linkage on the surface of the fabrics, and the formation of free‐radical species encouraged dye penetration and aggregation inside the fiber pores as well as bond formation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3668–3675, 2003     

Biocidal polyester

Polyester fabrics were modified by covalently linking heterocyclic moieties, which could be halogenated, to the surfaces of the polyester fibers. Antimicrobial activity was introduced into the fabrics and fibers by exposure to a source of oxidative chlorine (chlorine bleach) that converted the heterocyclic precursor moieties into N‐chloramine functionalities. The antimicrobial activity could be repeatedly regenerated following its loss on challenge with suspensions of bacteria by further washing with aqueous oxidative chlorine. Biocidal polyester fabrics, fibers, and other materials potentially will be effective in reducing, or eliminating entirely, pathogenic microorganisms and odor‐causing micro‐organisms which directly contact them. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 177–182, 2002     

Durable and regenerable antimicrobial textile materials prepared by a continuous grafting process

A cyclic‐amine monomer, 3‐allyl‐5,5‐dimethylhydantoin (ADMH), was grafted onto various textile materials in a continuous finishing process to prepare durable and regenerable antibacterial textiles. Highly efficient radical grafting polymerizations occurred inside or on the surfaces of fibers with the assistance of different initiators. In the finishing process, particular factors such as types and concentrations of radical initiators, drying, and curing conditions were rather important in effecting the final grafts of ADMH on fabrics and were studied carefully. After exposure to chlorine, the grafted hydantoin structures in the samples could be transformed into N‐halamines, which provided powerful, durable, and regenerable antibacterial activities. The influence of hydrophilic/hydrophobic properties of the fabrics on the antibacterial activities was discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1592–1599, 2002; DOI 10.1002/app.10456     

Electrically conductive textiles by in situ polymerization of aniline

Two methods of obtaining electrically conductive fabrics by in situ polymerization of aniline were compared. Conductive fabrics were prepared by immersing the nylon 6 fabrics in 100% aniline or an aqueous hydrochloride solution of aniline followed by initiating successive polymerization in a separate bath (DPSB) or in a mixed bath (DPMB) of oxidant and dopant solution with aniline. In each case, the polymerization conditions were optimized to obtain the maximum quality of polyaniline (PAn) on the fabrics. The higher conductivity of composite fabrics, whose value reached up to 0.6 × 10⁻¹ s/cm, was obtained by the DPMB process. Moreover, this method induced the least decrease in the degree of crystallinity as compared to the DPSB process. The serviceability of the PAn–nylon 6 composite fabrics was also evaluated. No significant changes in the conductivity were observed after abrading the composite fabrics over 50 cycles and multiple acid and alkali treatment. The stability of conductivity was slightly decreased by less than 1 order after exposure to light for 100 h, but it was significantly decreased after washing with detergent. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2094–2101, 1999     

Effect of EDTA concentration on the physical and optical properties of Cds thin films

Application of ethylenediamine tetraacetic acid (EDTA) in the chemical bath solution to enhance the physical and optical properties of chemical bath deposited CdS film was realised. The observed beneficial effect on the crystallisation of CdS crystallites in the bath solution followed by deposition on glass substrates reduces the amorphousity and enhances the crystallinity of the film. The optical transparency of the film attains a maximum of 80% over the wavelength range of 650–1100 nm for the film deposited from EDTA‐added solution having the concentration of 0.006 mol/L. Also, the observed intensity of the characteristic photoluminescence emission was found to be dependent on the concentration of EDTA in the bath solution. © 2011 Canadian Society for Chemical Engineering     

Chemical modification of nylon 6 and polyester fabrics by ozone‐gas treatment

In a previous article, we reported on the ozone‐gas treatment of wool and silk fabrics in relation to the gas‐phase processing of textile fabrics. The treatment incorporated an oxygen element into the fiber surface and contributed to an increase in water penetration into the fabric. In this study, nylon 6 and polyester fabrics were treated with ozone gas in the same way as that of the wool and silk fabrics. The treatment incorporated much more oxygen into the fiber surface in the form of ? COH and ? COOH, as shown by electron spectroscopy for chemical analysis. Water penetration increased considerably with treatment, and the apparent dyeing rate and equilibrium dye uptake were also improved, especially for the polyester fabric, despite an increase in the crystallinity. Therefore, it seemed that the treatment brought about a change not only in the fiber surface but also in the internal structure of the fibers (the crystalline and amorphous regions) with regard to the dyeing behavior. Further, the mechanical characteristics of the ozone‐gas‐treated polyester and nylon 6 fabrics were measured with a Kawabata evaluation system apparatus. The shearing modulus and hysteresis widths increased with treatment, especially for the polyester fabric. Therefore, it was clear that the treatment caused a change in the fabric hand to crisp. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1344–1348, 2006     

Possible phosphorus‐bromine synergy in polyester‐cotton fabrics treated with tetrabromobisphenol‐A and diammonium phosphate

Polyester/cotton fabrics were treated with tetrabromobisphenol‐A (TBBA)/epichlorohydrin (EPI) aqueous solution, followed by being treated with diammonium phosphate (DAP)/urea solution. The optimum mole ratio of EPI to TBBA was determined. The synergism of TBBA and DAP was found to operate on the treated fabrics. The maximal synergism was obtained when the bath concentration of TBBA was equal to that of DAP. The mechanism of flame‐retardancy was analyzed by thermogravimetry and residue number. The flame‐retardancy of the polyester/cotton fabrics treated with TBBA/DAP was found operative mainly in the condensed‐phase mechanism. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 172–177, 2002; DOI 10.1002/app.10292     

Plasma-induced adhesion improvement of cotton/polypropylene-laminated fabrics

In this study, improvement in the adhesion strength of plasma-pretreated and laminated cotton/polypropylene (PP) fabrics using acrylic-based adhesive was investigated. Low-temperature, low-pressure oxygen plasma was utilized for surface modification of cotton/PP-laminated fabrics. Water absorption time was measured on plasma-treated cotton fabrics at different plasma power and treatment time conditions. The plasma conditions providing the fastest liquid absorption on the surface were selected and applied during plasma pretreatments. Surface wettability increased with increasing plasma power and plasma exposure time. Plasma-induced surface morphology changes were observed via Scanning Electron Microscope (SEM) images. X-ray Photoelectron Spectroscopy (XPS) analysis showed that oxygen content on the surface increased with plasma treatment, which contributed to the surface polarity and hydrophilicity. Peel bond strength results of untreated and plasma-treated samples were analyzed to determine the effect of plasma pretreatment process. Adhesion strength values of laminated samples, before washing and after 40 wash cycles, were determined by peel bond strength tests. Before washing, adhesion strength of plasma pre-treated, laminated samples was 28–60% higher than that of untreated laminated fabrics. After 40 wash cycles, adhesion strength of plasma pre-treated and laminated samples was about 40–69% higher than the untreated laminated fabrics. Peel bond strength values decreased with the increased number of wash cycles. Plasma pretreatment enhanced both the adhesion strength and washing resistance of laminated samples.     

Biodegradability of cellulose fabrics

Biodegradability of cellulose fabrics was evaluated by use of a soil burial test, an activated sewage sludge test, and an enzyme hydrolysis. Surface changes after biodegradation were observed by optical microscopy. From X‐ray diffraction analysis (XRD), changes in the crystallinities and the internal structures as a result of degradation were also investigated. It was shown that biodegradability decreased in the following order: rayon > cotton ? acetate. Rayon fibers, which have a low crystallinity and a low degree of orientation, showed the highest biodegradability in most cases. However, in spite of its low crystallinity, acetate fibers exhibited very low biodegradability, probably because of the presence of hydrophobic groups in its structure. On the other hand, linen showed an inconsistent behavior in that it had the highest biodegradability in the soil burial test, but a lower biodegradability than that of cotton in the activated sewage sludge test. XRD analysis revealed that there was a slight increase in the crystallinity of linen, cotton, and rayon fabrics at the initial stage, but a continuous decrease thereafter. From the correlation analysis, it was revealed that the biodegradability of cellulose fabrics was closely related to the moisture regain of the fibers, which reflects the hydrophilicity and internal structure of the fibers at the same time. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 248–253, 2004     

Basic dyeable polyester: a new approach using a VUV excimer lamp

Surface treatment of polyester fabric was carried out using a vacuum ultraviolet (VUV) excimer lamp. The hydrophilicity of the polyester fabric was significantly improved by surface modification, as indicated by the decrease in wetting time and wicking time. This approach can be used to create added value for polyester fabric, which otherwise suffers from low hydrophilicity. Further changes on irradiation were characterised by atomic force microscopy and the crystallinity and tensile strength of the samples were also tested. Basic dyeability of the microdenier polyester fabric was seen to improve greatly on exposure to the excimer lamp, followed by grafting with acrylic acid. The effects were observed to increase with an increase in irradiation time. The best effect was obtained for irradiation time of 10 min. These enhanced properties were accompanied by an insignificant loss in crystallinity and tensile strength of treated fabrics.     

Degradation of PLA and PLA in composites with triacetin and buriti fiber after 600 days in a simulated marine environment

Poly(lactic acid) (PLA), the polymer object of this study, degrades by a biotic process after an abiotic hydrolysis process. Its degradation was evaluated after 600 days of exposure in a simulated marine environment (SME), as buriti fiber‐reinforced composites having triacetin as coupling agent. Composites were obtained by extrusion and films were produced by compression molding. After between 60 and 600 days of exposure, PLA had a weight loss of 2.5%, PLA/T of 1.5%, and 10–12% of weight loss for PLA/B and PLA/B/T, respectively. PLA intercalates reduction, increase, and decrease of its crystallinity attributed to hydrolysis (up to 15 days), impairment of amorphous segments (45 days), and loss of integrity of the matrix (100–600 days), respectively. In the PLA/T composites, triacetin inhibited the diatom colonization process, having its crystallinity values increased after nearly 100 days of exposure with subsequent reduction. For samples with buriti fiber, changes in crystallinity were attributed to absorption of water and exposure of matrix amorphous segments. PLA degradation in a SME is evidently favored by the use of natural fibers since they make easier water access to the matrix and colonization by the protists group, diatoms, showing that the polymer can have reduced post‐use shelf life as composites, with benefits while in use and at the same time post‐use environmental benefits. Triacetin inhibits PLA colonization and degradation up to 45 days after exposure, after which it no longer influences the degradation process. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43290.     

Effect of in situ deposition of calcium carbonate in cotton fiber on its mechanical properties

In this study, in order to improve mechanical properties of cotton fabrics, nano-micro sized calcium carbonate (CaCO₃) was deposited in situ on cotton fabrics. The mechanical properties, surface morphology, crystalline index, infrared spectrum, thermal property, and wettability of the deposited fabrics were measured and discussed. The results showed that the breaking strength of cotton fabric increased by about 10% after in situ deposition of nano-micro calcium carbonate. After ultrasonic washing, the strength of cotton fabric deposited CaCO₃ was still increased by about 10%. The crystallinity of the cotton fabric deposited with calcium carbonate increased from 76% to 84%. The hydrogen bond between cellulose molecules and calcium carbonate was confirmed by infrared spectroscopy. The hydrophilicity and thermal properties of cotton fabric were not significantly influenced by calcium carbonate deposition. This provides a new idea for improving the mechanical properties of cotton fabric.     

Surface modification of polyester and polyamide fabrics by low frequency plasma polymerization of acrylic acid

In this study, the surface characteristics of polyester and polyamide fabrics were changed by plasma polymerization technique utilizing acrylic acid as precursor. This monomer was used to produce hydrophilic materials with extended absorbency. The hydrophilicity, total wrinkle recovery angle (WRA°) and breaking strength of the fabrics were determined prior and after plasma polymerization treatment. The modification of surfaces was carried out at low pressure (<100 Pa) and low temperature (<50°C) plasma conditions. The effects of exposure time and discharge power parameters were optimized by comparing properties of the fabrics before and after plasma polymerization treatments. It was shown that two sides of polyester fabric samples were treated equally and homogeneously in plasma reactor. For polyester fabrics, the minimum wetting time, 0.5 s, was observed at two plasma processing parameters of 10 W–45 min and 10 W–20 min, where untreated fabric has a wetting time of 6 s. For polyester fabrics, the maximum value was obtained at 60 W–5 min with the wrinkle recovery angle of 306° where the untreated fabric has 290°. The optimum plasma conditions for polyamide fabrics were determined as 30 W–45 min where 2 s wetting time was observed. Wrinkle recovery angle of untreated polyamide fabric was 264°. In this study, after plasma polymerization of acrylic acid, wrinkle recovery angle values were increased by 13%. No significant change was observed in breaking strength of both fabrics after plasma treatment. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2318–2322, 2007     

Flame-retardant viscose–polyester fabrics

For many purposes the natural-synthetic fiber-blend fabrics are more suitable than pure natural or synthetic products. It is often possible to obtain a maximum in clothing and textile technical properties by compensating the defects of one fiber by using an other totally different fiber. Many problems, however, have arisen in the production of flame-retardent fabrics because the use of synthetic fibers often makes the fire retardancy less effective. In our 2-year research project different fire-retardant (FR) viscose–polyesters fabrics were prapared at first in the laboratory scale. The natural type raw materials were Modal Prima viscose and normal FR–viscose cotton type staple fibers. The synthetic raw materials were FR–polyesters of the same type with two different flame retardants. Test fabrics were knitted in the laboratory by using seven blended yarns in the ratios 100/0, 80/20, 65/35, and 50/50 and vice versa. Cotton type PVC–fiber was also used in some experiments. All these test fabrics were also finished chemically by using normal crease-resistant (DMU, DMEU, DMDHEU, and TMM) and flameretardant (N,-methylolphosphonopropionamide and THPC) finishing chemicals. The textile and fire-retardant properties of the original and finished fabrics were estimated by using addon, tensile strength, LOI-value, and vertical flame test determinations. The mechanism of flame retardancy was also studied with DSC technique, P- and N-analysis and char investigations. The test results of viscose/polyester studies were compared with the results of cotton/polyester studies. After laboratory studies the best methods for FR–viscose/polyester fabric production were chosen, and the fabrics were manufactured. The fabrics were home-washed 20–50 times, and the textile and FR-properties were determined after each 10 washings. These results were again compared with results of cotton/polyester fabrics.     

Effect of winding speed on the structure and properties of as‐spun poly(trimethylene 2,6‐naphthalenedicarboxylate) fibers as compared to poly(ethylene terephthalate) fibers

We present a comparative study of melt spinning of poly(trimethylene 2,6‐naphthalenedicarboxylate) (PTN) and poly(ethylene terephthalate) (PET) fibers with respect to the effect of winding speed (2000–6000 m/min): Structural changes were followed by X‐ray analysis, calorimetry, and measurements of density, boiling water shrinkage, and birefringence. As‐spun PTN fibers exhibited a low degree of crystallinity at relatively low speeds (< 2000 m/min). An increase in winding speed up to 6000 m/min only resulted in a minor enhancement of crystallinity and orientation. The small change of structural parameters accounted for the fact that tenacity and modulus did not rise significantly with increasing winding speed, contrary to the PET fibers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2489–2497, 2002     

Mechanical,thermal and degradation properties of jute fabric – reinforced polypropylene composites: Effect of potassium permanganate as oxidizing agent

Mechanical properties of jute fabrics‐reinforced polypropylene composites were measured with reference to fiber loading and found highest at 45% by the weight of jute fabrics. Jute fabrics were treated with potassium permanganate in acid (oxalic acid and sulphuric acid) and alkaline (KOH) media in order to investigate the oxidizing effect on the properties of the composites. Solutions of oxalic acid, sulphuric acid, and KOH were prepared in water as 1.0–10.0% w/v, 0.1–2.0% v/v, and 1.0–10.0% w/v, respectively, where percentage of KMnO4 was maintained at 0.01% w/v. Among the treatments, 5.0% oxalic acid treated jute composite showed better mechanical performance. Thermogravimetric (TG/DTG) data of PP, jute fabrics and composites showed that thermal degradation temperatures of composites shifted to higher temperature regions compared to PP or jute fabrics. The treatment of jute fabrics improves thermal stability of the composites. Treated jute composites were found less degradable in soil, water and simulated weathering conditions and also found less water sensible compared to control composite (45% w/w jute fabrics). POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers     

Effect of morphology on barrier properties of poly(ethylene terephthalate)

The effects of morphology on the barrier properties of poly(ethylene terephthalate) (PET) have been investigated. Various levels of crystallinity can be developed in PET as a result of thermal exposure, orientation, and heat setting. The morphologies of the crystalline phase are affected by the conditions of their formation. As a result of morphological differences, samples with equivalent levels of crystallinity have been found to exhibit different oxygen barrier properties. These differences are most apparent at low and intermediate levels of crystallinity. For thermally crystallized systems, at the same crystalline content, increasing superstructure size in the crystalline phase leads to greater tortuosity for the permeant molecules, resulting in lower permeability. For stretched and heat set PET, transport properties can be correlated with birefringence as well as overall orientation, measured in terms of fraction of molecules in the trans or extended chain conformation. At high levels of crystallinity, where the spherulites become volume filling, permeation takes place primarily through the interlamellar regions of the crystalline phase and is controlled by level of crystallinity, independent of the mode of crystallization. The barrier properties of PET, before spherulitic impingement occurs, are governed by the size and number of spherulites as well as by the amorphous orientation present in non‐crystalline regions. POLYM. ENG. SCI., 45:400–409, 2005. © 2005 Society of Plastics Engineers     

The oxidative degradation of styrenic copolymers: A comparison of photoproducts formation under natural and accelerated conditions

Natural and accelerated weathering of polystyrene and high‐impact polystyrene were carried out in the present investigation. The structural changes in the polymer samples were characterized by using FTIR spectroscopy, tensile strength testing, and SEM spectroscopy. The natural exposure was conducted throughout the year. Rates of photooxidation were determined by measuring the evaluation in hydroxyl and carbonyl regions. The surface deterioration was revealed from SEM micrographs. The drop in tensile strength was also monitored. A correlation between natural and artificial weathering was considered for lifetime prediction in a short exposure time. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1676–1682, 2002     

Comparison of thermal protective performance of aluminized fabrics of basalt fiber and glass fiber

Rapid progress has been made in the field of fire protection during the past few decades, nevertheless, the development of fire protective clothing with prolonged durability has always been a matter for public attention. In order to prevent or minimize skin burn damage resulting from flashover, a kind of thermal protective composite fabric, the surface of which is aluminized, has been upgraded and developed. Using the UV–Vis–NIR (ultraviolet–visible–near infrared) spectrophotometer, the thermal radiation protective performance of aluminized fabrics made of basalt fiber and glass fiber were evaluated and compared. The aluminized fabrics and the substrate fabrics used were exposed to a fire environment generated by burning liquified gas for a few minutes, aiming at evaluating the protective effect of the aluminum coating and characterizing the thermal insulating performance. The results showed that the spectral reflectance of aluminized fabrics present obvious differences over a wide range of wavelengths, perhaps due to the different yarn parameters and weave structure. The fire exposure experiment indicated that the aluminized fabric of basalt fiber had better thermal protective performance than the substrate fabrics. Although the thermal insulating performance of aluminized fabrics is insufficient to provide enough time for people to focus on his/her job, the aluminized fabrics exhibit great potential application in the fields of firefighting and military. Copyright © 2010 John Wiley & Sons, Ltd.     

Surface modification of textiles by glow discharge technique: Part II: Low frequency plasma treatment of wool fabrics with acrylic acid

In this study, wool fibers are modified by low frequency plasma polymerization of acrylic acid regarding to its' hydrophobic character due to cuticular cells at their surfaces. Variables of the plasma glow discharge processes were power (40–100 W) and exposure time (5–45 min). The effect of plasma modification in the performance properties of wool were investigated on the basis of hydrophilicity of wool, average wrinkle recovery angle, and breaking strength. The surface chemical structures of fabrics were examined with x‐ray photoelectron spectroscopy. The hydrophobic wool fabric became hydrophilic after all plasma treatments except one (40W–5 min). Average wrinkle recovery angle of the treated fabrics were between 157 and 178°, while that of untreated fabric was 180°. The treated fabrics had a little bit lower angles according to the untreated fabric. However, even the lowest value as 157° means that the fabric has a good crease resistance property. The breaking strengths of fabrics were increased up to 26% after the plasma treatments. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010