Drago Katović

Polycarboxylic acids as non-formaldehyde anti-swelling agents for wood

Abstract Wood specimens of fir (Abies alba Mill) and beech (Fagus sylvatica L.) were chemically modified using polycarboxylic acids (PCA), cured by convection heating or microwave treatment and analyzed by HPLC. A new non-formaldehyde cross-linking system was composed of citric acid (CA) and 1,2,3,4-butanetetracarboxylic acid (BTCA), which are representative polycarboxylic acids (PCAs). These reagents require phosphono-based catalysts, so a sodium hypophosphite (SHP) catalyst was used in this study. The effects of PCA treatment were compared with a previously introduced 1,3-dimethylol 4,5-dihydroxy ethylene urea (DMDHEU) treatment. The dimensional stability of the modified wood was determined in terms of the anti-swelling efficiency (ASE) using the water soak/oven dry method. The results revealed an improvement in ASE for wood modified with PCA compared to modification with DMDHEU. Qualitative and quantitative determinations of bound acids were performed by HPLC. Further intensification of the wood modification process and an increase in the quality of wood-based materials were achieved using microwave treatment. Among other benefits, the formation of cross-links between the wood and the reagent components led to an improvement in the tensile strength retention, particularly in combination with the microwave treatment.

Influence of Microwaves on Nonformaldehyde DP Finished Dyed Cotton Fabrics

An alternative approach to formaldehyde-releasing conventional N-methylol com pounds is based on the use of nonformaldehyde durable press polycarboxlic acid (PCA) finishing agents. Another alternative approach, investigated here, is using microwave energy to impart durable crease resistance to dyed cotton fabric. The bifunctional dyes C.I. Reactive Red 195, C.I. Reactive Yellow 145, and C.I. Reactive Blue 221 are used in the study, and the isocratic HPLC method is employed to quantify the PCA reacted with the cellulosic material for two different curing procedures. Shade change evaluation reveals that microwave curing has a greater influence on the dE values than conventional curing. In all other aspects, primarily wrinkle recovery and deformation resistance, microwave curing offers much better results.

The Effect of Microwave Drying on Warp Sizing

The paper describes our research of microwave usage in drying the size pick-up. An analysis of three different drying processes in relation to physical-mechanical properties of sized yarn has been carried out. Under the same sizing conditions, but different drying methods, the following parameters were determined: breaking force, elongation at break, abrasion resistance and yarn hairiness. The application of microwave drying method for warp sizing showed to be equally good, or even better in some cases, compared to the conduct and convection drying methods.

Spanish Broom (Spartium junceum L.)—History and Perspective

The Spanish Broom (Spartium junceum L.) plant is almost a forgotten textile raw material. In this paper a review of procedures practiced in the past and nowadays for obtaining fibers from this plant is presented. New discoveries about its use as a component of special composite fibers as well as its probable benefits for the households of poorer limestone areas are discussed. Some chemical and physical properties of the fibers extracted from local plants are also reported.

Microwaves in Chemical Finishing of Textiles

The esterification involved in durable press (DP) finishing is one among several chemical reactions that can be improved by microwave radiation. Cotton material is usually esterified with modified 1,3 dimethylol 4,5 dihydroxyethylene urea (DMDHEU). In this study, a novel microwave planar device was used for simultaneous drying and curing processes. The device was constructed at the Department of Textile Chemistry and Material Testing of Faculty of Textile Technology and it is based on a magnetron-fed travelling wave applicator with meandered waveguide. The experimental results showed that microwave-assisted textile finishing yields better results than conventional curing at tenter frame. Noticeable improvements were obtained in wrinkle recovery resistance and tensile strength reduction. In addition, the influence of microwaves on formaldehyde release was investigated in order to decrease formaldehyde emission from textile material. Several different experimental methods were used in order to identify a mechanism of formaldehyde release

Determination of Iron and Copper in Textile Materials by Anodic Stripping Voltametry

Heavy metals at low concentrations can have a damaging effect in chemical and optical bleaching of textile materials. The application of anodic stripping voltametry for determining copper and iron in textile materials is described. The preparation of the samples of cotton, wool, polyester, polyamide, and polyacrylics, and procedures for determining Cu and Fe in these materials are reported.

SEM Characterisation of the Cellulose Material Treated with Polycarboxylic Acid and Zeolite Nanoparticles

Coating of zeolite nanoparticles, previously dispersed in Polycarboxylic acid (PCA) solution, on cellulose textile surface has several advanced technological applications. One of the possible usages is for the Durable Press finishing enabling simultaneous enhanced antimicrobial or flame retardant properties. In this study, one of the polycarboxylic acid crosslinking agents, Citric acid (CA) is used to coat cotton fabric in the presence of synthesized zeolite applied as a catalyst. Cotton fabric samples were padded with a suspension containing zeolite powder in aqueous solution of CA crosslinking agent. Drying and curing of coated samples was performed at different curing conditions, either in a microwave oven or in conventional dryer. Scanning electron microscope (SEM) is used to characterize the surface morphology and confirm bonding of zeolite particles to cellulose fibers. Further characterization of coated surface is performed by attenuated total reflectance (ATR) Fourier transform infrared (FT-IR) spectroscopy while the effects of microwave irradiation on zeolite nanoparticles bonding is estimated by thermogravimetric analysis.

Microbial barrier properties of healthcare professional uniforms

In this study, the microbial barrier properties of textiles for two bacterial endospores were investigated. The reusable hospital textiles (PET/cotton and Tencel®) most commonly recommended for the manufacture of healthcare professional uniforms were tested for microorganism permeability. The three-layer textile laminate PET/PU/PET, which meets the European standards for surgical drapes EN 13795, was used as the reference material in this study. The microbial barrier properties of PET/cotton, Tencel®, PET/PU/PET, and corresponding seams were tested after 1, 10, 20, 30 and 50 washing-and-sterilization cycles. Washing and sterilization were performed by hospital laundry services under strict and controlled conditions. The testing of dry textile materials was conducted under newly developed methods. The most resistant forms of microorganisms of apathogenic bacterial endospores of the Bacillus genus Geobacillus stearothermophilus and Bacillus atrophaeus were used for investigating the microbial barrier permeability of textiles. This research is the first to investigate the permeability of these microorganisms in dry conditions. Additionally, the microbial barrier properties of the seams of these textiles were investigated. Regression analyses were performed and the effects of the seams on microorganism permeability were determined. It can be concluded that the two most commonly used seam types for the manufacture of healthcare uniforms do not have a significant influence on microbial barrier efficacy; however, the seam type 1.01.05/504.504.301 is more suitable for the manufacture of healthcare professional uniforms.

Physicochemical characterization of the multiuse medical textiles in surgery and as packaging material in medical sterilization

Abstract This work investigates changes in the physicochemical properties of dry multiuse medical textiles used in surgery and as packaging material in sterilization after 0, 1, 10, 20, 30, and 50 washing and sterilization cycles in real hospital conditions of the Clinical-Hospital Centre in Zagreb. Scanning electronic microscope (SEM) was used to perform morphological characterization. Physicochemical characterization and the resulting changes in the medical textiles were monitored using Fourier transform infrared (FT-IR) spectrometer. The change in the mass of the medical textiles as a results of temperature was determined by thermogravimetric (TG) analysis. Furthermore, structural characteristics based on the changes that resulted during the washing and sterilization processes are provided. The conclusion of the conducted research on the changes in the properties of multiuse medical textiles (Cotton/PES, Tencel®, and three-layer PES/PU/PES textile laminate) in real hospital conditions is that the medical textiles do manage to preserve properties after continuous use and it is safe to use them up to 50 washing and sterilization cycles.

TENCEL with a Microbial Barrier for Medical Bras

The goal of the research was to determine the properties of the microbial barrier TENCEL knitted fabrics intended for medical bras. The samples were tested according to a new method developed in the earlier research by the same authors. The most resistant forms of microorganisms of a pathogenic bacterial endospore of the Bacilllus genus were used to investigate microbial barrier permeability. Based on the samples tested and their characteristics, medical bra construction was developed with the aim of reducing irritation for the body part that underwent surgery. The data on the forms and measures were obtained using a 3D body scanner.