Sławomir Sztajnowski

Chitin filaments from dibutyrylchitin precursor: Fine structure and physical and physicochemical properties

Chitin filaments obtained after alkaline hydrolysis of dibutyrylchitin ( DBCH ) precursor filaments were investigated. The morphological structure, fine structure, and selected physical and physicochemical properties were studied. The studies of morphological structure included the assessment of the cross-section profile, the length and developing index of the contour line of the cross sections, the appearance of spherolitical crystalline aggregations, and the existence of skin-core building. The appraisal of the fine structure comprised the recognition of the lattice crystal system and the parameters of the unit cell, the crystallinity degree and average lateral crystallite sizes, and the crystalline and amorphous orientation. The characterization of physical properties included the appraisal of density, mechanical, thermal, electrical, and optical properties. In the area of physicochemical properties, swelling and dyeability were examined.

Effect of processing variables on the thermal and physical properties of poly(L-lactide) spun bond fabrics

In this paper, the influence of the take-up velocity (Vt–u) of fibers on the molecular ordering and ά – α form transition of polylactide (PLA) non-woven fabrics during their manufacturing by spun-bonding is described. Non-woven samples were studied by wide-angle X-ray diffraction, differential scanning calorimetry and Fourier transform infrared spectroscopy. In addition, the physical and mechanical properties of the non-woven fabrics were determined. The results are discussed in terms of the structural changes of the PLA and the meso-phase content during the spun-bonded non-woven fabric forming process. This technological process includes preliminary molecular ordering of the PLA fibers in a downstream spinning block and crystallization on a calender system at a temperature higher than the glass transition. The molecular ordering of the investigated PLA fabric samples under different technological conditions was observed as follows: creation of the meso-phase and a disorder-to-order phase transition (ά to α form) during heating to approximately 110℃ and an increase in the degree of crystallinity for take-up velocities higher than 1400 m/min. The structural changes of the PLA explain the observed changes in the physical and mechanical properties of the non-woven fabrics obtained under different technological conditions.

IR Spectroscopy as a Possible Method of Analysing Fibre Structures and Their Changes Under Various Impacts

Infrared absorption spectroscopy, broadly applied to analyse polymer structures (within the spectral wavenumber range of 400-4000 cm-1), is also employed as a method of studying fibre structures and their changes. This is one of the instrumental methods commonly applied in Fibre Physics for the purpose of qualitative and quantitative analyses of fibre orientation, studies of fibre crystalline structure, and selective evaluation of the structure of fibre surface layers, as well as the effects of superficial and volumetric modification of fibre structures.

Ozone treatment of jute fibers

Oxidation of cellulosic materials is required in many fields such as textile processing, natural fiber composites, medical utilization, and so on. The present study was designed to explore the possibility of ozone treatment as a greener oxidation process for jute fibers. Ozone gas was used for the treatment of waste jute fibers for different time periods in a humid atmosphere. Several characterization techniques, namely physical appearance, fiber mechanical properties, the copper number, Fourier transform infrared spectroscopy, wide-angle X-ray diffraction, scanning electron microscopy, moisture regain percentage and lightness values (L), were used to assess the effect of treatment on jute fibers. Results showed that fiber tensile properties weaken gradually as a function of treatment time, and surface functional groups alter accordingly. Changes in crystallinity after ozone treatment were also observed. Physically the fiber bundles were split into brittle single fibers, and the L value increased from a brownish shade to lighter color.

Molecular and Supramolecular Changes in Polybutylene Succinate (PBS) and Polybutylene Succinate Adipate (PBSA) Copolymer during Degradation in Various Environmental Conditions

In this paper, the influence of the various degradation conditions, on the molecular and supramolecular structure of polybutylene succinate (PBS) and polybutylene succinate adipate (PBSA) copolymer during degradation is described. The experiment was carried out by the use of injection molded samples and normalized conditions of biodegradation in soil, composting and artificial weathering. Materials were studied by size-exclusion chromatography (SEC) coupled with multiangle laser light scattering (MALLS) detection and wide-angle X-ray diffraction (WAXD). Additionally, the physical and mechanical properties of the samples were determined. The performed experiments clearly show difference impacts of the selected degradation conditions on the macroscopic, supramolecular and molecular parameters of the studied aliphatic polyesters. The structural changes in PBS and PBSA explain the observed changes in the physical and mechanical properties of the obtained injection molded samples.

Influence of the homehold composting conditions on the structural changes of polylactide spun-bonded nonwovens during degradation

In this study, the influence of homehold composting conditions on the molecular and supramolecular structure of polylactide (PLA) in the form of spun-bonded nonwovens was investigated. Nonwoven samples were studied using size-exclusion chromatography coupled with multiangle laser light scattering detection, wide-angle X-ray diffraction, differential scanning calorimetry and Fourier transform infrared spectroscopy. In addition, the physical and mechanical properties of the nonwovens before and after composting were determined. The results show the varying degree of influence of the prepared compost mixtures of soil with common horticultural additives, such as chalk, commercially available agents, cow manure and chicken litter, on the molecular and supramolecular structure of PLA and its degradation rate. The obtained experiment explained which popular homehold agent had the strongest affect on the PLA nonwoven dedicated for agriculture use in the first period of season composting (first 6 months).

Structural Changes in Fibrous Ballistic Materials During PACVD Modification

During PACVD Modification. FIBRES & TEXTILES in Eastern Europe 2015; 23, 6(114): 102-115. DOI: 10.5604/12303666.1167426 102 Researches focused on improving the adhesion of UHMWPE fibres with resin or low-molecular polyethylene forming the destination matrix of the final ballistic material, inter alia by increasing the surface energy. This enables better and more durable blending of modified fibres with the matrix material [4 12]. The effect of plasma assisted chemical vapour deposition (PACVD) polymer deposition onto textile ballistic materials on the physicalmechanical behaviour was described in detail in [4, 13]. ,5,6,7,8,9,10,11,12 The aim of the research was to optimise PACVD modification of two types of unpurified technical textile materials: p-aramid fabric and UHMPWE fibrous materials, to directly obtain a functionalized surface with a highly reproductive deposited polymer.

THE INFLUENCE OF PET FIBRES SURFACE ENZYMATIC MODIFICATION ON THE SELECTED PROPERTIES

Abstract The effect of changes in the surface structure of glossy polyester filaments from poly(ethylene terephthalate) in terms of its micro-topography, molecular and supermolecular structure of the fibre surface layers on selected fibre surface and volumetric properties has been assessed. The performed tests and measurements have shown that the change in the general surface characteristics of PET fibres (micro-topography and hydrophilicity) results in very beneficial changes in both their volumetric (dyeability) and surface properties (wettability, pilling, oil-soil removal and electric properties).

Structural Changes in the PACVD -Modified Para-Aramid, Ballistic Textiles During the Accelerated Ageing

The process of textile modification using Plasma Assisted Chemical Vapour Deposition (PACVD) results in significant changes in surface properties with high effectivity. However, the main problem of the above-mentioned modification is to obtain a stable modification effect during standard use and storage. The aim of the study was to determine the stability of structural properties of PACVD-modified para-aramid ballistic woven fabrics during accelerated ageing using temperature or simultaneously temperature and humidity as the accelerated ageing factors. For identification of potential changes in the textile surface modified by PACVD with deposition of the polymer formed based on tetradecafluorohexane, the ATR-FTIR and SEM/EDS techniques were applied. The PACVD-modified textiles showed insignificant changes in structural properties after accelerated ageing using the above-mentioned ageing factors. This confirms the stability of the PACVD-resulted modification during simulated conditions of standard use.

Structural Changes in Plasma Assisted Chemical Vapour Deposition-Modified Ultra-high Molecular Weight Polyethylene, Ballistic Textiles During Accelerated Ageing

The aim of this study was to compare the susceptibility of the plasma assisted chemical vapour deposition (PACVD) surface modification of ultra-high molecular weight polyethylene (UHMWPE) fibrous composite to conditions of use and storing simulated by accelerated aging. Aspects of heksametylodisiloksan (HMDSO) implementation as donor for deposited during PACVD modification nanolayer as well as the selection of a new textile carrier were discussed. For the identification of potential changes in PACVD modified UHMWPE, with, the Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) and Scanning Electron Microscopy with X-ray microanalysis (SEM/EDS) techniques were applied. The PACVD surface modification of UHMWPE showed insignificant changes in structural properties after using temperature or simultaneously temperature and humidity ageing factors. The process of accelerated ageing confirmed the time-stable presence of silicon contained in the polymer layer in both cases: when temperature or simultaneously temperature and humidity were used as accelerated aging factors. No significant changes in the morphology nor topography of the fibrous materials tested were found, subjected or not to the process of PACVD modification using the HMDSO as a substrate for the surfacedeposited polymer.