Proceedings Volume 3095

X-Ray Investigations of Polymer Structures

Andrzej Wlochowicz, Jaroslaw Janicki, Czeslaw Slusarczyk
cover
Proceedings Volume 3095

X-Ray Investigations of Polymer Structures

Andrzej Wlochowicz, Jaroslaw Janicki, Czeslaw Slusarczyk
View the digital version of this volume at SPIE Digital Libarary.

Volume Details

Date Published: 18 February 1997
Contents: 3 Sessions, 22 Papers, 0 Presentations
Conference: X-Ray Investigations of Polymer Structures 1996
Volume Number: 3095

Table of Contents

icon_mobile_dropdown

Table of Contents

All links to SPIE Proceedings will open in the SPIE Digital Library. external link icon
View Session icon_mobile_dropdown
  • Invited Papers on Basic Research Trends Using X-Ray Scattering Methods in Polymer Science and Technology
  • Polymer and X-Ray Scattering Theories and Practice
  • Particles and Extrudates, Aggregation and Gelation
Invited Papers on Basic Research Trends Using X-Ray Scattering Methods in Polymer Science and Technology
icon_mobile_dropdown
Is progress introducing new polymeric architectures and systems followed by research and development of scattering techniques?
Marian Kryszewski
The general remarks on material structure investigation and preparation of hierarchical polymer structures and properties are characterized. The application of small angle X ray (SAXS) and small angle neutron scattering (SANS) are discussed particularly for selected problems of polymer science: molecular weight determination and surface and interface studies are described. These techniques are briefly compared with reflectometry and other known modern methods of surface and interface investigations. It is shown that the state of art of scattering techniques is adequate to today's needs. There are still many problems which are intense experimental and theoretical progress emerging from the development in preparation, processing and application of polymers. After general remarks on material structure and its investigation, some aspects of preparation and hierarchical structure formation in polymers are given. Next selected problems of new polymeric architectures and systems as seen by scattering techniques, including molecular mass and surfaces/interfaces, are discussed. Final remarks, conclusion, acknowledgements, and a selection of representative references end the paper.
Small-angle x-ray scattering under extreme conditions of temperature, pressure, and time
Peter Laggner, Manfred Kriechbaum
The mechanism and kinetics of phospholipid phase transitions--induced by temperature jumps or pressure jumps and investigated by time-resolved X-ray diffraction using synchrotron radiation--are discussed. Mechanistic models for these thermotropic and barotropic phase transitions obtained from these jump relaxation measurements under non- equilibrium conditions are discussed. In particular, linear or non-linear non-equilibrium, phospholipid phases and transitions, diffraction from partly ordered and disordered lipid systems, and lipid polymorphism are discussed. Then X- ray diffraction with synchrotron radiation, and especially time-resolved X-ray diffraction on lipid phase transitions (T-jumps), pressure jump induced phase transitions, and radiation damage are reviewed. Finally, conclusions are drawn and more than 60 references are listed.
Morphology of physical polymer gels as observed by SAXS and SANS
N. Mischenko, K. Reynders, H. Reynaers
The morphology of the triblock copolymer gels ABA type, where A constitutes a thermoplastic material (e.g. PS) and B an elastomer (e.g. PB), are presented. The triblock copolymer gels can be described as follows: PS endblocks form spherical domains with small polydispersity of radius in a homogeneous of dissolved midblock and solvent. The conformation of the midblock can be close to that of statistical coil in good solvents or a bit compressed and stretched. These elastic links between the PS domains define the short-range order and through the densepaching principle finally influence the morphology of the gel. The order is liquid-like with a mean interdomain distance that is 2 - 3 times larger than the mean diameter of the domains. The results of stretching experiments are consistent with a model of a polymer network exhibiting local coordination (short-range) order.
Fractal structure of polymer particles
Andrzej Wlochowicz, Czeslaw Slusarczyk
Small-angle X-ray scattering is an important method for studying the structure of fractals and other disordered systems on a scale of lengths from about 1 to 200 nm. This review begins with a short outline of some properties of fractals. Next the X-ray scattering from fractal systems is discussed. The intensity of small-angle scattering from fractals and other disordered systems often obeys so called power-law scattering. According to this, the scattering intensity is proportional to a negative power of the quantity s equals 4(pi) (lambda) -1sin(theta) , where 2(theta) is the scattering angle and (lambda) is the X-ray wavelength. From the magnitude of the exponent much important information can be obtained. To illustrate the scattering from fractals, several experimental investigations of surface fractals in styrene based ionomers are reviewed.
Structure development during preparation, crystallization, and melting of polymer mixtures
Josef Baldrian
The structure and properties of multicomponent polymeric systems depend on interactions between individual components. The study of these problems are presented for three systems: mixture of POE with benzoic (BA) or glutaric (GA) acids, blends of POE with PMMA and blends of PA6 with ABS. The structure of the blends was characterized by means WAXS, SAXS, SWAX and DSC method.
Plastic deformation of the amorphous component in semicrystalline polymers
Z. Bartczak, Andrzej Galeski, A. S. Argon, et al.
The molecular orientation of the amorphous components of semicrystalline high density polyethylene induced by plane strain compression was studied by wide angle X-Ray scattering measurements utilizing pole figure technique and separation of scattering provided by crystalline and amorphous component. It was found that the oriented amorphous component produced by large strain plastic deformation consist of the domains of extended chain segments closely packed in a 2D pseudohexagonal aggregation, separated by less ordered regions. The deformation leads to the formation of the texture of the amorphous component common for the whole sample. In this texture the direction of chains coincides with the direction of flow and one of (100) pseudo-planes of the pseudohexagonal structure in every domain is perpendicular to loading direction. It was suggested that the most important deformation mechanisms in the ordered amorphous component were the glide of the chain segments along their axes and slip of the pseudo-planes of ordered chains in the direction perpendicular to chain axis, both resembling the crystallographic slip processes. Such specific deformation of the amorphous layers resulted most probably from the strong constraint imposed by the slip deformation in the crystalline component to which amorphous component is intimately connected.
Structure investigations of PP-PA blends
Jaroslaw Janicki, Andrzej Wlochowicz, Czeslaw Slusarczyk
In the paper we have used the SAXS method in order to determine the supermolecular structure parameters, including the transition layer thickness, of polypropylene/polyamide-6 (PP/PA) blends. The transition layer thickness has been obtained by means of two methods elaborated by Koberstein and co-workers and by Ruland, respectively. Both these methods assume that changes of the electron density in the transition region can be described by a Gaussian function with a standard deviation (sigma) . The parameter (sigma) have been determined graphically from the appropriate plots. Then, the thickness of the phase boundary E was estimated as (root)12(sigma) . The investigated PP/PA blends are multiphase systems and the problem of determination of the boundary width is more complicated because the meaning of Porod's law must be considered with caution. This problem is discussed based on wide range of the investigated samples prepared over various pressure and crystallization temperature conditions.
Polymer and X-Ray Scattering Theories and Practice
icon_mobile_dropdown
Radial distribution function in polymers
Wladyslaw Przygocki
Radial distribution function is a very useful tool for determination of the polymer structure. The connection between the scattered X-ray intensity and radial distribution function is presented. Some examples of RDF for polyethylene and for poly(ethylene terephtalate).
Relationship between structure and enzymatic degradation of poly(3-hydroxybutyrate)
Maurizio Canetti, Patrizia Sadocco
The structure of poly(3-hydroxybutyrate) samples with different thermal history was investigated with the aim of explaining the differences in the kinetic of enzymatic degradation. The results confirmed that the increase of the crystallinity is not the only structural parameter enhancing the PHB resistance to the enzymatic degradation, but the crystal dimensions can strongly affect the rate of enzymatic degradation.
Refinement of molecular and crystal structure of poly-(p-phenylene sulphide ether)
Jozef Garbarczyk, Grzegorz Kamyszek
The structure of crystal phase of untreated newly synthesized poly-(p-phenylene sulphide ether) (PPSE) was analyzed by means WAXS method and computer modeling. It was shown that PPSE has crystal structure similar to the PPS.
Natural fibers/polypropylene composite: processing and preliminary structural investigations
Dominik Paukszta, Jozef Garbarczyk
Biodegradation and physico-mechanical properties allow us to predict a wide application of cellulosic/thermoplastic composites and it is an essential motive for investigations on structure-properties relationship. The preliminary investigations on the structure of composites containing isotactic polypropylene with hemp or flax are presented.
Determination of the crystallinity of polymer blends
Stanislaw Rabiej, Ryszard Kwiatkowski, Andrzej Wlochowicz
A new method of the determination of the crystallinity of polymer blends was employed for the blends composed of a semicrystalline polymer and an amorphous copolymer (PE/ABS and PP/ABS). The diffraction curves of the blends were resolved into the contributions arising from each component and then, the contribution from the semicrystalline component was resolved into crystalline and amorphous parts using the least squares method.
Structural investigations of selected conducting polymers using x-ray diffraction and synchrotron radiation scattering
Wojciech Luzny
Two types of conducting polymers: poly(alkylthiophenes) and polyaniline were subjected to the structural investigations using X-ray diffraction and synchrotron radiation scattering. Also, the computer modeling were performed in order to obtain the interpretation of diffraction data, and to get some information on the molecular conformation of the polymers studied.
Errors in x-ray intensity measurements by means of 2D position-sensitive detector
Andrzej Wasiak, Pawel Sajkiewicz
The aim of the present work is determination of characteristic of the 2D position sensitive detector in order to establish conditions, limitations and corrections needed for quantitative measurements of the intensity of scattered X-ray radiation. The analysis of the possibility to introduce corrections of nonuniformities in sensitivity of the detector along its surface, being responsible for distortions in the measured intensity profiles.
Database of organic polymers (polybase)
J. Hasek, D. Janeba
The database of organic polymers `PolyBase-Release 1.1' contains information about crystalline structure for more than 1000 polymers and the full 3D structure is described for 261 of them. Because of low ordering in polymeric materials, the quality of refined coordinates is lower in comparison with low molecular and biological samples.
Software package for small-angle scattering data treatment
Ryszard Diduszko, Lucjan Pajak
A software package for analysis of small-angle scattering data are presented. The program DPSAS-PR enables a preliminary treatment of data obtained from different small angle cameras and the DPSAS-CR program corrects for a finite slit length and possibly for slit width distortions using the Lake, Schmidt and Vonk methods.
Particles and Extrudates, Aggregation and Gelation
icon_mobile_dropdown
Behavior of small-angle scattering intensity tails
S. Ciccariello
The theoretical analysis of the SAXS intensity tails are presented. Based on the obtained results the existence of an asymptotic q-range can be ascertained only a posterior by looking at the physical reliability. A more refined analysis can be numerically performed throughout the explored q-range by using the complete form factors of the particles in order to attempt the determination of the particle polydispersity.
Determination of volume fraction and size distribution by use of a stochastical model from small-angle scattering
Wilfried Gille
Here a method is presented which determines the size distribution density V(D) of small spherical grains with an apparent diameter D, so called primary grains or primary particles, which are arranged at random positions. By use of presented theory it is possible to describe a wide spectrum of random two-phase systems based on SAXS experiments.
Small-angle x-ray scattering investigations of extrudates
Stanislaw Pikus, Jerzy Jamroz
The small-angle X-ray scattering investigations of the extrudes are presented. The investigations of the different samples of starch by means of the SAXS indicate the new possibilities for using this method for extrudates examination. Results obtained by SAXS method of close dependance between intensity SAXS scattering and characteristic parameters of the extrudates were shown.
Particle growth, aggregation, and gelation of silicas
P. H. Bolt, W. H. Dokter, Theo P. M. Beelen, et al.
Silica syntheses have performed by acidification of water glass under various reaction conditions and analyzed beams of SAXS method. SAXS spectra recorded during simultaneous dosing of water glass and sulfuric acid have shown clearly that primary SiO2 particles grow continuously and rapidly during the precipitation. In addition, the primary particles have a rather narrow size distribution, what is surprising result, since the particles are continuously involved in a number of processes: growing, forming interparticle bonds and aging.
Small-angle x-ray scattering studies of base-catalyzed aerogels
Lucjan Pajak
Silica aerogels obtained by the supercritical drying of wet gels prepared by hydrolysis and condensation of alcoholic mixture of Si(OC2H5)4 (tetraethoxysila- ne- TEOS) and water were studied using SAXS, BET and density measurement. Main reason for the interest in the research of the materials prepared from the alcoxides by sol-gel methods is that the liquid state enables manipulation on a molecular level. This permits structural modifications and optimizing the conditions for the further conversion of the gel into glasses and ceramics.
Texture characterization of SiO2-ZrO2 aerogels by SAXS, image analysis of TEM, and N2 adsorption-desorption
S. Blacher, P. Tihon, R. Pirard, et al.
The fractal structure of SiO2-ZrO2 mixed aerogel prepared for catalytic purpose is investigated using morphological statistical methods, small angle X-ray scattering and N2 adsorption-desorption measurements. These three methods provide a description of the aerogel structure over several decades. We have shown that if mixed aerogels are correctly synthesized they may present a hierarchical structure that is not very different from that of pure silica aerogels.