Polymer Characterization Techniques Research Articles

Characterization of post-etched photoresist and residues by various analytical techniques

In advanced interconnect applications, the possibility to remove completely photoresist layers is one of the key points. To have the maximum removal efficiency, the selection of the needed chemistries is of first importance. To this end, the characterization of post-etched photoresists can be used to support that selection. The complete work includes the use of various spectroscopic and polymer characterization techniques. In the present paper, results obtained by time of flight-secondary ion mass spectrometry (ToF-SIMS), angle-resolved X-ray photoelectron spectroscopy (AR-XPS) and Auger electron spectroscopy (AES) are presented for the characterization of post-etched photoresist used in photoresist mask patterning schemes.

An Effective On-line Polymer Characterization Technique by Using SALS Image Processing Software and Wavelet Analysis

This paper describes an effective on-line polymer characterization technique by using small-angle light-scattering (SALS) image processing software and wavelet analysis. The phenomenon of small-angle light scattering has been applied to give information about transparent structures on morphology. Real-time visualization of various scattered light image and light intensity matrices is performed by the optical image real-time processing software for SALS. The software can measure the signal intensity of light scattering images, draw the frequency-intensity curves and the amplitude-intensity curves to indicate the variation of the intensity of scattered light in different processing conditions, and estimate the parameters. The current study utilizes a one-dimensional wavelet to delete noise from the original SALS signal and estimate the variation trend of maximum intensity area of the scattered light. So, the system brought the qualitative analysis of the structural information of transparent film success.

Mathematical modeling of crystallization analysis fractionation of ethylene/1‐hexene copolymers

AbstractCrystallization analysis fractionation (Crystaf) is a polymer characterization technique for estimating the chemical composition distributions of semicrystalline copolymers. Although Crystaf has been widely used during the recent years, it is still a relatively new polymer characterization technique. More quantitative understanding of its fractionation mechanism is essential for further developments. In this work, three ethylene/1‐hexene copolymers with different 1‐hexene fractions, but similar number‐average molecular weights, were analyzed by Crystaf at several cooling rates. A mathematical model was proposed to describe the effect of comonomer fraction and cooling rate on Crystaf fractionation from a fundamental point of view. The model describes the experimental Crystaf profiles of ethylene/1‐hexene copolymers with different 1‐hexene fractions measured at distinct cooling rates very well. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1010–1017, 2007

質量分析法を用いたポリマー材料の構造解析

The development of new polymer characterization techniques is constantly required to understand the various properties of polymers and create new functional polymers. In this study, two mass spectrometry (MS) approaches have been investigated: temperature programmed pyrolysis-mass spectrometry (TPPy-MS) and soft laser desorption/ionization-mass spectrometry (SLD-MS). The study can be summarized as follows: 1) A TPPy-MS system was developed to overcome the limitations of conventional evolved gas analysis (EGA) systems such as thermogravimetry/MS (TG/MS). The TPPy-MS system was used to investigate the mechanisms of thermal degradation of an engineering polymer with a brominated flame-retardant, and the intermolecular interaction mechanisms of miscible polymer blends and polymer/clay hybrids. 2) Matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) was employed to characterize the chemical structure of each polymer chain. A new data processing method for size exclusion chromatography (SEC)/MALDI-MS was proposed to determine the accurate molecular weight distribution of polymers based on individual oligomer compositions. MALDI-MS was also used to investigate the biodegradation behavior of polymers. Based on the structural changes in each polymer chain, enzymatic degradation mechanisms of a biodegradable polyester and bacterial degradation of surfactants have been proposed. 3) To avoid the use of matrix reagents that frequently interfere with the mass spectra of oligomer and polymer additives, novel ionization platforms for matrix-free SLD-MS were investigated. The etching conditions of porous silicon spots for desorption/ionization on porous silicon-mass spectrometry (DIOS-MS) were optimized to determine the accurate molecular weight distribution of a certified reference polystyrene. Finally, two ionization platforms were developed using a pyroelectric ceramic plate and germanium nanodot deposited on a silicon wafer. The latter method was preferred for characterization of brominated flame-retardants.

High-throughput approaches for the discovery and optimization of new olefin polymerization catalysts.

The discovery of new olefin polymerization catalysts is currently a time-intensive trial-and-error process with no guarantee of success. A fully integrated high-throughput screening workflow for the discovery of new catalysts for polyolefin production has been implemented at Symyx Technologies. The workflow includes the design of the metal-ligand libraries using custom-made computer software, automated delivery of metal precursors and ligands into the reactors using a liquid-handling robot, and a rapid primary screen that serves to assess the potential of each metalligand-activator combination as an olefin polymerization catalyst. "Hits" from the primary screen are subjected to secondary screens using a 48-cell parallel polymerization reactor. Individual polymerization reactions are monitored in real time under conditions that provide meaningful information about the performance capabilities of each catalyst. Rapid polymer characterization techniques support the primary and secondary screens. We have discovered many new and interesting catalyst classes using this technology.

Polymer characterization by combining liquid chromatography with MALDI and ESI mass spectrometry.

High-performance polymers are complex mixtures of materials of different size and chemical composition and with different end groups and architecture. To determine the molecular heterogeneity of such systems, hyphenation of several techniques is required. The value of coupling mass spectrometry (MS) with separation techniques has already been recognized - such methods have proved to be among the most powerful for molecular characterization of complex polymer systems. The review focuses on matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI) MS coupled with liquid chromatography (LC). Such hyphenation has been used for most polymer analysis by mass spectrometry coupled with separation techniques. The advantages and/or limitations of these techniques for polymer characterization are discussed. Future prospects are briefly outlined.

Use of near Edge X-Ray Absorption Fine Structure Spectromicroscopy to Characterize Multicomponent Polymeric Systems

The merits of a polymer characterization technique, near edge X-ray absorption fine structure (NEXAFS) spectromicroscopy, are demonstrated through the characterization of a multilayer polymer film with partially unknown chemical composition. The combination of chemical speciation through NEXAFS spectroscopy with the high spatial resolution available in X-ray microscopy allows the characterization of polymeric materials not possible with conventional techniques. Analysis of a multilayer with layers as thin as 4 μm has yielded results that differ from those previously obtained by infrared microscopy. Layers below the spatial resolution limit of infrared microscopy were characterized.

Using Polymer Characterization Techniques to Predict LDPE Resin Suitability for Extruded Foam Applications

All LDPE resins are not created equal. It is well known that autoclave LDPEs are considered to be the products of choice for extrusion coating applications. On the other hand, LDPE resins produced using tubular reactors have a different structure that makes them more suitable for extruded foam applications. More specifically, within the choices of tubular LDPE resins for extruded foam applications, some are easier to process and produce better quality foam products than others. What makes one resin better than another? This paper discusses the general chemical and rheological differences between autoclave and tubular LDPE resins then focuses in more detail on those differences for a variety of tubular LDPE products used in the extruded foam market.

An Investigation into PEO/Crosslinked-Silicone Semi-Interpenetrating Polymer Network Using1H Solid-State NMR Spectroscopy under Fast MAS

Microstructure and phase behavior of a semi-interpenetrating polymer network consisting of 10% poly(ethylene oxide) and 90% crosslinked-silicone have been studied using various 1H solid-state NMR methods under fast magic angle spinning in combination with well-known polymer characterization techniques. Both, 1H double-quantum MAS NMR spectroscopy as well as NOESY MAS measurements indicate a mixing of the two components on a molecular level.

An Investigation into PEO/Crosslinked-Silicone Semi-Interpenetrating Polymer Network Using 1H Solid-State NMR Spectroscopy under Fast MAS

Microstructure and phase behavior of a semi-interpenetrating polymer network consisting of 10% poly(ethylene oxide) and 90% crosslinked-silicone have been studied using various 1H solid-state NMR methods under fast magic angle spinning in combination with well-known polymer characterization techniques. Both, 1H double-quantum MAS NMR spectroscopy as well as NOESY MAS measurements indicate a mixing of the two components on a molecular level.

Field Emission Scanning Electron Microscopy Studies of Industrial Polymers - A Survey

Abstract We are using the term "Industrial Polymers" to refer to polymers [plastics] that are produced by the ton or (in the case of films) by the mile. For example, in descending order of world-wide use (tonnage), the top eight of these polymers are polyethylene (PE), polyvinyl chloride (PVC), polypropylene (PP), styrene polymers (including polystyrene - PS, and acrylonitrile-butadienestyrene/ styrene-acrylonitrile - ABS/SAN), polyesters (PETP), polyurethane (PU), phenolics and aminoplastics. Industrial polymers, which have been produced by the millions of tons for the last five decades and are of obvious social and economic importance, have been exhaustively characterized. Structural features which affect physical properties and indicate process variables have been studied by many techniques other than microscopy (x-ray diffraction, thermal analysis, rheology, chromatographies, etc.). Microscopy techniques for polymer characterization have been well documented. Our motivation to apply field emission (high resolution) scanning electron microscopy to the study of polymers is: (1) The application of low voltage, high resolution SEM to biological materials is well characterized.

97/00942 Polyethylene degradation in a coal liquefaction environment

The coprocessing of coal with waste materials such as plastic has shown promise as an economical means to recover the inherent value of the wastes while producing useful products. Polyethylene (PE) is one of the dominant plastic materials; recent statistics indicate that low- and high-density PE together make up about half of all municipal plastic waste. The degradation of PE in a pyrolysis environment has been well studied, and pyrolysis-based methods for the conversion of PE to fuels have been published. However, recent studies have shown that PE is among the most difficult plastics to convert in the traditional liquefaction environment, particularly in the presence of coal and/or donor solvents. The coal liquefaction environment is quite different than that encountered during thermal or catalytic pyrolysis. Understanding the degradation behavior of PE in the liquefaction environment is important to development of a successful scheme for coprocessing coal with plastics. In this paper, a novel analytical method has been developed to recover incompletely reacted PE from coprocessing product streams. Once separated from the coal-derived material, gel permeation chromatography, a conventional polymer characterization technique, was applied to the recovered material to ascertain the nature of the changes that occurred to the PE uponmore » processing in a bench-scale continuous liquefaction unit. In a separate phase of the project, 1-L semi-batch reactions were performed to investigate the reactivity of PE and coal-PE mixtures as a function of temperature.« less

Intelligent manufacturing of polymers

Integrated multivariable process control can have a significant strategic impact on polymer plant operability and economics. Polymer manufacturers face increasing pressures for production cost reductions and more stringent “polymer quality” requirements. The main goals in operating a polymer reactor (e.g. high yield, better product quality and safe operation) are very difficult, if not impossible, to achieve without efficient and reliable polymer characterization techniques. Although the weakest link in polymer reactor control is undoubtedly the on-line instrumentation, lack of understanding of the process dynamics, the highly sensitive and nonlinear behavior of polymer reactors and the lack of well structured control strategies all contribute to the impairment of competitiveness. Intelligent manufacturing relates to the harmonious integration of process models, advance sensors, statistical approaches and advanced process control methods.

Low-voltage, high-resolution scanning electron microscopy: a new characterization technique for polymer morphology

Low-voltage, high-resolution scanning electron microscopy (LVHRSEM) is a promising new technique for polymer morphological characterization, and provides complementary data to transmission electron microscopy, X-ray scattering and the scanning probe microscopies. Practically, lateral resolution on the order of 50 Å at 1.0 keV accelerating voltage can be obtained in polymer samples. The utility of LVHRSEM is demonstrated for diverse polymer systems, both amorphous and crystalline, with structurally interesting features on a 50–1000 Å length scale. The advantages and disadvantages of LVHRSEM as a polymer characterization technique are investigated, as well as the effects of beam—sample interactions, radiation damage and contamination specific to polymers examined at low voltage.

Persistence of regions with high segment density in polyethylene melts

AbstractProton nuclear magnetic resonance (NMR) spin‐spin relaxation measurements were made on three commercial‐grade polyethylenes in the melt state, free of solvent. All samples exhibit a three‐component relaxation behavior, with components being assigned to amorphous low‐molecular weight material (non‐network fraction), amorphous entangled network fraction, and an ordered or high‐segmental‐density fraction, in order of decreasing relaxation times. Sample thermal history is shown to have a considerable effect on the overall relaxation behavior, and therefore on the relative amounts of each of the three components in the melt. An adequate thermal treatment of samples produces an equilibrium melt with invariant composition of the three fractions. The effects of thermal history on the relative amount of high‐segment‐density regions in the melt parallels its effect on the fraction of crystalline material in the solid polymer. These results are evidence for the persistence of ordered regions in polyethylene at temperatures well above the crystalline melting point of the polymer. We further comment on the nature of the two slower relaxing components and present examples of how the components manifest themselves in other polymer characterization techniques. © 1992 John Wiley & Sons, Inc.

A thermal evolution — differential trapping — mass spectrometric technique for polymer characterization

The ability of thermal evolution techniques for polymer characterization is greatly enhanced when spectroscopic methods are combined, thus allowing identification of the off-gases. This work describes a thermal evolution—differential trapping—mass spectrometric technique for analysis of polymer systems. The technique involves heating the sample under controlled temperature and pressure conditions, condensing the evolved gases in traps maintained at various temperatures, continuously monitoring the pressure changes at strategic locations, and analyzing the selectivity trapped volatiles by mass spectrometry. Both qualitative and quantitative aspects of the technique will be discussed.