Scientific publications

Search abstracts of Borealis' scientific publications. To download pdf versions of Borealis' brochures, case studies, articles, summary data sheets, product news and presentations, please search our literature library.

Authors:	Year:	Key words:

Page: 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

Title	Year
Customised Property Combinations 2007, Peter Niedersüß, Tonja Schedenig, Christelle Grein, Markus Gahleitner, Klaus Bernreitner. Customised Property Combinations Kunststoffe International, 97 (5), 2007, 43-45 Air-quenched blown film was solely a domain of polyethylene until a few years ago. With the polypropylene grades that have since then been introduced into this area of processing technology, the application and property spectrum of films produced by this method has considerably widened. New product developments in the area of random and heterophase copolymers are taking account of this trend and permitting economic solutions in the packaging sector printme	2007
Polypropylene Development - From Catalyst to Customer 2007, Wolfgang Neißl, Markus Gahleitner, Christelle Grein. Polypropylene Development - From Catalyst to Customer SPE International Polyolefins 2007 Conference, Houston/TX, USA, February 25-28,, 2007 Over the last 20 years, the combination of an attractive technical property profile and an advantageous cost position has resulted in a massive volume increase for polyopropylene. The forecasts of market volume are positive for the next years as well, and there are a number of good reasons for that. New developments in the catalyst and process are together with an improved understanding of structure-property relations allow not only designing polymers close to the present customer needs, but also for future and previously not accessible application areas. While Ziegler/Natta type PP catalysts appear to be a mature area, new supporting technologies have opened a range of opportunities. At the same time, single-site PP catalysts are beginning to live up to their earlier promises in terms of yield and product design. New polymerisation plant designs are expanding the product range, and as a consequence of the ever increasing size of polymerisation plants, post-reactor modification is gaining importance for tailoring materials towards special niche market requirements. The wide field of high-impact copolymers has benefited from an improved understanding of relations between molecular structure, morphology and fracture mechanisms, as has the general modulus level of PP from a deeper insight into nucleation and crystallisation mechanisms. A number of new application fields will be presented, demonstrating the unabated innovation strength of PP printme	2007
Highly Transparent Polypropylene Cast Films: Relationships Between Optical Properties, Additives, and Surface Structure 2007, Katharina Resch, Gernot Wallner, Christian Teichert, Markus Gahleitner. Highly Transparent Polypropylene Cast Films: Relationships Between Optical Properties, Additives, and Surface Structure Polymer Engineering and Science, 47, 2007, 1021-32 Polypropylene homopolymer and ethylene/propylenerandom-copolymer cast films formulated with various amounts of slip and antiblocking aids as well as acid scavengers and produced under different processing conditions were characterized with respect to surface structure and optical properties. The topographical analysis was done by atomic force microscopy (AFM). Optical properties were determined using a hazemeter and an UV/Vis/NIR spectrophotometer. AFM height images revealed a significant influence of processing conditions on the development of surface structures. Besides the occurrence of scratches displaying the replica of the metallic chill roll, particularly characteristic eight-shaped superlamellar crystalline features were affected by the cooling conditions. Relationships between surface enrichment of additives and vertical and lateral roughness parameters were established. In general, film types formulated without additives exhibit better optical properties. For film types formulated with polymer-processing aids, the diffuse-scattering power is reduced by low molecular weight, high amounts of acid scavenger aid, and antiblocking agents with low porosity. A separation of haze into its bulk and surface components indicated that total haze is dominated by surface haze. The comparison of haze and the vertical roughness parameters exhibited a tendency of a linear correlation. printme	2007
Thermal history in processing and post-processing steps influencing the mechanical strength of polypropylene 2007, Markus Gahleitner, Maria Parisi, Sybille Frank, Stefano Piccarolo, Doris Machl. Thermal history in processing and post-processing steps influencing the mechanical strength of polypropylene Nordic Polymer Days 2007, Helsinki / Finland, May 29th-31st, 2007 Long-term stability of plastic parts is not just determined by their chemical stability, i.e. their resistance to chain breakdown and decomposition, but also by the evolution of their mechanical properties over time. While chemical ageing of polymers has been studied widely, mostly in connection with stabilization efforts, the effects of physical ageing and (in case of semicrystalline polymers) stabilization of morphologypost-crystallisation have received much less attention. Earlier research in the frame of the EU-FP5-project DECRYPO have already shown strong effects of thermal history in the processing (cooling rate) and the post-processing phase (annealing) on modulus, impact strength and transparency of polypropylene. The effects can be understood by a combination of mechanisms ranging from change in concentration of rigid amorphous phase, secondary crystal formation through lamellar thickening up to interfacial strengthening effects in multiphase impact copolymers. These results will be summarized briefly, followed by a presentation of recent findings for post-crystallisation effects in gamma- and sigma-phase PP. Fracture mechanisms are clearly changed in annealing above the crystalline mobility transition (Tc), shifting the brittle-to-ductile transition to lower temperatures. The practical consequences of such changes on long-term stability under application conditions will finally be outlined. printme	2007
Italian Sewage and Drainage pipe systems: Dynamic prospective with the new generation of PP-HM materials 2007, Carl-Gustaf Ek, Christian Goetzloff. Italian Sewage and Drainage pipe systems: Dynamic prospective with the new generation of PP-HM materials Plastic Pipes & Fittings (SYSTERM S.p.A. Milano), (No 67), 2007, 10-24 (In Italian.)Polypropylene (PP) materials have been successfully used for the manufacturing of piping systems for a long time and have demonstrated their performance in pressure and non-pressure applications. Polypropylene block copolymers (PP-B) are predominantly used for the manufacturing of non-pressure sewage and drainage pipe systems. The latest generation of PP-B ma-terials- so-called PP-HM class (PP with higher modulus) - have been introduced in Italy few years ago and several Italian leading pipe manufacturers have de-signed innovative pipe systems with this new class of materials. The country is definitively now on track to shift from traditional materials (concrete, vitrified clay) to PP-HM based solutions for non-pressure sewage and drainage pipe systems. printme	2007
Mechanical Properties of High-Density Polyethylene and Crosslinked High-Density Polyethylene in Crude Oil and Its Components 2006, J. E. Ritums, A. Mattozzi, U.W. Gedde, M. S. Hedenqvist, G. Bergman, Magnus Palmlof. Mechanical Properties of High-Density Polyethylene and Crosslinked High-Density Polyethylene in Crude Oil and Its Components Journal of Polymer Science: Part B: Polymer Physics,, 44, 2006, 641648 The tensile and stress-relaxation properties of an uncrosslinked and a loosely silane-crosslinked high-density polyethylene exposed to organic 'crude-oil' penetrants were assessed. The measurements were performed on penetrant-saturated samples, surrounded by the organic liquid throughout the experiment. The penetrant solubilities in the two polymers were similar and in accordance with predicted values based on the solubility parameter method. The stiffness and strength of the swollen samples were significantly less than those of the dry samples, indicating a plasticization of the amorphous component. Raman spectroscopy on polyethylene exposed to deuterated n-hexane revealed a penetrant-induced partial melting/dissolution of the crystal surface and an intact crystal core component. The stress-relaxation rates, within the time frame of the experiment (1 s to 18 h), were approximately the same, independent of silane-crosslinks and the presence of penetrants. This indicated that the mechanical a-relaxation, which is the main relaxation process occurring in the measured time interval, was not affected by the penetrants. Consequently, its rate seemed to be independent of the crystal surface dissolution (decrease in the content of crystal-core interface). The shape of the 'log stress-log time' curves of the swollen samples was, however, different from that of the dry samples. This was most likely attributed to a time-dependent saturation of penetrant to a higher level associated with the stretched state of the polymer sample. The silane crosslinks affected only the elongation at break, which was less than that of the uncrosslinked material printme	2006
Design of polyolefin reactor mixtures 2006, Andrew J. Haslam, Øivind Moen, Claire S. Adjiman, Amparo Galindo, George Jacksona. Design of polyolefin reactor mixtures Multiscale Modelling of Polymer Properties 301, M. Laso, E.A. Perpete (Editors), Chapter 5, 2006, 301-332 Polyolefins were among the first plastics produced, with roots back to 1933 when ICI made the first grams of polyethylene. Polyethylene was the material that made RADAR a practical instrument by offering good electrical insulation, enabling instrumentation for warning of attacks. It had a deciding influence on the outcome of World War II. The main uses of polyolefins today are in packaging, giving a substantial environmental benefit by reducing the weight of goods to be transported and thereby reducing the amount of hydrocarbons burnt by lorries. Without polyolefins it would also be difficult to imagine today's supermarket where food and goods are packed in clear plastics, giving the customer the opportunity to inspect goods prior to purchase. printme	2006
Are Aluminoxanes Nanotubular? Structural Evidence from a Quantum Chemical Study 2006, Mikko Linnolahti, John R. Severn, Tapani Pakkanen. Are Aluminoxanes Nanotubular? Structural Evidence from a Quantum Chemical Study Angewandte Chemie International Edition - Wiley InterScience, 7 April, 45 (20), 2006, 3331-3334 No abstract printme	2006
Effect of phase compatibilisation on the surface stability of PP/filler compounds 2006, Tung Pham. Effect of phase compatibilisation on the surface stability of PP/filler compounds PPS 22 International Conference, Yamagata , Japan, 02.-06.07, 2006 Surface stability of multiphase polymer systems (e.g. PP/rubber) depends very strongly on the phase separation behaviour in the surface region. The role of interface management between PP and rubber phases in this region, e.g. control of miscibility between the components, is a major factor affecting the ability of the moulded part to resist surface damage caused by external forces. Stresses applied to PP/rubber part often results in cohesive debonding due the weak interface of the systems. By applying Borealis proprietary modification technology utilising chemical reaction during melt processing, PP compounds with excellent surface stability and paint adhesion capability have been developed. Investigation of the morphology of the surface region gives an inside view of the surface stability/damage mechanism. printme	2006
Multiphase PP Blends for Automotive Interior: Composition Effects on Surface Structure and Scratch Resistance 2006, Doris Machl, Christelle Grein, Klaus Bernreitner. Multiphase PP Blends for Automotive Interior: Composition Effects on Surface Structure and Scratch Resistance SPE ANTEC 2006, Charlotte, NC, USA, 07.-11.05., 2006 This paper outlines surface properties like scratch and gloss performance in PP/EPR blends consisting of a PP matrix and a dispersed EPR phase with crystalline PE core particles. A brief overview of the influence of intrinsic polymer parameters and processing conditions is given. The shape and size of the dispersed EPR in polypropylene resin have a strong impact on both gloss and scratch performance. One of the major factors will be the molecular weight of the EPR particles. The bigger they are, the lower the gloss and the higher the scratch resistance. In addition to polymer design, processing conditions play a major role. It was found that injection speed is one of the main controlling factors during injection molding. printme	2006