Hot air aging behavior of polypropylene random copolymers

This article deals with the global aging behavior of three polypropylene random copolymer (PPR) materials with varying primary structure and morphology. Hot air aging experiments at elevated temperatures from 95 to 135C were carried out using microsized specimens with a thickness of 100m. Technological and analytical aging indicators were monitored for an exposure time of up to 750days. Independent of comonomer type (ethylene vs. butylene) and morphology ( vs. crystal form) a critical molar mass of 300kgmol1 was obtained. The consumption of antioxidants was slower for the nucleated PPR grade with finer spherulitic structure. The grade outperformed the crystal PPR grades resulting in about 20% higher timetoembrittlement values.(VLID)356326

Laermschutz in Kur- und Erholungsorten Massnahmendokumentation

Although in Germany there have been repeated noise prevention efforts since the 50ies, strain on residential and working population due to noise has been growing steadily. Road traffic noise especially has increased to an extent that is hazardous to health. Municipal authorities of spas (health resorts) and recuperation areas are highly committed to preserving or restoring a calm environment and are therefore specially qualified to take the lead abatement effectuation. This documentation summarises the results of 56 studies and other publications (analyses of the level of noise pollution as well as integrated concepts for noise reduction), which have been written for the benefit of three participating case study municipalities: Bad Pyrmont, Bad Waldsee and Bad Woerishofen. The suggestions of the specialists are subdivided into 9 categories (land use planning, traffic noise, noise from construction sites, neighbourhood noise, low-noise product procurement, public relations work, etc.) and correspond to roughly 70 specific types of action. To render this documentation of particular value to planners, project examples from each of the three participating areas is given. Special emphasis is placed on the legal context, implementation difficulties and the financing of the measures. (orig.)SIGLEAvailable from TIB Hannover: RN 8908(94-073) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Bonn (Germany)DEGerman