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Showing 1 to 20 of 52 for “"polyolefins"”.
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Thermodynamic properties of polyolefins
The purpose of this investigation was to determine thermodynamic properties for linear polyethylene, polypropylene and an ethylenepropylene copolymer, from previously determined p-v-t and calorimetric data. The entropy and enthalpy were calculated from calorimetric and p-v-t data using a datum of …
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Versatile Strategies for Multifunctional Polyolefins
Polyolefins have quickly become one of the world’s most utilized products since their discovery in the 1950s. With 350 million tons produced each year, it is clear that the use of polyolefins is not subsiding in the near future. Instead, it is imperative to develop novel materials that are more …
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Upcycling of Polyolefins Through Functionalization
… of a range of materials used in modern society. Polyolefins (PO), mainly low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polypropylene (PP), constitute ~57% of global plastic production, taking an essential role in our every day. Yet, the versatility and convenience of …
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Understanding Heterogeneous Nucleation Mechanisms in Polyolefins
The family of polyolefins are among the most widely used semi-crystalline polymers in the modern world, with many of their desirable properties due to their microstructure formed during crystallization. While processing conditions have a large impact on crystallization, an additional tool is the …
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The mechanisms of melt stabilisation of polyolefins
… melt stabilisers on the oxidative degradation of polyolefins (polypropylene, low density polyethylene) have been studied under a variety of processing conditions . The changes in the both chemical and physical properties of unstabilised polymers occurring during processing were found to be …
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Reactive processing of polyolefins using antioxidant systems
Various monoacrylic compounds containing a hindered phenol function (e.g.3,5-di-tert.-butyl-4-hydroxy benzyl alcohol, DBBA and vinyl-3-[3',5'-di-tert.-butyl-4-hydroxy phenyl] propionate, VDBP), and a benzophenone function (2-hydroxy-4-[beta hydroxy ethoxy] benzophenone, HAEB) were synthesised and …
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Fading of Substituted phenylazo - B - naphthols on polyolefins
… so as to interpret conclusions in terms of polyolefins."
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A Study of Phosphorus-Containing Antioxidants in Polyolefins
Metal dithiophosphonates (Ni, Zn, Fe, Co, Cu) and the corresponding sulphide, TPS, were examined as potential antioxidants in polypropylene. All the dithiophosphonates were very good melt stabilisers when compared to commercial controls. Their effectiveness as thermal antioxidants varied …
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The antioxidant role of vitamin E in polyolefins
… antioxidants are important stabilisers for polyolefins. However, hindered phenols undergo chemical transformations while performing their antioxidant function during processing and fabrication. In addition, antioxidants are subject to loss from polymers during processing, or subsequently …
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Additive manufacturing of polyolefins via powder bed fusion
… which can lead to print failure is possible. Polyolefins represent a class of thermoplastic chiefly comprised of polyethylene and polypropylene. These materials are highly used in engineering applications however, their rapid crystallization kinetics generally make them much less suitable for …
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From waste to resources: tailored recycling strategies for polyolefins
L'abstract è presente nell'allegato / the abstract is in the attachment
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Bonding of additives to functional polyolefins by reactive blending
… studied the bonding of colorants to functional polyolefins and the second part investigated the bonding of UV stabilisers to functional polyolefins. The research was completed with the long term objective that the approach should offer alternative additives to conventional non-bonded systems for …
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The mechanochemical modification of polyolefins using reactive modifier systems
The principal objective of this work was to improve the mechanical properties of glass fibre reinforced polypropylene (PP) composites by the mechanochemical modification of the PP. The modification of the PP was carried out by reactive processing of the PP with a modifier in a Buss Ko-Kneader. Two …
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Kinetic modeling frameworks for the chemical recycling of polyolefins
… frameworks for the chemical recycling of polyolefins. First, we examine mass-transfer limits using a diffusion–reaction model that describes how processive catalysts perform inside stagnant and stirred polymer melts. The core of the dissertation then advances the mechanistic modeling for …
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Time controlled photo-oxidation of polyolefins by polymer bound additives
A variety of iron compounds containing vinyl or thiol functional groups (used as photoactivators) have been synthesised and some of these were successfully bound to both polyethylene and polypropylene backbones during processing in the presence of peroxide and interlinking agent. Concentrates …
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Microinjection moulding and material testing of polyolefins on a small scale
De onderzoeksgroep SMaRT (KU Leuven) concentreert zich op polymeren en colloïdale dispersies om nieuwe materialen te ontwikkelen en hun verwerkingsgedrag te bestuderen. De ontwikkeling en studie van nieuwe materialen is een uitzonderlijk lang en duur proces. Voor de studie van het verwerkingsgedrag …
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