Mode of Action of Zn-DOPOx and Melamine Polyphosphate as Flame Retardants in Glass Fiber-Reinforced Polyamide 66

In this study, the flame retardant effect of the Zn salt of 10-hydroxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (Zn-DOPOx), melamine polyphosphate (MPP) and their mixture was investigated towards the mode of action in glass fiber-reinforced polyamide 66 (PA 66 GF). The flammability was evaluated using UL 94 V and cone calorimetry. Influence on char formation was analyzed by SEM. Thermal decomposition of Zn-DOPOx and MPP was studied by TGA and ATR-FTIR. The release of gaseous PA 66 decomposition products was investigated using TGA-DTA-FTIR. Combining Zn-DOPOx and MPP leads to an improvement in flame retardancy, most pronounced for equal parts of weight. Mode of action changes significantly for Zn-DOPOx:MPP (1:1) compared to the sole components and a strong interaction between Zn-DOPOx and MPP is revealed, resulting in a more open char structure. Fuel dilution as well as less exothermic decomposition are essential for the mode of action of the combination. Through low HRR values and high CO/CO₂ ratio during cone calorimetry measurements, a significant increase in gas phase activity was proven. Therefore, it is concluded that Zn-DOPOx:MPP (1:1) leads to a significant increase in flame retardancy through a combination of mode of actions in the gas and condensed phase resulting from the change in thermal stability

Disulfides – Effective radical generators for flame retardancy of polypropylene

The potential of thirteen aliphatic, aromatic, thiuram and heterocyclic substituted organic disulfide derivatives of the general formula R-S-S-R’ as a new group of halogen-free flame retardants (FR) for polypropylene films have been investigated. According to DIN 4102-1 standard ignitibility test, for the first time it has been demonstrated that many of the disulfides alone can effectively provide flame retardancy and self-extinguishing properties to polypropylene (PP) films at already very low concentrations of 0.5 wt%. In an effort to elucidate the mechanism of the thermal decomposition of disulfide derivatives the fragmentation patterns of the evolved gases from a thermogravimetric analyzer (TGA) have been analyzed by simultaneous mass spectrometry (MS) and Fourier transform infrared spectrometry (FTIR). The main decomposition products initiated by homolytic scission of the S-S bond and/or scission of the C-S bond were identified as thiols, aliphatic and aromatic hydrocarbons, isothiocyanates (depending on the disulfide structures) with further evolution of elemental sulfur and sulfur dioxide at temperatures of above 300 oC and 450 oC, respectively. Based on this preliminary study, we have shown that disulfides represented by e.g. diphenyl disulfide (1), 5,5'-dithiobis(2-nitrobenzoic acid) (2), bis(1-phenyl-1H-tetrazol-5yl)-disulfide (4), 2-bisbenzothiazole-2,2′-disulfide (6) and N,N-dithiobis-(phtalimide) (10) constitute a new halogen-free family of additives for flame retarding of polypropylene

An Integrated Characterization Strategy on Board for Recycling of poly(vinyl butyral) (PVB) from Laminated Glass Wastes

: Polyvinyl butyral (PVB) is widely used as an interlayer material in laminated glass applications, mainly in the automotive industry, but also for construction and photovoltaic applications. Post-consumed laminated glass is a waste that is mainly landfilled; nevertheless, it can be revalorized upon efficient separation and removal of adhered glass. PVB interlayers in laminated glass are always plasticized with a significant fraction in the 20-40% w/w range of plasticizer, and they are protected from the environment by two sheets of glass. In this work, the aim is to develop a thorough characterization strategy for PVB films. Neat reference PVB grades intended for interlayer use are compared with properly processed (delaminated) post-consumed PVB grades from the automotive and construction sectors. Methods are developed to open opportunities for recycling and reuse of the latter. The plasticizer content and chemical nature are determined by applying well-known analytical techniques, namely, FT-IR, TGA, NMR. The issue of potential aging during the life cycle of the original laminated material is also addressed through NMR. Based on the findings, a sensor capable of directly sorting PVB post-consumer materials will be developed and calibrated at a later stage

Enhancing the UV/heat stability of LLDPE irrigation pipes via different stabilizer formulations

Herein different stabilizer formulations of linear low-density polyethylene (LLDPE) against UV- and heat-initiated degradation are described. The project aims at outdoor applications, such as irrigation piping and profiles, in the Middle East desert regions, where long-term weathering stability due to high temperatures and solar radiation is important. Two UV/heat formulations, without and with carbon black (CB) as pigment, were incorporated into LLDPE by melt compounding. Neat LLDPE and the stabilized compounds were exposed to accelerated UV and heat aging. Morphological analysis through scanning electron microscopy of the UV-exposed neat LLDPE showed more severe surface cracking compared to the CB-containing LLDPE, while all stabilized compounds did not show any surface degradation. Crack formation was less visible for the thermally aged samples. A significant decrease in molecular weight (MW) was observed for the neat UV-exposed LLDPE, while both unpigmented stabilized compounds showed little change in MW. Mechanical properties, thermal analysis, and carbonyl index results supported the morphological results, which confirmed that CB alone was slightly more effective in protecting the LLDPE against UV initiated degradation, but performed worse against thermal initiated degradation. UV1 and UV2 compounds were efficient against both UV- and heat-initiated degradation, with UV1 performing better for unpigmented compounds, and UV2 for the pigmented ones.This publication was made possible by the NPRP award (NPRP 9-161-1-030) from the Qatar National Research Fund (a member of The Qatar Foundation). We are also grateful to BASF and Sabo for supplying the additives at no cost. We further express our gratitude to Dr. Robert Brüll from Fraunhofer LBF, Darmstadt, Germany for doing the GPC analyses on our samples. The statements made herein are solely the responsibility of the author(s).Scopu

Plastic Additives

Additives are essential components of plastic formulations providing maintenance and/or modification of polymer properties, performance, and long‐term use. Additive means any ingredient which is incorporated in a polymer (or a polymer blend), which is usually the main component, to provide a plastic formulation with adjusted properties. The extension of polymer properties by additives has been playing a substantial role in the growth of plastics, and many polymer applications are only accessible in the presence of a number of ingredients, often only in small quantities, in addition to the polymer itself. As real new polymer structures of standard plastics or engineering plastics are not introduced any more, additives drive innovation in the plastics area to design properties and functions of polymers

Polymerzusammensetzung mit verzögertem Kristallisationsverhalten, das Kristallisationsverhalten beeinflussende Additivzusammensetzung, Verfahren zur Herabsetzung des Kristallisationspunktes sowie Verwendung einer Additivzusammensetzung

Die vorliegende Erfindung betrifft eine Polymerzusammensetzung, die eine Matrix aus mindestens einem kristallisationsfähigen thermoplastischen Polymeren, sowie hierin eingearbeitet mindestens einen Azinfarbstoff und/oder mindestens ein-, zwei-, drei- und/oder vierwertiges Metallsalz sowie mindestens eine ionische Flüssigkeit beinhaltet oder hieraus besteht. Diese Polymerzusammensetzung zeichnet sich dadurch aus, dass ihr Kristallisationspunkt gegenüber nicht-additivierten Polymerzusammensetzungen merklich verringert ist. Zusätzlich betrifft die vorliegende Erfindung eine entsprechende Additivzusammensetzung zur Kristallisation und/oder zur Erniedrigung des Kristallisationspunktes von kristallisationsfähigen thermoplastischen Polymeren oder Polymerzusammensetzungen

Polymerzusammensetzung mit verbesserter Langzeitstabilität, hieraus hergestellte Formteile sowie Verwendungszwecke

The present invention relates to a polymer composition having improved long-term stability, which contains or consists of at least one thermoplastic polymer, carbon nanotubes, at least one antioxidant and at least one additive. The present invention also relates to moulded parts that can be produced from the polymer compositions according to the invention. The invention also specifies possible uses of the polymer composition and the moulded parts

Verfahren zur Erniedrigung der Kristallisationstemperatur von teilkristallinen Polyamiden, hierdurch hergestellte Polyamidformmasse sowie Verwendung von mehrfunktionellen umesterungsfähigen organischen Phosphoniten, organischen Phosphiten, organischen Phosphaten bzw. Mischungen hiervon zur Erniedrigung der Kristallisationstemperatur, zur Vernetzung und/oder Verzweigung von teilkristallinen Polyamiden

The invention relates to a method for lowering the crystallization temperature of semicrystalline polyamides, wherein at least one semicrystalline polyamide or mixtures of at least two semicrystalline polyamides are mixed with at least one polyfunctional transesterification-capable organic phosphonite, organic phosphite, organic phosphate or mixtures of at least two of the previously mentioned compounds, the formed mixture is converted into a melt, wherein the at least one polyfunctional transesterification-capable organic phosphonite, organic phosphite, organic phosphate or the mixtures of at least two of the previously mentioned compounds are transesterified, with simultaneous transamidation of the at least one semicrystalline polyamide, and finally the mixture is cooled