Estabilizante orgánico para PVC. Alternativa eficiente para tubos de PVC

Se describen los estabilizantes con base orgánica como alternativa en la fabricación de tubos de PVC en respuesta a consideraciones ambientales y políticas, las cuales exigieron el reemplazo del plomo por alternativas menos contaminantes.

Halogen-free flame-retardant compounds. Thermal decomposition and flammability behavior for alternative polyethylene grades

The effect of six halogen-free flame retardant (FR) formulations was investigated on the thermal stability of two low-density polyethylenes (LDPE) and one linear low-density polyethylene (LLDPE), by means of thermogravimetric analysis (TGA) under nitrogen and air atmosphere. The relative data were combined with flammability properties and the overall performance of the FRs was correlated with the type of branching in the polyethylene grades and to their processing behavior. The thermal degradation kinetics was further determined based on the Kissinger and Coats-Redfern methods. In terms of flammability, the addition of a triazine derivative and ammonium polyphosphate at a loading of 35 wt. %. was found to be the most efficient, leading to UL 94 V0 ranking in the case of the LDPE grade produced in an autoclave reactor. - 2019 by the authors.Funding: 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). The statements made herein are solely the responsibility of the author(s)

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

Flame Retardants for Polyethylene

Achieving flame retardant polyethylene, which is required in many applications such as wire and cable, is challenging due to its flammability. The flame-retardants in use today consider dif ferent flame retardant mechanisms such as endothermic decomposition, gas phase reaction, and intumescence. Therefore, available solutions range from the addition of mineral fillers through brominated and phosphorus compounds to radical generators. A suitable flame retardant has to be selected according to the application, the standards to be fulfilled, and the influence of the selected flame retardant on the overall properties of polyethylene

(Photo)oxidative stabilization of flame-retarded polymers

Flame-retarded polymer formulations are mainly used in long-term applications whereas antioxidants, light stabilizers, and other additives provide the requested lifetime of plastic materials. However, many flame retardants influence the oxidative and photooxidative stability of polymers often in a negative way resulting in early failure and loss in value. On the other side, insufficient (photo)oxidative stability of the flame retardant itself may reduce the flame retardance performance over time. Therefore, depending on the type of flame retardant used, the polymer substrate and the intended application adjusted stabilizer systems have to be selected or developed.In this chapter, challenges of the stabilization of flame-retarded polymers are analyzed with regard to the components and mutual interactions with focus on "green" flame retardants. Processing and long-term thermal stabilization of flame-retarded polymers are discussed and strategies of improving the light sta bility of flame-retarded polymers are provided. Additionally, the specific requirements of the stabilization of nanocomposites as potential flame-retardant components are covered

Polymer Additives

Additives are essential components in polymer formulations to maintain and to extend polymer properties. Many additive classes are seen today as commodities and standard products, available from different manufacturers and applied in many use areas. This chapter presents the most important classes of additives as well as general information on chemical structures and mechanisms, on testing methods, and on use examples in selected polymer classes. The additive classes are antioxidants, poly vinylidene chloride (PVC) heat stabilizers, light stabilizers, flame retardants, plasticizers, and scavenging agents. The chapter also talks about other additives to enhance processing, modify plastic surface properties, modify polymer chain structures, influence morphology and crystallinity of polymers, and enhance thermal conductivity. The other topics covered in this chapter are active protection additives, antimicrobials, odor masking, animal repellents, markers, and blowing agents