Thermal stability and flame retardancy of polyurethanes

The rising concern towards environmental issues and, on the other hand, the need for more versatile polymer-based materials has led to increasing interest about polymer composites filled with natural-organic fillers, i.e. fillers coming from renewable sources and biodegradable. The composites, usually referred to as “green”, can find several industrial applications. On the other hand, some problems exist, such as worse processability and reduction of the ductility. The use of adhesion promoters, additives or chemical modification of the filler can help in overcoming many of these limitations. These composites can be further environment-friendly when the polymer matrix is biodegradable and comes from renewable sources as well. This short review briefly illustrates the main paths and results of research (both academic and industrial) on this topical subject, providing a quick overview (with no pretence of exhaustiveness over such a vast topic), as well as appropriate references for further in-depth studies.

Green composites: A brief review

Coumarins in polymers: From light harvesting to photo-cross-linkable tissue scaffolds

This century has witnessed remarkable achievements in green technology in material science through the development of natural fiber reinforced composites. The development of high-performance engineering products made from natural resources is increasing worldwide day by day. There is increasing interest in materials demonstrating efficient use of renewable resources. Nowadays, more than ever, companies are faced with opportunities and choices in material innovations. Due to the challenges of petroleum-based products and the need to find renewable solutions, more and more companies are looking at natural fiber composite materials. The primary driving forces for new bio-composite materials are the cost of natural fibers (currently priced at one-third of the cost of glass fiber or less), weight reduction (these fibers are half the weight of glass fiber), recycling (natural fiber composites are easier to recycle) and the desire for green products. This Review provides an overview of natural fiber reinfocred composites focusing on natural fiber types and sources, processing methods, modification of fibers, matrices (petrochemical and renewable), and their mechanical performance. It also focuses on future research, recent developments and applications and concludes with key issues that need to be resolved. This article critically summarizes the essential findings of the mostly readily utilized reinforced natural fibers in polymeric composite materials and their performance from 2000 to 2013.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/mame.201300008

Progress Report on Natural Fiber Reinforced Composites

Composites science and technology

Flame retardancy in thermoplastic polyurethane elastomers (TPU) with mica and aluminum trihydrate (ATH)

A laboratory-sized two-roll mill was used to incorporate rice husk ash into natural rubber (NR). A conventional vulcanization system was used for curing and cure studies were carried out on a Monsanto rheometer. Physical testing of the NR vulcanizates involved determining tensile and tear resistances and hardness. Swelling behavior of NR compounds and scanning electron microscopy were used to investigate the interaction between rice husk ash and natural rubber. Also, dynamical mechanical thermal analysis was used to assess filler–rubber interactions in terms of storage modulus (E′) and loss tangent (tan δ). For comparison purposes, two commercial fillers, precipitated silica (Zeosil-175) and carbon black (N774), were also used. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2331–2346, 2002

Mechanical and dynamic mechanical properties of rice husk ash–filled natural rubber compounds

Life cycle assessment (LCA) is a common technique to evaluate the environmental impact of poly(ethylene terephthalate) (PET) packaging. A review is needed to gain a clear view of the accumulated knowledge, scientific trends and what remains to be done. The main purpose of this paper is to present an overview of LCA of PET, mainly for packaging. LCA studies of PET consist largely of two segments: final destination of post-consumer PET, comparing recycling with other options (incineration, landfilling); and alternative materials, comparing PET with other polymers or materials such as glass and aluminum cans. In the first case, the scenarios most often compared have been landfill disposal and mechanical recycling. There has also been considerable research on the use of post-consumer PET for energy conversion and chemical recycling. In the second case, the main polymer compared with PET is poly(lactic acid), whose mechanical properties make it unsuitable for carbonated beverage bottles. Numerous articles have focused only on energy consumption or global warming potential. Few studies have discussed mechanical recycling technologies in LCA and there is a lack of data on the processes used in developing countries. This review highlights the need to conduct LCA studies of PET, since many aspects are still not fully understood.

Life Cycle Assessment of Polyethylene Terephthalate Packaging: An Overview

Mechanical properties of thermoplastic polyurethane elastomers with mica and aluminum trihydrate

Rice husk ash was incorporated into natural rubber (NR) using a laboratory size two-roll mill. Curing using a conventional vulcanization system (CV) was chosen, and cure studies were carried out on a Monsanto rheometer. Physical testing of the NR vulcanizates involved the determination of tensile, tear, and abrasion resistances, and hardness. Fourier transform infrared spectroscopy (FTIR) analysis was done to verify the presence of the characteristic functional groups of precipitated silica in MHA (milled husk ash) and THA (treated husk ash). The effect of the coupling agent, bis(3-triethoxysilylpropyl)-tetrasulfane (Si-69), on the curing and physical properties of the vulcanizates was investigated. A chemical treatment on a rice husk ash was done, and the effects of this procedure are also reported. For comparison, two commercial fillers, precipitated silica (Zeosil-175) and carbon black (N774), were also used. Although the presence of the silane coupling agent had not brought the expected increase in properties, treated husk ash showed exceptional performance in terms of tensile strength and abrasion resistance of the filled vulcanizates. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1019–1027, 2000

Leila L. Y. Visconte

Papers

Flame retardancy in thermoplastic polyurethane elastomers (TPU) with mica and aluminum trihydrate (ATH)

Mechanical and dynamic mechanical properties of rice husk ash–filled natural rubber compounds

Life Cycle Assessment of Polyethylene Terephthalate Packaging: An Overview

Mechanical properties of thermoplastic polyurethane elastomers with mica and aluminum trihydrate

The effect of coupling agent and chemical treatment on rice husk ash‐ filled natural rubber composites