Improved flame resistance properties of unsaturated polyester resin with TiO2-M O solid superacid

Recent Developments of Nano Flame Retardants for Unsaturated Polyester Resin

For many years, efforts have been made to reduce the flammability of unsaturated polyester resins (UPRs), which are often used in the rail, shipbuilding, and construction industries. Without modification, they often fail to meet fire safety standards. Despite a rich history of flame retardants (FRs) applied to UPRs, researchers seek new solutions that will provide lower flammability and smoke density, as well as attaining a lower environmental impact from the composites. The objective of the study is to highlight the most important recent research on promising nano FRs in order to promote their further development. Mechanisms of action of several groups of nano FRs, such as clay-based, carbon-based, transition metal compounds, layered double hydroxides, polyhedral oligomeric silsesquioxanes, and others, including bio-based, have been studied. Particular emphasis has been laid on nano FRs applied to UPRs, and their influences on thermal stability, flammability, and mechanical properties. Moreover, the environmental impact and toxicity of nano FRs have been discussed. Results have proved that nano FRs applied at low loadings may significantly improve thermal stability, with a simultaneous increase or only a slight decrease in mechanical properties. However, attention on related environmental issues has highlighted the necessity of carefully selecting novel nano FRs.

An environment friendly hemp fiber modified with phytic acid for enhancing fire safety of automobile parts

To overcome the pollution to the environment with the application of flame retardants in automobiles, complete environment-friendly flame retardants have aroused wide concern. Furthermore, natural fibers have replaced artificial fibers in various fields due to their excellent performance and environmentally friendly. Thus, in this work, modified hemp fiber (HF-P) via phytic acid was obtained and used as a green flame retardant for automobile parts containing unsaturated polyester resins (UPR). The flame retardance of UPR composites were tested by thermogravimetric analysis, limiting oxygen index (LOI), and cone calorimeter test. A total of 3 wt% HF-P imparted UPR matrix excellent flame retardancy. The LOI value of UPR/HF-P-3 composites was increased from 18.9% of pure UPR to 22.1%, and the values of AHRR and THR were reduced to 401.9 kW/m2 and 150.6 MJ/m2, respectively. TGA test shows that HF-P can effectively improve the carbon-forming ability of UPR composites, which provides a material basis for condensed phase flame retardancy. For mechanical properties, the incorporation of HP-F endows a better enhancement on flexural strength of UPR composite.

Modification of Glass/Polyester Laminates with Flame Retardants

This paper presents a review of flame retardants used for glass/polyester laminates. It concerns flame retardants withdrawn from use such as compounds containing halogen atoms and flame retardants currently used in the industry, such as inorganic hydroxides, phosphorus and nitrogen-containing compounds, antimony, and boron compounds, as well as tin–zinc compounds. Attention is also drawn to the use of nanoclays and the production of nanocomposites, intumescent flame retardant systems, and mats, as well as polyhedral oligomeric silsesquioxanes. The paper discusses the action mechanism of particular flame retardants and presents their advantages and disadvantages.