Effect of a novel chitosan-based flame retardant on thermal and flammability properties of polyvinyl alcohol
- PDF / 429,603 Bytes
- 6 Pages / 595.276 x 790.866 pts Page_size
- 83 Downloads / 255 Views
Effect of a novel chitosan-based flame retardant on thermal and flammability properties of polyvinyl alcohol Shuang Hu • Lei Song • Haifeng Pan Yuan Hu
•
Received: 8 December 2011 / Accepted: 4 September 2012 / Published online: 21 September 2012 Ó Akade´miai Kiado´, Budapest, Hungary 2012
Abstract A novel natural carbon agent-based flame retardant urea salt of chitosan phosphate (UPCS) has been prepared with chitosan, phosphorus pentoxide, and urea. It was characterized by 13C NMR, 31P NMR, Fourier transform infrared spectra (FTIR), and X-ray photoelectron spectroscopy. Its influence on thermal properties and flammability performance of polyvinyl alcohol was investigated through thermogravimetric analysis, microscale combustion calorimetry experiment, and real time FTIR. The surface morphology of the residual char was investigated with the scanning electron microscope measurement. The results revealed that UPCS accelerated the dehydration action as well as the formation of char. Furthermore, flammability performance of polyvinyl alcohol was improved by the presence of UPCS. Keywords Chitosan Flame retardant Thermal properties Flammability
Introduction The intumescent flame retardant system arouses a great interest in recent years because of its efficiency and halogen-free characteristic. It is well established that the intumescent system is mainly composed of an inorganic acid or a material yielding acidic species at temperature between 100 and 250 °C, a carbon agent, and a component that decomposes at the right temperature and at the right time to
S. Hu L. Song H. Pan Y. Hu (&) State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei 230026, Anhui, People’s Republic of China e-mail: [email protected]
enable the blowing of the system [1]. The effectiveness of the intumescent flame retardants is due to the foamed char formed on the surface of the burning material. Char is a carbon-based soot/residue that undergoes very little oxidative degradation, isolates the material from heat and flames, and prevents the fuel molecules from being transported to the combustion surface. Therefore, carbon agent, which affects the formation of char, plays an important role in the intumescent system. A number of researches have been done on searching for environmental-friendly and sustainable carbon agent [2–7]. But these materials are just applied as char former agent additives alone in these investigations. In order to enhance the efficiency on flame resistance, it is useful to prepare flame retardant combined with acid agent, carbon agent, and blowing agent. Chitosan is produced commercially by deacetylation of chitin, which is the structural element in the exoskeleton of crustaceans (such as crabs and shrimp) and cell walls of fungi. It has been a focus in different areas owing to its renewable property, non-toxicity, high biocompatibility, and abundant yield. It should be noticed that multihydroxyl groups are in the structure of chitosan, which is benefit to pr
Data Loading...
