| How to reduce the human impact on the environment has been a focus around the world. Today, special attention has been paid on the natural polysaccharide materials, which is owning to their various merits, such as abundant yield and low cost. In this dissertation, we combined the natural polysaccharide materials with flame retardant technology. On one hand, the novel halogen free flame retardant, organic/inorganic hybrid flame retardant has been prepared to investigate its impact on thermal properties and flame retardancy of cotton fabrics. On the other hand, chitosan has been used to synthesize the novel natural resources based flame retardants and study their effect on thermal and combustible properites. The research work of this dissertation is composed of the following parts:1. Two kinds of phosphorus modified siloxane (DIA and PEA) have been synthesized. Then the organic/inorganic hybrid flame retardant coatings were prepared with sol-gel method. They were applied on cellulose fabrics to investigate their effects on thermal properties and flame retardancy. Thermogravimetric analysis (TGA) showed that coatings can improve the thermal stability of cellulose fabrics in high temperature and enhance the residual char. Thermogravimetric analysis/infrared spectrometry (TGA-FTIR) data exhibited that organic/inorganic hybrid flame retardant coatings can reduce the flammable volatile degradation product. The combustion performance was examined by the microscale combustion calorimeter (MCC). Its resultes showed that the heat release rate decreased with the increase of the content of coatings. The result of LOI indicated that coatings improved the flame retardancy of cellulose fabircs.2. Ferric pyrophosphate (FePP) was used as additive to study its synergistic effect of thermal degradation on cotton fabrics. MCC, TGA, TGA-IR, Real Time Fourier transform infrared spectroscopy (RT-FTIR) and Raman spectroscopy were utilized to evaluate the synergistic effects of FePP on DIA/cotton. TGA results showed that presence of FePP improved the thermal stability of materials after300℃. The MCC results revealed that FePP/DIA/cotton generated less combustion heat during heating than that of DIA/cotton. TGA-FTIR results showed that FePP can delay the thermal degradation process. RT-FTIR data revealed the mechanism of the influence of FePP, which can catalyze the break of the flame retardant as well as promote the char forming. 3. A novel nature material based flame retardant melamine chitosan phosphate (MPCS) has been prepared with chitosan, phosphorus pentoxide and melamine. Its impact on thermal properties and flammability performance of polyvinyl alcohol (PVA) was analyzed. Thermogravimetric analysis data exhibited that MPCS enhanced the thermal stability of materials at high temperature as well as the residual char at700℃. RT-FTIR revealed that MPCS promoted the thermal degradation of materials at a lower temperature and accelerated the char forming at high temperature. MCC was used to evaluate the combustion properties. The results showed that peak heat release rate (PHRR), total heat release (THR) and heat release capacity (HRC) all reduced.4. Nickel chitosan phosphate (NiPCS) has been prepared, which was the combination of flame retardant and synergist. Its effect on thermal properties and flammability of PVA has been investigated. MCC test proved that NiPCS can decrease the PHRR and THR greatly. TGA results indicated that NiPCS possessed a high formation of char. With the increase of the flame retardant, the thermal stability of materials enhanced at high temperature. RT-FTIR data confirmed that the flame retardant can promoted the dehydration effect as well as accelerated the char forming. The volatilized products and the synergistic effect of nickel on thermal properties were both investigated with TGA-FTIR and laser Raman spectroscopy (LRS). The results revealed that nickel restained the thermal degradation of materials as well as improved the structural organization level of char.5. Chitosan phosphate acrylate (GPCS) containing phosphorus and acrylate structure has been prepared. Its effect on flammability and thermal properties of epoxy acrylate (EA) has been investigated. MCC data showed that addition of20wt%GPCS reduced56%PHRR. Investigation of RT-FTIR and TGA-IR revealed that GPCS promoted the formation of char and reduced the release of combustible gas. Thermomechanical properties results showed that the storage modulus of samples increased then decreased with increasing GPCS content while the glass transition temperature showed the inverse trend. |
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