The Research Of Red Phosphorus Micro-capsulation Flame Retardant Made

In this paper, microcapsule flame retardants were synthesized by encapsulating red phosphorus within the Polyamide-6(PA-6) resin shell through RESS. Their physical properties and fire retardant properties were investigated.Because the solubility of PA-6 in SCF-CO₂ has never been reported at present, by using IR,SEM,Oxygen Exponent, the solubility of coating material PA-6 in supercritical CO₂ was studied at fist, including the effect of temperature, pressure and co-solvents. The results showed that within the range the equipment could reach, the solubility of PA-6 in SCF-CO₂ was increased with the temperature and the pressure's rose. The influence of temperature on solubility was small, there was no solubility of PA-6 when the temperature was below 20℃. Pressure is the main cause to the solubility of PA-6. Between 15MPa-35MPa, the solubility could increase 60%. The effect of co-solvents to the solubility of PA-6, including ethanol, cardinal, acetone and composite co-solvent (ethanol and acetone) were studied too. Between those co-solvents, the composite co-solvent increased the solubility of PA-6 most, next was ethanol and then was cardinal. According to the result of solubility experiment, microcapsule flame retardants were prepared by RESS, under the condition of 35MPa and 413K. The IR shows that there was absorb peak at 3319cm-1, which is the characteristic peak of the structure of N-H and absorb peak at 1644cm-1, which is the characteristic peak of the structure of C=O. Also there was a clear coating layer on the SEM picture of red phosphorus microcapsule.After adding the Red Phosphorus Micro-capsulation Flame Retardant to the polypropylene (PP), the flame retardant and physical properties of red phosphorus microcapsule flame/PP system were investigated. The results showed that: red phosphorus flame retardant/PP system flame retardant property is prior to red phosphorus/PP and pure PP. Add red phosphorus microcapsule retardant to PP could improve impact strength and reduce tensile-strength slightly.