TY - JOUR
T1 - Effects of organoclay modifiers on the flammability, thermal and mechanical properties of polycarbonate nanocomposites filled with a phosphate and organoclays
AU - Feng, Jie
AU - Hao, Jianwei
AU - Du, Jianxin
AU - Yang, Rongjie
PY - 2012/1
Y1 - 2012/1
N2 - Polycarbonate was melt blended with solid bisphenol A bis(diphenyl phosphate), and a series of organoclays. Effects of the organoclay modifiers on the flammability, thermal and mechanical properties of the nanocomposites were studied by limiting oxygen index, UL-94 burning test, thermogravimetric analysis, differential scanning calorimetry, tensile test and dynamic mechanical analysis. Although all the nanocomposites exhibit an intercalated-exfoliated morphology, they vary in the magnitude of intercalation revealed by X-ray diffraction and transmission electron microscopy. Flammability of the nanocomposites is strongly related to the thermal stability rather than the morphology. Glass transition temperature (Tg) and mechanical properties are controlled by both the morphology and the affinity of the organoclays with the matrix. The modifier containing hydroxyl moiety has stronger interactions with the matrix but it can promote its degradation, thus the corresponding nanocomposite exhibits a better intercalated morphology, higher Tg, superior strength and modulus however a worse thermal stability and flame retardancy. An additional silane within the organoclays would make the organoclays more compatible with the matrix but be a steric obstacle to the intercalation of the matrix chains; however, flame retardancy of the corresponding nanocomposite is enhanced due to the flame retardant nature of the silane. Similarly, the modifier bearing two long alkyl tails shows stronger affinity with the matrix than the one bearing a single tail, but it would hinder the intercalation due to the steric effect. These establishments between organoclay modifiers and the properties of nanocomposites might be guidance for developing materials with practical applications.
AB - Polycarbonate was melt blended with solid bisphenol A bis(diphenyl phosphate), and a series of organoclays. Effects of the organoclay modifiers on the flammability, thermal and mechanical properties of the nanocomposites were studied by limiting oxygen index, UL-94 burning test, thermogravimetric analysis, differential scanning calorimetry, tensile test and dynamic mechanical analysis. Although all the nanocomposites exhibit an intercalated-exfoliated morphology, they vary in the magnitude of intercalation revealed by X-ray diffraction and transmission electron microscopy. Flammability of the nanocomposites is strongly related to the thermal stability rather than the morphology. Glass transition temperature (Tg) and mechanical properties are controlled by both the morphology and the affinity of the organoclays with the matrix. The modifier containing hydroxyl moiety has stronger interactions with the matrix but it can promote its degradation, thus the corresponding nanocomposite exhibits a better intercalated morphology, higher Tg, superior strength and modulus however a worse thermal stability and flame retardancy. An additional silane within the organoclays would make the organoclays more compatible with the matrix but be a steric obstacle to the intercalation of the matrix chains; however, flame retardancy of the corresponding nanocomposite is enhanced due to the flame retardant nature of the silane. Similarly, the modifier bearing two long alkyl tails shows stronger affinity with the matrix than the one bearing a single tail, but it would hinder the intercalation due to the steric effect. These establishments between organoclay modifiers and the properties of nanocomposites might be guidance for developing materials with practical applications.
KW - Flame retardancy
KW - Glass transition temperature
KW - Mechanical properties
KW - Polycarbonate nanocomposites
KW - Thermal degradation
UR - http://www.scopus.com/inward/record.url?scp=82755165121&partnerID=8YFLogxK
U2 - 10.1016/j.polymdegradstab.2011.09.019
DO - 10.1016/j.polymdegradstab.2011.09.019
M3 - Article
AN - SCOPUS:82755165121
SN - 0141-3910
VL - 97
SP - 108
EP - 117
JO - Polymer Degradation and Stability
JF - Polymer Degradation and Stability
IS - 1
ER -