Poly(m-xylylene adipamide)/poly(ethylene terephthalate)(MXD6/PET) copolymers are synthesized by melt copolycondensation with 1–5 wt% low molecular weight PET oligomers into the MXD6 oligomers at 260 °C.FR-IR and...Poly(m-xylylene adipamide)/poly(ethylene terephthalate)(MXD6/PET) copolymers are synthesized by melt copolycondensation with 1–5 wt% low molecular weight PET oligomers into the MXD6 oligomers at 260 °C.FR-IR and1 H NMR analysis results indicate that the interchange reaction has occurred between MXD6 oligomers and PET oligomers. The thermal behavior of copolymers shows that the melting temperature of MXD6/PET copolymers decreases with the increasing of amount of PET oligomers, while the crystallization temperature accordingly increases. And the equilibrium temperature Tm0 is evaluated to be 251.8 °C for the copolymers with5 wt% PET oligomer adding, which is very close to that of neat MXD6. The tensile and impact strength of MXD6/PET copolymers are significantly improved than that of pure MXD6 by mechanical properties test, and the microfibril structure in the impact fracture sample's surface reveals the feature of ductile fracture.展开更多
Crystal structures of neodymium (III) and dysprosium (III) nitrate complexes with the new ligand N, N’-dimethyl-N, N’-diphenyladipamide (mpaa) has been determined. Both complexes are triclinic with space group Pī, ...Crystal structures of neodymium (III) and dysprosium (III) nitrate complexes with the new ligand N, N’-dimethyl-N, N’-diphenyladipamide (mpaa) has been determined. Both complexes are triclinic with space group Pī, formula [C22H30N5NdO12S]2 1 [C42H54N7DyO14S 2] Mr = 1465.62[1075.48], a = 8.541(1)[9.711(2)], b = 11.915(1)[16.017(3)], c = 15.906(1) [16.686(3)] ?, α =107.22(1)[109.600(1)], β = 98.12(1)[92.50(1)], γ = 99.78(1) [96.22(1)]°, V = 1491.8(2)[2421.7(8)] ?3, Dc = 1.631[1.475] g·cm-3, Z = 1[2], F(000) = 738[1098], μ=0.71073cm-1; R=0.0261[0.0364], wR=0.0611[0.0857] reflections with I>2σ(I). Complex (1) is dinuclear, in which two Nd(III) ions are double-bridged by two mpaa ligands. And Dy(mpaa)2(dmso)(NO3)3 (2) (dmso= dimethylsulfoxide) is a mononuclear complex, in which one of the two C=O groups in MPAA is uncoordinated. In the two above complexes, each Ln(III) ion is nine-coordinated including three bidenate nitrates, one dmso molecule and two carbonyl oxygens from two different mpaa ligands. Neutral monodentate dmso enters the coordination sphere to meet the geometric requirements. When the number of methylene between O=C…C=O in diamides of the type (R1R2NCO)2(CH2)n was increased, the ligand prefers to act as a bridging reagent rather than a chelate.展开更多
文摘Poly(m-xylylene adipamide)/poly(ethylene terephthalate)(MXD6/PET) copolymers are synthesized by melt copolycondensation with 1–5 wt% low molecular weight PET oligomers into the MXD6 oligomers at 260 °C.FR-IR and1 H NMR analysis results indicate that the interchange reaction has occurred between MXD6 oligomers and PET oligomers. The thermal behavior of copolymers shows that the melting temperature of MXD6/PET copolymers decreases with the increasing of amount of PET oligomers, while the crystallization temperature accordingly increases. And the equilibrium temperature Tm0 is evaluated to be 251.8 °C for the copolymers with5 wt% PET oligomer adding, which is very close to that of neat MXD6. The tensile and impact strength of MXD6/PET copolymers are significantly improved than that of pure MXD6 by mechanical properties test, and the microfibril structure in the impact fracture sample's surface reveals the feature of ductile fracture.
基金the Key Laboratory of Organic Synthesis, Jiangsu Province.
文摘Crystal structures of neodymium (III) and dysprosium (III) nitrate complexes with the new ligand N, N’-dimethyl-N, N’-diphenyladipamide (mpaa) has been determined. Both complexes are triclinic with space group Pī, formula [C22H30N5NdO12S]2 1 [C42H54N7DyO14S 2] Mr = 1465.62[1075.48], a = 8.541(1)[9.711(2)], b = 11.915(1)[16.017(3)], c = 15.906(1) [16.686(3)] ?, α =107.22(1)[109.600(1)], β = 98.12(1)[92.50(1)], γ = 99.78(1) [96.22(1)]°, V = 1491.8(2)[2421.7(8)] ?3, Dc = 1.631[1.475] g·cm-3, Z = 1[2], F(000) = 738[1098], μ=0.71073cm-1; R=0.0261[0.0364], wR=0.0611[0.0857] reflections with I>2σ(I). Complex (1) is dinuclear, in which two Nd(III) ions are double-bridged by two mpaa ligands. And Dy(mpaa)2(dmso)(NO3)3 (2) (dmso= dimethylsulfoxide) is a mononuclear complex, in which one of the two C=O groups in MPAA is uncoordinated. In the two above complexes, each Ln(III) ion is nine-coordinated including three bidenate nitrates, one dmso molecule and two carbonyl oxygens from two different mpaa ligands. Neutral monodentate dmso enters the coordination sphere to meet the geometric requirements. When the number of methylene between O=C…C=O in diamides of the type (R1R2NCO)2(CH2)n was increased, the ligand prefers to act as a bridging reagent rather than a chelate.
