Stannous-acetylacetonate was prepared efficiently and characterized by ^1H NMR and FT-IR. Its catalytic activity for poly（trimethylene terephthalate） （PTT） synthesis was investigated. By this catalyst, the degree ...Stannous-acetylacetonate was prepared efficiently and characterized by ^1H NMR and FT-IR. Its catalytic activity for poly（trimethylene terephthalate） （PTT） synthesis was investigated. By this catalyst, the degree of esterification of pure terephthalic acid was up to 91.7% after reaction at 260 ℃ for 2 h, while the intrinsic viscosity and content of terminal carboxyl groups of the corresponding PTT polymerized at 260 ℃, 60 Pa for 2 h was 0.8816 dL/g and 17 mol/t,respectively. Stannous-acetylacetonate was more active and promising than tetrabutyl titanate and stannous octoate for PTT synthesis.展开更多
Poly（trimethylene terephthalate） （PTT） is an excellent fiber material. Its thermal degradation and isothermal crystalline behaviors were in this study investigated using thermogravimetric analysis （TGA）, thermog...Poly（trimethylene terephthalate） （PTT） is an excellent fiber material. Its thermal degradation and isothermal crystalline behaviors were in this study investigated using thermogravimetric analysis （TGA）, thermogravimetric analysis-Fourier transform infrared spectroscopy （TGA-FTIR） analysis, differential scanning calorimetry （DSC） and X-ray diffraction （XRD）. The thermal degradation mechanism of PTT follows Mclafferty rearrangement principle. The PTTwithintrinsicviscosity（IV） of 0.74 dL/g has a maximum crystallinity of about 55% at 190 ℃, as demonstrated by DSC and XRD measurements consistently.展开更多
Various morphologies of poly（trimethylene terephthalate） （PTT） solution-cast thin films at different crystallization temperatures were investigated by polarized light microscopy （PLM）,atomic force microscopy （...Various morphologies of poly（trimethylene terephthalate） （PTT） solution-cast thin films at different crystallization temperatures were investigated by polarized light microscopy （PLM）,atomic force microscopy （AFM） and transmitted electron microscopy （TEM）.In the range of 110-150 ℃,banded spherulite occurred and banding space gradually decreased along the radial direction from the primary nucleation site.Between 160 and 170 ℃,normal non-banded spherulite was found.Above 170 ℃,banded configuration occurred again.Lamellar growth direction of banded spherulite was determined to the crystal a-axis.展开更多
对PET/PTT共混体系的DSC热分析结果表明,在共混体系中两组分形成各自的晶体,呈现各自的熔点Tm,但两种聚合物各自的结晶过程是彼此受对方影响的。从形态和热力学两方面对共混体系的熔点下降行为进行了解释,根据N ish i-W ang方程的计算结...对PET/PTT共混体系的DSC热分析结果表明,在共混体系中两组分形成各自的晶体,呈现各自的熔点Tm,但两种聚合物各自的结晶过程是彼此受对方影响的。从形态和热力学两方面对共混体系的熔点下降行为进行了解释,根据N ish i-W ang方程的计算结果,PET/PTT共混体系的相互作用能密度和相互作用参数都为负值,表明PET/PTT共混体系在熔融态是热力学稳定的相容体系,在该体系中,PET和PTT分子间存在着密切的相互作用。展开更多
文摘Stannous-acetylacetonate was prepared efficiently and characterized by ^1H NMR and FT-IR. Its catalytic activity for poly（trimethylene terephthalate） （PTT） synthesis was investigated. By this catalyst, the degree of esterification of pure terephthalic acid was up to 91.7% after reaction at 260 ℃ for 2 h, while the intrinsic viscosity and content of terminal carboxyl groups of the corresponding PTT polymerized at 260 ℃, 60 Pa for 2 h was 0.8816 dL/g and 17 mol/t,respectively. Stannous-acetylacetonate was more active and promising than tetrabutyl titanate and stannous octoate for PTT synthesis.
基金the China High-Tech Development 863 Program(No.2007AA03Z217)Guangdong Province Sci,& Tech.Bureau(No.2006B 12401006,06300332,2007A090302040)+1 种基金Guangzhou Sci.& Tech.Bureau(No.2005U13D2031,2007Z2-D2031)Foshan Sci.& Tech.Bureau for financial support of this work.
文摘Poly（trimethylene terephthalate） （PTT） is an excellent fiber material. Its thermal degradation and isothermal crystalline behaviors were in this study investigated using thermogravimetric analysis （TGA）, thermogravimetric analysis-Fourier transform infrared spectroscopy （TGA-FTIR） analysis, differential scanning calorimetry （DSC） and X-ray diffraction （XRD）. The thermal degradation mechanism of PTT follows Mclafferty rearrangement principle. The PTTwithintrinsicviscosity（IV） of 0.74 dL/g has a maximum crystallinity of about 55% at 190 ℃, as demonstrated by DSC and XRD measurements consistently.
基金Funded by the National Natural Science Foundation of China( No.20234020)
文摘Various morphologies of poly（trimethylene terephthalate） （PTT） solution-cast thin films at different crystallization temperatures were investigated by polarized light microscopy （PLM）,atomic force microscopy （AFM） and transmitted electron microscopy （TEM）.In the range of 110-150 ℃,banded spherulite occurred and banding space gradually decreased along the radial direction from the primary nucleation site.Between 160 and 170 ℃,normal non-banded spherulite was found.Above 170 ℃,banded configuration occurred again.Lamellar growth direction of banded spherulite was determined to the crystal a-axis.
文摘对PET/PTT共混体系的DSC热分析结果表明,在共混体系中两组分形成各自的晶体,呈现各自的熔点Tm,但两种聚合物各自的结晶过程是彼此受对方影响的。从形态和热力学两方面对共混体系的熔点下降行为进行了解释,根据N ish i-W ang方程的计算结果,PET/PTT共混体系的相互作用能密度和相互作用参数都为负值,表明PET/PTT共混体系在熔融态是热力学稳定的相容体系,在该体系中,PET和PTT分子间存在着密切的相互作用。
