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- 저자 : Mangeng Lu (검색결과 3 건)
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Tengfei Shen,Mangeng Lu,Liyan Liang 한국고분자학회 2012 Macromolecular Research Vol.20 No.8
A series of novel biodegradable blocked polyurethane crosslinkers (BPUCs) were synthesized from the reaction of toluene 2,4-diisocyanate (TDI), isophorone diisocyanate (IPDI), polycaprolactone (PCL), 1,1,1-trimethylolpropane (TMP), and methyl ethyl ketoxime (MEKO). Synthesis of the accurate kind of BPUCs was confirmed by Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H NMR), and gel permeation chromatography (GPC). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to determine the deblocking temperatures of the BPUCs. The thermal analysis revealed that both TDI- and IPDI-based BPUC had the proper initial deblocking temperature (<160 oC) and the maximum deblocking temperature (<200 oC) for practical applications. Compared to IPDI-based BPUC, the TDI-based BPUC had a lower thermal dissociation temperature and a faster deblocking rate. Hydroxyl polyurethane (HPU) was introduced to study the crosslinking effect of prepared BPUCs. The reaction proceeded at various deblocking temperatures in different curing times. It was noticed that the elastic modulus and tensile strength of the HPU sample increased whereas elongation at break decreased with the addition of BPUC in comparison with pure HPU, which suggested better interfacial adhesion due to the strong chemical reaction between the released NCO groups from BPUC and hydroxyl groups from HPU. In addition, improvement on water resistance of the BPUC modified HPU samples compared to pure HPU samples also demonstrated the good crosslinking effect of prepared BPUCs.
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Chang-An Xu,Mangeng Lu,Kun Wu,Jun Shi 한국고분자학회 2020 Macromolecular Research Vol.28 No.11
Polyurethane (PU) elastomer has been widely used in many fields. In this work, polyurethane/polysiloxane elastomers are synthesized by one-step polymerization using polyether and polyester polyols. The properties of polytetramethylene ether glycol (PTMG) and polycarbonate (PCDL) on polyurethane/polysiloxane elastomers are characterized by various test methods. The results show that PTMG is superior to PCDL in heat resistance and hydrophobicity to polyurethane/polysiloxane elastomers. The heat resistance index of PTMGPU is as high as 154 °C, and its contact angle has reached 115.2°. In addition, the surface of PTMGPU contains more silicone. This may be because the chain structure of PTMG is conducive to the migration of siloxane to the surface, and then a Si-O-Si protective layer is formed, thereby improving the heat resistance and hydrophobicity of the surface of PTMGPU. PCDLPU shows good mechanical properties, which may be related to the stronger chain structure of PCDL. This provides a theoretical basis for the future application of polyurethane/polysiloxane materials.
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Jian Zheng,Yan Zhang,Ying Wang,Jianqun Gan,Lu Shen,FuBin Luo,Liyan Liang,Kun Wu,Mangeng Lu 한국고분자학회 2016 Macromolecular Research Vol.24 No.5
A lateral phthalonitrile functionalized main-chain polybenzoxazine precursor has been successfully synthesized. The structure was characterized by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR). The formation of benzoxazine rings were confirmed by the characteristic resonances observed at about 4.55 (C-CH2-N) and 5.30 ppm (N-CH2-O) and the absorbance at 950 cm-1 of benzene attached with an oxazine ring. The curing behavior was monitored by differential scanning calorimetry (DSC) and in situ FTIR. The completion of polymerization was proved by the disappearance of the band located at 950 cm-1 in FTIR. Thermogravimetric analysis (TGA) was used to investigate the thermal stability, and the results indicated that the thermal stability of the cured polymer gained significant improvement than that without phthalonitrile functionalization.
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