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熔融-固相聚合法直接合成聚乳酸的研究 被引量:26
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作者 赵耀明 汪朝阳 +1 位作者 麦杭珍 王浚 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 2002年第11期155-159,共5页
以L_乳酸单体为原料 ,通过熔融 -固相聚合法直接合成聚左旋乳酸 (PLLA) .筛选出SnCl2 为适宜的催化剂进行熔融聚合 ,聚合的最佳工艺条件为 :SnCl2 质量分数为0 .5 % ,180℃、70Pa下反应 10h .以熔融聚合制得的粘均相对分子质量为 5 0 0 ... 以L_乳酸单体为原料 ,通过熔融 -固相聚合法直接合成聚左旋乳酸 (PLLA) .筛选出SnCl2 为适宜的催化剂进行熔融聚合 ,聚合的最佳工艺条件为 :SnCl2 质量分数为0 .5 % ,180℃、70Pa下反应 10h .以熔融聚合制得的粘均相对分子质量为 5 0 0 0的PLLA为原料 ,于 6 0Pa下 ,以SnCl2 为催化剂进行变温固相聚合 (先在 135℃下反应 5h ,再在15 0℃下反应 10h) ,可使粘均相对分子质量提高到反应前的 5 .3倍 . 展开更多
关键词 熔融-固相聚合法 直接合成 聚乳酸 生物降解材料 生产工艺 相对分子质量
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PEDOT的固相聚合法制备及其在紫外光探测器中的应用
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作者 吐尔逊·阿不都热依木 凯丽比努尔·艾孜热提玉麦尔 +2 位作者 唐新生 拿吾尔斯汗·赛尔克江 依力亚尔·吾休 《功能高分子学报》 CAS CSCD 北大核心 2023年第1期51-57,共7页
首先以2,5-二溴-3,4-乙撑二氧噻吩(DBEDOT)为单体,通过固相聚合法在掺杂氟的二氧化锡导电玻璃(FTO)基底表面制备聚(3,4-乙撑二氧噻吩)(PEDOT)膜,然后将其与氧化锌纳米阵列(ZnO NRs)修饰的FTO组装成有机-无机异质结紫外光探测器,并研究... 首先以2,5-二溴-3,4-乙撑二氧噻吩(DBEDOT)为单体,通过固相聚合法在掺杂氟的二氧化锡导电玻璃(FTO)基底表面制备聚(3,4-乙撑二氧噻吩)(PEDOT)膜,然后将其与氧化锌纳米阵列(ZnO NRs)修饰的FTO组装成有机-无机异质结紫外光探测器,并研究其紫外光探测性能。采用紫外-可见分光光谱(UV-Vis)、傅里叶变换红外光谱(FT-IR)、扫描电子显微镜(SEM)、X射线衍射光谱(XRD)等测试方法对材料进行表征。结果表明,固相聚合法制备的PEDOT能有效提升ZnO NRs基紫外光探测器的性能。器件在紫外光照射下(365 nm,0.32 mW/cm^(2))表现出较高响应度(15.34 mA/W)、较短响应时间(上升时间为0.159 s,下降时间为0.162 s)和较好的稳定性。 展开更多
关键词 固相聚合法 聚(3 4-乙撑二氧噻吩) 氧化锌纳米阵列 异质结 紫外光探测器
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TiO_2/BMI 树脂固化反应及热性能研究 被引量:3
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作者 刘祥萱 段少峰 +3 位作者 凌月 杨绪杰 陆路德 汪信 《南京理工大学学报》 EI CAS CSCD 1998年第3期244-247,共4页
利用热分析技术测定了纳米TiO2共混改性双马来酰亚按(BMI)树脂体系的固体反应参数,考察了固化条件与玻璃化温度之间的关系及纳米TiO2对固化树脂高温热分解性能的影响。研究结果表明,树脂中引入纳米TiO2,降低了固化... 利用热分析技术测定了纳米TiO2共混改性双马来酰亚按(BMI)树脂体系的固体反应参数,考察了固化条件与玻璃化温度之间的关系及纳米TiO2对固化树脂高温热分解性能的影响。研究结果表明,树脂中引入纳米TiO2,降低了固化反应活化能和树脂固化后处理温度,改善了BMI树脂的加工性能;树脂在N2中的起始热分解温度降低,但不改变热氧分解温度;TiO2/BMI固化树脂玻璃化温度高达302℃,热分解温度达420℃;在一定温度范围内,提高固化温度和延长固化时间,可使树脂的玻璃化温度显著提高。 展开更多
关键词 聚酰亚胺 固相聚 热稳定性 二氧化钛 化反应
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Preparation and characterization of poly(lithium acrylate-arcylonitrile)/LiClO_4-LiNO_3-LiBr solid polymer electrolytes 被引量:4
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作者 潘春跃 袁云兰 +2 位作者 陈振华 徐先华 张坚 《Journal of Central South University of Technology》 2005年第1期68-72,共5页
Through orthogonal experiment, a new type of LiClO4-LiNO3-LiBr eutectic salt with optimum mole ratio of n(LiClO4)∶n(LiNO3)∶n(LiBr)=1.6∶3.8∶1.0 was prepared. The poly(lithium acrylate-acrylonitrile)/LiClO4-... Through orthogonal experiment, a new type of LiClO4-LiNO3-LiBr eutectic salt with optimum mole ratio of n(LiClO4)∶n(LiNO3)∶n(LiBr)=1.6∶3.8∶1.0 was prepared. The poly(lithium acrylate-acrylonitrile)/LiClO4-LiNO3-LiBr solid polymer electrolytes were prepared with poly(lithium acrylate-acrylonitrile) and (LiClO4-LiNO3-LiBr) eutectic salts. The effect of LiClO4-LiNO3-LiBr eutectic salts content on the conductivity of solid polymer electrolytes was studied by alternating current impedance method, and the structures of eutectic salts and solid polymer electrolytes were characterized by differential thermal analysis, infrared spectroscopy and X-ray diffractometry. The results show that the room temperature conductivity of LiClO4-LiNO3-LiBr eutectic salts reaches (3.11×10-4 S·cm-1.) The poly(lithium acrylate-acrylonitrile)/LiClO4-LiNO3-LiBr solid polymer electrolytes possess the highest room temperature conductivity at 70% LiClO4-LiNO3-LiBr eutectic salts content, and exhibit lower glass transition temperature of 75 ℃ compared with that of poly(lithium acrylate-acrylonitrile) of 105 ℃. A complex may be formed in the solid polymer electrolytes from the differential thermal analysis and infrared spectroscopy analysis. X-ray diffraction results show that the poly(lithium acrylate-acrylonitrile) can suppress the crystallization of eutectic salts in this system. 展开更多
关键词 solid polymer electrolyte CONDUCTIVITY eutectic salt LiClO_4 LiNO_3 LIBR arcylonitrile
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Preparation of poly(amino-quinone) by microwave-assisted solid-state polymerization
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作者 李海普 万俊杰 +1 位作者 王帅 常庆伟 《Journal of Central South University》 SCIE EI CAS 2010年第3期467-471,共5页
Microwave irradiation was employed to assist the synthesis of poly(amino-quinone) (PAQ) from p-benzoquinone and diamines in solid state. The effects of power, time, and pattern (continuously or intermittently) o... Microwave irradiation was employed to assist the synthesis of poly(amino-quinone) (PAQ) from p-benzoquinone and diamines in solid state. The effects of power, time, and pattern (continuously or intermittently) of microwave irradiation on yield and intrinsic viscosity of PAQs were studied. It is shown that the continuous microwave irradiation at a high power leads to rapid increase of yield and a sudden halt in polymerization afterwards, due to the subsequent loss of volatile reactants at a high reaction temperature. Alternatively, the high-power microwave irradiation is applicable to raising the yield if used intermittently. In contras4 the low-power microwave irradiation favours the way of continuous exposure to ensure sufficient heat for polymerization. In both cases of high and low power, the yield and intrinsic viscosity can be further promoted by prolonging the exposure time. It is found that under a preliminarily optimized condition of intermittent irradiation at 490 W with six sequences of 5 min irradiation followed by 5 rain interval, the yield and intrinsic viscosity of PAQ from p-benzoquinone and p-phenylene diamine can reach as high as 83% and 41.9 mL/g, respectively. 展开更多
关键词 poly(amino-quinone) MICROWAVE solid-state reaction
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Microstructure and mechanical properties of Al-6.02Zn-1.94Mg alloy at higher solution treatment temperature
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作者 NIE Chang-chang HUANG Yuan-chun +1 位作者 SHAO Hong-bang WEN Jin-chuan 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第3期937-949,共13页
The effects of solution treatment temperature and holding time on the microstructure and mechanical properties of extruded Al-6.02 wt.%Zn-1.94 wt.%Mg alloy were investigated by differential scanning calorimetry(DSC),o... The effects of solution treatment temperature and holding time on the microstructure and mechanical properties of extruded Al-6.02 wt.%Zn-1.94 wt.%Mg alloy were investigated by differential scanning calorimetry(DSC),optical microscopy(OM), scanning electron microscopy(SEM), X-ray diffraction(XRD), and tensile test. The results showed that the optimum solution treatment process for the alloy was 470 ℃, 2 h. The tensile strength, yield strength,and elongation of the samples after the aging treatment at 120℃ for 24 h were 486 MPa, 431 MPa, and 14.8%,respectively. The alloy produced more copious recrystallization with the augment of solution temperature and the extension of holding time. While the second phase of η(MgZn_(2)), and T(AlZnMgCu) in the matrix was not fully re-dissolved under the treatment condition of lower temperature or shorter holding time. Interestingly, the Zr aggregation was observed in the samples treated at 510 ℃ for 2 h, which led to the growth of the second phase particles and the increase of their area fraction. 展开更多
关键词 MICROSTRUCTURE solution treatment second phase RECRYSTALLIZATION AGGREGATION
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