共查询到19条相似文献,搜索用时 312 毫秒
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提纯长叶烯的一种新方法 总被引:1,自引:0,他引:1
用S.Alunni的方法研究了长叶烯、石竹烯和长叶蒎烯等化合物的Vilsmeier-Haack甲酰化反应,并用气相色谱比较了它们的反应速度,从而发现一种利用Vilsmeier-Haack甲酰化反应来提纯长叶烯的新方法。用该法可得84%以上纯度的长叶烯。 相似文献
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为了降低实际生产时中间馏分对高纯度长叶烯单离的影响,对重质松节油单离长叶烯过程中的中间馏分质量分数进行监测,并测定产品的相对密度和折光指数,实验结果表明:长叶蒎烯、长叶环烯存在于整个长叶烯单离过程,长叶蒎烯的影响显著高于长叶环烯。在操作压力-0.1 MPa、塔釜温度150 ℃、回流比1∶7条件下对重质松节油进行精馏,在精馏过程中可通过调整回流比或降低塔釜温度的方式最大程度降低中间馏分对长叶烯质量分数的影响。当塔顶馏出液的d20位于0.926 0~0.926 3时,调整回流比为1∶10或当塔顶馏出液中长叶烯质量分数超过30%后,塔釜温度降低至140~145 ℃之间,当塔顶馏出液d20>0.933 5时,塔釜温度再升至150 ℃。这两种方式均可获得90%以上长叶烯,并且长叶蒎烯、长叶环烯质量分数总和低于1.5%。 相似文献
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乐昌含笑叶挥发油超声波提取工艺优化及化学成分分析 总被引:2,自引:1,他引:1
乐昌含笑具有抗氧化活性,为阐明其作用机理,该文对乐昌含笑叶挥发油进行了提取工艺及化学成分研究。采用超声波法提取挥发油,用正交设计实验优化了各提取参数。萃取的优化条件为V(正戊烷)∶V(乙醚)=1∶2为萃取剂、m(萃取剂)/m(样品)=10、超声时间30 m in。在优化条件下,其挥发油的收率为2.48%。用毛细管气相色谱-质谱联用法结合计算机检索对挥发油化学成分进行了分析和鉴定,从乐昌含笑叶挥发油中共鉴定出42种成分。用气相色谱峰面积归一法测定了各化合物的相对质量分数,占总峰面积的88.66%。乐昌含笑叶挥发油主要成分为大根香叶烯A(10.53%)、(E,E)-金合欢醇(7.53%)、β-丁香烯(6.44%)、α-没药醇(6.16%)、β-榄香醇(6.14%)、莪术烯(4.28%)、长叶烯酮(3.50%)、α-荜澄茄烯(3.25%)和γ-杜松烯(3.23%)。 相似文献
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以重质松节油(主要成分长叶烯和β-石竹烯)和马来酸酐为原料,过氧化二叔丁基为引发剂,环己酮为溶剂,合成了重质松节油-马来酸酐共聚物(HTPMA)。通过气相色谱对由重质松节油与马来酸酐本体自由基聚合所得滤液进行分析,可知β-石竹烯与马来酸酐的反应活性比长叶烯高。通过红外光谱,凝胶色谱,元素分析和热重分析对HTPMA的结构和性能进行了表征。采用2-羟基乙基丙烯酸酯对HTPMA进行改性,得到可UV固化的端乙烯基聚酯(HTMHA)。红外光谱分析表明HTPMA的酸酐基团打开,成功引入了端乙烯基团。对HTMHA紫外光固化膜的性能进行了测试,结果表明固化膜具有较好的柔韧性和耐化学品性。 相似文献
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采用水蒸气蒸馏法提取野菊花挥发油,利用气相色谱-质谱法(GC-MS)测定挥发油化学成分,同时结合直观推导式演进特征投影法解析重叠色谱峰,并采用总体积积分法进行定量。鉴定出66种化合物,占总含量的75.32%,主要成分为石竹烯氧化物、匙叶桉油烯醇、6-isopropenyl-4,8a-dimethyl-1,2,3,5,6,7,8,8a-octahydro-naphthalen-2-ol和反式长松香芹醇。安徽产野菊花挥发油的化学成分主要为单萜烯类、倍半萜烯类及其含氧衍生物等。采用GC-MS联用技术结合直观推导式演进特征投影法分析安徽产野菊花挥发油,提高了定性定量结果的准确性。 相似文献
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用超临界CO2萃取荷花玉兰叶挥发油,对影响萃取效果的各因素用正交设计实验进行了优化。各因素影响大小的顺序为:温度>压力>时间。萃取的优化条件为:压力25 MPa,温度40℃,时间60 min。在最佳条件下荷花玉兰叶挥发油的收率为2.92%。用毛细管气相色谱-质谱联用法结合计算机检索对其化学成分进行了分析和鉴定,结果显示,从荷花玉兰叶挥发油中鉴定出了28种化合物。用气相色谱峰面积归一法测定了各组分的相对质量分数,总计占总峰面积的91.86%,其主要成分为:β-榄香烯(相对质量分数,下同,18.81%)、大根香叶烯D(8.13%)、β-丁香烯(7.18%)、植醇(7.18%)、大根香叶烯B(6.53%)、丁香烯氧化物(5.27%)、9,12,15-十八碳三烯酸乙酯(4.13%)和9,12-十八碳二烯酸乙酯(4.09%)。 相似文献
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以重质松节油通过精馏得到的长叶烯半成品为原料,通过催化反应降低原料中的β-石竹烯含量,制备含量为80%、85%、90%(色谱检测)的高纯度长叶烯产品,收率可达到97.0%。 相似文献
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Youqi Li Xiaopeng Chen Linlin Wang Xiaojie Wei Weijian Nong Xuejuan Wei Jiezhen Liang 《中国化学工程学报》2023,53(1):155-169
The vapor–liquid equilibrium(VLE) data of a-pinene + camphene + [abietic acid + palustric acid + neoabietic acid] and a-pinene + longifolene + [abietic acid + palustric acid + neoabietic acid] systems at 313.15 K,333.15 K and 358.15 K were measured by headspace gas chromatography(HSGC). These data was compared with the predictions value by conductor-like screening model for realistic solvation(COSMO-RS).Moreover, the calculated data of COSMO-RS and Non-Random Two-Liquids(NRTL) models showed good... 相似文献
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Justin H. Dingle Stephen Zimmerman Alexander L. Frie Justin Min Heejung Jung 《Aerosol science and technology》2019,53(4):449-463
Refractive index and optical properties of biogenic and anthropogenic secondary organic aerosol (SOA) particles were investigated. Aerosol precursors, namely longifolene, α-pinene, 1-methylnaphthalene, phenol, and toluene were oxidized in a Teflon chamber to produce SOA particles under different initial hydrocarbon concentrations and hydroxyl radical sources, reflecting exposures to different levels of nitrogen oxides (NOx). The real and imaginary components (n and k, respectively) of the refractive index at 375?nm and 632?nm were determined by Mie theory calculations through an iterative process, using the χ2 function to evaluate the fitness of the predicted optical parameters with the measured scattering, absorption, and extinction coefficients from a Photoacoustic Extinctiometer and Cavity Attenuated Phase Shift Spectrometer. Single scattering albedo (SSA) and bulk mass absorption coefficient (MAC) at 375?nm were calculated. SSA values of SOA particles from biogenic precursors (longifolene and α-pinene) were ~0.98–0.99 (~6.3% uncertainty), reflecting purely scattering aerosols regardless of the NOx regime. However, SOA particles from aromatic precursors were more absorbing and displayed NOx-dependent SSA values. For 1-methylnaphthalene SOA particles, SSA values of 0.92–0.95 and ~0.75–0.90 (~6.1% uncertainty) were observed under intermediate- and high-NOx conditions, respectively, reflecting the absorbing effects of SOA particles and NOx chemistry for this aromatic system. In mixtures of longifolene and phenol or longifolene and toluene SOA under intermediate- and high-NOx conditions, k values of the aromatic-related component of the SOA mixture were higher than that of 1-methylnaphthalene SOA particles. With the increase in OH exposure, kphenol decreased from 0.10 to 0.02 and 0.22 to 0.05 for intermediate- and high-NOx conditions, respectively. A simple relative radiative forcing calculation for urban environments at λ?=?375?nm suggests the influence of absorbing SOA particles on relative radiative forcing at this wavelength is most significant for aerosol sizes greater than 0.4?µm.
Copyright © 2019 American Association for Aerosol Research 相似文献