从雷竹叶中提取茶多酚及其红外光谱的研究

以雷竹叶为原料,按设计的工艺条件,用乙醇提取茶多酚,乙酸乙酯萃取,回收溶剂,大孔树脂精制产物。得到竹叶中的粗茶多酚的含量13.4%,精茶多酚含量为2.60%。以没食子酸为标品、进行提取物及精制茶多酚的红外测试,对其基团归属予以认定,确定产物成分。     

雷竹叶多糖与黄酮的联合提取工艺设计

设计了联合提取多糖与黄酮的新工艺,通过红外光谱鉴定了提取物.竹叶中粗多糖的含量为8.79%,黄酮的含量为26.33 mg/g(竹叶粉).而精制后多糖(BP1)占粗多糖的37.5%,均与单一提取法的文献报道值接近.     

滇产驱蚊香草芳香油化学成分分析研究

采用气相色谱 质谱联用技术对驱蚊香草芳香油成分进行研究 ,共检出 64个组分 ,鉴定出已知化合物 5 9个 ,占芳香油成分总数的 92 .2 %,占总含量的 97.45 %。主要化学成分为 :香叶醇、芳樟醇、香茅醇、异薄荷酮、β 古芸烯、桉醇、γ 木罗烯、异已酸香叶酯、丙酸香叶酯等 ,其中香叶醇占芳香油成分总含量 41.44 %。此外 ,采用气相色谱法 ,按GB115 3 8 85标准 ,在相同条件下 ,对驱蚊香草芳香油与天竺葵精油以及不同产地驱蚊香草的化学成分 ,进行了对比分析研究     

纤维素酶提取竹叶黄酮工艺初步研究

以绵阳师范学院磨家校区附近竹叶为试验对象,采用单因素试验,分别考虑料液比,酶解时间,纤维素酶用量三个因素,进行了纤维素酶辅助提取竹叶总黄酮的最佳提取工艺研究。结果表明：提取料液比1：15（g／mL）,酶解时间为1．5 h和纤维素酶浓度0．5％时,竹叶总黄酮提取效果最佳。此时测得总黄酮的得率为2．17％,在此条件下的验证实验结果表明,该工艺条件有较好的重现性。     

微波辅助提取竹叶黄酮的研究

用微波辐射技术辅助乙醇提取竹叶总黄酮的结果表明,微波辅助萃取的最佳工艺条件为:固液比为1∶25(w/w),溶剂乙醇的体积分数为60%,微波功率为600 W,辐射时间为6 min。在此条件下,竹叶中的总黄酮提取率可达2.93%。     

竹叶中茶多酚的提取及其抗氧化性研究

探讨用超声技术从竹叶中提取茶多酚的最优工艺条件,并对茶多酚的抗氧化性进行研究。以茶多酚的产率为考察指标,通过单因素试验和正交试验确定从竹叶中超声提取茶多酚的适宜工艺条件：超声功率为70W,浸提温度75℃,超声时间40mn,料液比1：20,乙醇体积分数75％,此条件下茶多酚提取产率为0．624300。以Fenton反应、DPPH法检测其清除自由基活性,结果表明,竹叶中茶多酚具有较强的清除羟基自由基的能力,是一种很好的天然抗氧剂。     

从竹叶中提取叶绿素新工艺

本文介绍了竹叶的采集、保鲜及提取叶绿素的工艺过程。     

竹叶提取物的研究及竹叶提取物牙膏的研制

介绍了分析竹叶的传统药用价值、竹叶提取物的成分、功效和安全性,探讨了竹叶提取物在牙膏中的应用,并研制出具消炎抑菌、口气清新的竹叶提取物牙膏。     

竹叶黄酮的提取、纯化及抗氧化性能研究

对竹叶中的黄酮类化合物进行提取、纯化及抗氧化性能研究。考察了大孔树脂对竹叶黄酮的吸附、解吸工艺参数,当黄酮上样量流速为1.0 m L/min,pH为5.0时,黄酮吸附率最高为80.13%。当洗脱剂乙醇流速为1.5 m L/min,乙醇浓度为60%时,黄酮解吸率最佳为90.6%。竹叶黄酮在光照、强酸、强碱条件下,自由基清除率下降明显。     

纤维素酶法提取竹叶黄酮的传质动力学

采用纤维素酶法提取竹叶中的总黄酮类化合物,讨论了温度、原料尺寸、转速及纤维素酶用量对传质速率的影响,并用扫描电镜观察了水提和酶提取后样品的细胞结构变化。结果表明,竹叶黄酮的提取动力学符合平板型Fick第二定律,提取过程主要受内扩散控制;纤维素酶不改变传质动力学机理,它只破坏细胞壁,从而降低扩散阻力使溶质的传质速率和表观扩散系数D′提高。实验还得到了D′与提取温度、竹叶几何尺寸之间的关系,在30～60℃,酶提时的D′为1.95×10 13～6.85×10 13m2·s-1,水提时的D′为1.73×10 13～6.05×10 13m2·s-1;酶提时的活化能Ea为11.853kJ·mol-1,比水提时降低了9.59%。该研究为酶法提取竹叶黄酮的工艺设计及工业化应用提供了理论依据。     

重芳烃油中提取茚类化合物分离工艺探讨

本研究采用顺序切割法对重质芳烃油进行分离研究,通过对分离产物进行检测,表明了从重质芳烃油中提取茚及茚类化合物可行,所得产物用来合成树脂达到预期目的,也为工业企业分从重质芳烃油中获得茚及茚类化合物提出了三塔分离工艺流程设想。     

芳烃油和环烷油对中乙烯基聚丁二烯橡胶性能的影响

研究了不同份数芳烃油及环烷油对中乙烯基聚丁二烯橡胶性能的影响。研究结果表明,随着操作油的份数增大,正硫化时间延长,加入40份炭黑、10份油时胶料的综合性能最好,填充相同份数芳烃油比填充相同份数环烷油胶料的物理性能稍好。     

赤水绵竹叶黄酮提取工艺方法研究

以芦丁为标准品,以贵州省赤水市绵竹叶为实验对象,对竹叶黄酮的提取进行研究,以乙醇浓度、反应温度、料液比、反应时间为主要考察因素,进行L9（3^4）正交实验,对竹叶黄酮提取条件进行系统研究,确定黄酮最佳提取工艺为乙醇提取浓度75％,反应温度70℃,料液比1：20,反应时间5．5h。     

重质芳烃油选择性加氢工艺研究

以油浆抽提得到的重质芳烃油为原料,通过选择性加氢工艺降低其中有害的稠环芳烃(PAHs)化合物,得到的精制油为橡胶用环保芳烃油。实验分别对反应温度、压力、时间以及一段、二段加氢工艺对PAHs转化率的影响进行了考察,同时运用BET及EDS对2种硫化态催化剂进行了表征,以考察催化剂的活性及选择性。结果表明,Ni-W/γ-Al2O3催化剂活性及选择性较Ni-Mo/γ-Al2O3高。实验证明:通过选择性加氢可大幅度降低重质芳烃油中PAHs质量分数,一段加氢采用Ni-W/γ-Al2O3催化剂,在反应温度280℃、压力8 MPa、时间6 h的条件下,原料PAHs转化率达到46.24%;二段加氢采用Ni-Mo/γ-Al2O3催化剂,在与一段相同的反应条件下,PAHs转化率达到32.94%。经2段加氢后,产物中PAHs质量分数由起始的58.13%降到21.05%,总转化率达到63.79%,液体总收率91.72%。     

芳香烃型橡胶填充油的研制

以N-甲基吡咯烷酮和糠醛为溶剂,对新疆混合原油的减压馏分油进行了精制,并对此抽出油进行注水、降温沉降研究及芳香烃型橡胶填充油的放大制备试验研究。结果表明,在沉降温度50℃、注水量2%、沉降时间40 m in的优化工艺条件下,可使抽出油芳香烃质量分数达到80%以上。以此芳香烃型橡胶填充油进行丁苯橡胶的充油试验,其充油丁苯橡胶主要性能良好,300%定伸应力、拉伸强度及扯断伸长率等性能更为优异。     

Stability of refined olive oil and olive‐pomace oil added by phenolic compounds from olive leaves

Refined olive oil and olive‐pomace oil were enriched with olive leaf phenolic compounds in order to enhance its quality and bring it closer to virgin olive oil. The changes that occurred in the concentrations of pure oleuropein, oleuropein aglycone, hydroxytyrosol acetyl and α‐tocopherol at 400 µg/kg of oil during the storage of refined olive oil and olive‐pomace oil under accelerated conditions (50 °C) were investigated. In a period of 4 months, α‐tocopherol decomposed by 75% whereas less than 40% of the phenols were lost. During storage, enzymatic olive leaf extract hydrolysate that contains two major compounds, hydroxytyrosol and oleuropein aglycone showed the highest antioxidant activity and the lowest detected stability, followed by oleuropein. The oleuropein in olive leaf extracts exhibited similar degradation profiles, reducing by 60–50% and 80% for the olive oil and olive‐pomace oil in 6 months, respectively. The acetylated extract, however, displayed a loss of 10 and 5% in olive oil and olive‐pomace oil, respectively. In the fatty acid composition, an increase in oleic acid and a decrease in linoleic acid were observed. The antiradical activities of the olive oil and olive‐pomace oil enriched with olive leaf phenolic compounds at 400 ppm showed that enzymatic hydrolysate extract had the highest protective effect against oil oxidation. Based on the Rancimat method, the oils with added leaf enzymatic hydrolysate extract had the lowest peroxide value and the highest stability. After 6 months of storage and at 120 °C, the oxidative resistance of refined olive oil and olive‐pomace oil reached 0.71 and 0.89 h, respectively, whereas that of the non‐enriched samples fell to zero.     

Supercritical carbon dioxide extraction of spearmint oil from mint-plant leaves

Spearmint oil (essential oil of Mentha spicata) was extracted from Turkish mint-plant leaves using supercritical CO₂ in a basket-type extractor. Effects of temperature, pressure, extraction time, amount of CO₂, and entrainer (ethanol) concentration on composition of essential-oil extracts and oil yield, relative to hydro-distillation, were investigated. Relative yields were as high as 80%. Monoterpenes fraction in extracts was inversely correlated with relative oil yields. Monoterpenes were preferentially extracted by CO₂ due to their high vapor pressure, low molar mass and low polarity. Supercritical extraction presented advantages over the conventional hydro-distillation by yielding extracts lower in monoterpenes fraction and by enabling high yields at temperatures safe for the heat-sensitive essential oil.     

Polyurethanes from soybean oil,aromatic, and cycloaliphatic diamines by nonisocyanate route

Polyurethanes were prepared via a nonisocyanate route, by reacting carbonated soybean oil (CSBO) with aromatic and cycloaliphatic diamines. Nonisocyanate polyurethanes prepared form CSBO and aliphatic diamines have relatively low tensile strength and one of the possible ways to increase strength and rigidity is to use diamines with rigid aromatic or cyclic structure. The effect of amine structure and amine to carbonate ratio on polyurethane structure and mechanical, physical, and swelling properties was studied. m‐xylylene diamine (m‐XDA), p‐xylylene diamine (p‐XDA), and isophorone diamine were used as the reactants, with amine to carbonate ratios of 0.5 : 1, 1 : 1, and 1 : 2. All amines produced elastomeric polyurethanes with glass transitions between ?6° C and 26°C, as measured by differential scanning calorimeter (DSC). T_g was primarily controlled by the amine‐to‐cyclic carbonate ratio, and to a lesser extent by the amine structure. The highest tensile strength was obtained for p‐XDA and the lowest for m‐XDA as a result of differences in hydrogen bonding. Tensile strength and hardness were higher than in aliphatic diamine‐based polyurethanes. Swelling in toluene and water depended on the polarity of polyurethane networks that was dominantly controlled by the amine‐to‐cyclic carbonate ratio. Swelling in toluene was higher at the lower amine to carbonate ratio due to lower polarity of the polyurethane matrix. Swelling in water behaved quite the opposite, the degree of swelling for the more polar polyurethane matrix was higher. Reaction temperatures of 70–100°C were high enough to promote ester group cleavage and along with urethanes, amide formation was always present. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

从松树叶中提取精油的研究

本文用不同的溶剂从若干松树叶样品中提取了精油，采用GC—MS技术分析了所得精油的化学组成。结果表明，不同产地、不同树龄的松树叶中都含有相同组分：α-蒎烯、莰烯、β-蒎烯、α-异松油烯、醋酸冰片酯、反式-丁子香烯、二环大根香叶烯、α-紫穗槐烯、δ-杜松烯、α-杜松烯。其精油分为3种萜烯类：单萜烯、倍半萜烯、含氧萜烯。当水蒸汽蒸留时，所得精油中3种萜烯的含量达到92（wt）％以上。但提取法不同所得精油的主要组成发生变化：水蒸汽蒸馏法所得精油中单萜烯含量为57．7（wt）％；乙醇溶剂提取法所得精油中含氧萜烯含量为75．47（wt）％；丙酮与水混合溶剂提取法所得精油中总萜烯含量为55．4（wt）％。     

环保芳烃油对充油SBR性能的影响

通过对比SBR1723与SBR1712生胶与胶料性能,研究环保芳烃油(TDAE)对充油SBR性能及其在轿车子午线轮胎胎面胶中应用性能的影响.结果表明,由于填充油品不同,SBR1723玻璃化转变温度比SBR1712低2～3 ℃,其混炼胶加工性能稍差,硫化胶拉断伸长率下降,滚动阻力和生热降低,耐磨性较好,抗湿滑性能有所下降.在轿车子午线轮胎胎面胶中应用时,随着补强剂作用的加强,填充油品的影响变小,适当提高白炭黑用量可进一步降低滚动阻力和改善抗湿滑性能.