基于植物油中脂肪酸烷基酯含量变化鉴别废弃油脂

采用固相萃取柱净化,气相色谱-质谱联用法测定了6种植物油中脂肪酸烷基酯(包括脂肪酸甲酯和脂肪酸乙酯)的含量,并研究其在植物油煎炸、废弃及废弃油脂精炼等环节中的变化。结果发现,6种植物油中脂肪酸烷基酯的含量均低于30 mg/kg,而植物油在废弃过程中可能会形成大量脂肪酸乙酯,生成量与油脂是否烹饪及废弃物中乙醇含量有关。脂肪酸烷基酯在脱色工艺中不能被去除,但在脱臭中可被去除。因此,可以通过测定植物油中脂肪酸烷基酯含量发现废弃油脂,为废弃油脂的鉴别工作提供新的思路。     

含酯基季铵盐Gemini表面活性剂的合成及应用

综述了含酯基季铵盐Gemini表面活性剂的合成研究进展及在制革工业中的应用,展望了其发展趋势。     

Supercritical fluid fractionation of fatty acid ethyl esters from butteroil

Countercurrent supercritical fractionation of the fatty acid ethyl esters from butteroil has been investigated. The main objective of the present study was to obtain extracts rich in short- and medium-chain fatty acid ethyl esters. To that end, transesterification of the original butteroil was used to transform the triacylglycerols into the corresponding fatty acid ethyl esters. Then, several supercritical fluid extractions were carried out at pressures ranging from 8.9 to 18.6 MPa and at 2 different temperatures (48 and 60°C). The flow ratio of CO₂ to butteroil was 15. Composition and yield of short- and medium-chain fatty acid ethyl esters was evaluated at different extraction conditions. Extracts containing ∼70% short- and medium-chain fatty acid ethyl esters were obtained at 101 bar and 60°C, and can be used as starting material for the production of highly valuable functional lipids.     

窖泥中总酸、总酯和总醛测定方法的研究

窖泥是生产白酒的关键材料,窖泥的成分复杂,主要有醇类、酸类、醛类、酯类、酚类及芳香族化合物等。本研究建立了一种窖泥中总酸、总酯和总醛的快速连续测定方法,该方法所得3种物质的标准曲线线性关系良好,精密度试验相对标准偏差（RSD）值分别为1.81%、1.13%、0.887%,稳定性试验RSD值分别为1.35%、1.22%、0.96%,加标回收率平均值分别为98.10%、98.16%和98.69%。结果表明,该方法适合窖泥中总酸、总酯和总醛的测定,对白酒的窖泥发酵生产起到一定的指导意义。     

不同辛烯基琥珀酸木薯淀粉酯(OSCS)与壳聚糖质量比对OSCS与壳聚糖-ZnO复合薄膜性能的影响

以壳聚糖和辛烯基琥珀酸木薯淀粉酯（OSCS）为主要成膜基质,甘油为增塑剂、纳米ZnO为增强剂,研究不同OSCS/壳聚糖质量比对薄膜的性能变化。首先制备采用石油醚脱脂和碱法提取木薯淀粉,随后将木薯淀粉改性成OSCS。使用溶液共混法制膜,将壳聚糖溶液、OSCS糊化液及纳米ZnO均质混合,然后超声脱气,烘干成膜。分析不同OSCS/壳聚糖质量比对复合膜力学性能、吸水性、水蒸气透过系数和不透明度的影响。当OSCS/壳聚糖的质量比为1:1时,所得膜的力学性能最佳,抗拉强度为13.85 MPa,断裂伸长率为46.57%。吸水性和水蒸气透过系数随着OSCS和壳聚糖的质量比增加呈现上升的趋势,不透明度呈现先下降后上升的趋势,而OSCS/壳聚糖质量比为1.5:1时不透明度最低为1.56 A/mm。红外光谱证明不同OSCS/壳聚糖质量比的薄膜只是通过简单的物理混合,并无新化学键的产生,并且OSCS/壳聚糖的质量比为1:1时,热性能最佳,玻璃态转化温度最高为102.03 ℃。综合研究,OSCS/壳聚糖的质量比为1:1,整体性能较优,为辛烯基琥珀酸淀粉酯与多糖类复合提供理论基础。     

丙烯酸酯改性水性聚氨酯乳液的合成及胶膜性能研究

以异佛尔酮二异氰酸酯（IPDI）、聚碳酸酯二醇（PCDL）、二羟甲基丙酸（DMPA）三乙胺（TEA）、甲基丙烯酸甲酯（MMA）、丙烯酸丁酯（BA）为原料,采用原位乳液聚合法制备水性聚氨酯-丙烯酸酯（WPUA）复合乳液。考察了聚氨酯（PU ）含量、m(MMA):m(BA)、初始-NCO与-OH物质的量之比等因素对WPUA复合乳液及其胶膜性能的影响。结果显示,当w(PU)质量分数为80%、初始n(-NCO):n(-OH)=6.0、w(DMPA)=5%、m(MMA):m(BA)=4:6时,所得WPUA乳液性能稳定,其胶膜吸水率降低至9.80%,相比较未改性的聚氨酯胶膜的吸水率24.75%,其吸水率降低了60.4%;改性胶膜的拉伸强度达到28.9MPa,是未改性聚氨酯胶膜的1.53倍,制备出了性能稳定、具有优异耐水性和物理机械性能的WPUA复合乳液。     

Nucleotide sequences of alcohol acetyltransferase genes from lager brewing yeast,Saccharomyces carlsbergensis

The nucleotide sequences of alcohol acetyltransferase genes isolated from lager brewing yeast, Saccharomyces carlsbergensis have been determined. S. carlsbergensis has one ATF1 gene and another homologous gene, the Lg-ATF1 gene. There was a high degree of homology between the amino acid sequences deduced for the ATF1 protein and the Lg-ATF1 protein (75·7%), but the N-terminal region has a relatively low degree of homology. Southern analysis and contour-clamped homogeneous electric field analysis of Saccharomyces strains suggest that the ATF1 gene is located on chromosome XV in S. cerevisiae and that the Lg-ATF1 gene might originate from the ‘non-S. cerevisiae’ genome of S. carlsbergensis, which is similar to that of S. bayanus and S. pastorianus. The nucleotide sequence data reported in this paper will appear in the DDBJ, EMBL and GenBank data banks with the Accession Numbers D63449 (ATF1) and D63450 (Lg-ATF1).     

Ester base stocks for synthetic lubricants

This paper reports on work on the synthesis and characterisation of mixtures of aliphatic adipates with complex esters based on polyols, adipic acid, and monohydroxy alcohols, in order to formulate new synthetic base stocks. The viscosity and pour point values of these mixtures are higher than those of adipates. Both of these physical properties become greater with the increasing molecular weight of the complex ester or of the ester's concentration in the mixture.     

竹片/环氧乙烯基酯树脂复合材料的界面性能研究

采用不同浓度的碱与不同浓度的硅烷偶联剂对竹片进行表面改性,研究了表面改性对竹片抗拉强度及其复合材料制品界面层间剪切强度的影响。实验结果表明:适当浓度的碱处理改性方法对竹片拉伸强度和竹复合材料界面剪切强度的提高要明显优于KH550改性方法,双重改性对竹片的抗拉强度具有较好的改善效果;通过扫描电镜分析冲击断面破坏方式发现,竹片/环氧乙烯基酯树脂复合材料界面损伤模式主要表现为竹片中竹纤维抽拔断裂、基体断裂、纤维/基体界面脱粘以及剪切分层,界面性能有所改善。     

环境友好润滑剂的研究概况

综述了环境友好润滑剂的定义、种类及应用,介绍了生物降解试验方法的定义、种类以及生态毒性试验方法,概述了环境友好润滑添加剂的发展现状,并对今后的工作提出了建议.