PET废丝常压醇解工艺研究

以乙二醇(EG)为降解剂,以醋酸锌为催化剂对聚对苯二甲酸乙二醇酯(PET)废丝进行醇解,研究了在常压下醇解反应条件对醇解率、醇解产物回收率的影响,对醇解产物进行了红外(IR)、热重-差示扫描量热(TG-DSC)以及扫描电子显微镜(SEM)分析.结果表明:PET废丝在常压下进行醇解反应,当EG:PET废丝:醋酸锌质疑比为...     

乙烯基三（β-甲氧基乙氧基）硅烷的合成工艺研究

以乙烯基三氯硅烷（ViSiCl3）、甲醇（MeOH）及乙二醇甲醚为主要原料,采用醇解、酯交换两步反应合成了ViSi（OEtOMe）3。确定了其最佳醇解反应条件为：n（ViSiCl3）：n（MeOH）为1：3.6,反应温度为80℃,在此条件下中间体ViSi（OMe）3收率在85%左右;最佳酯交换反应条件为：n（ViSi（OMe）3）：n（乙二醇甲醚）为1：3.6,反应温度为100℃,反应时间为1.5～2.0h,产物ViSi（OEtOMe）3酯交换的单程收率可达到92%。最后采用GC-MS法对最终产物结构进行了表征。     

Catalytic Processes Involving Dihydrogen Complexes and Other Sigma-bond Complexes

The discovery of dihydrogen complexes, L_nM(H₂), pointed to direct transfer of hydrogen from coordinated H₂ ligands to substrates as an operable pathway in catalysis both in homogeneous and heterogeneous systems. Sigma complexes, L_nM(η²-H–X) (X=H, Si, C, etc), are indeed relevant in hydrogenation as well as silane alcoholysis and methane conversion.     

Enzymatic synthesis of medium‐chain triacylglycerols by alcoholysis and interesterification of copra oil using a crude papain lipase preparation

We have examined the possibility of producing analogs of medium‐chain triglycerides (MCT) from copra oil, i.e. a triacylglycerol mixture with a high content of medium‐chain fatty acid moieties (C₆–C₁₀). A two‐step enzymatic process was used in which copra triacylglycerols were first split with papain lipase by alcoholysis with an alkyl alcohol and then subjected to interesterification with the alkyl esters recovered using papain lipase. Effects of temperature, water activity content, substrate ratio, biocatalyst amount, and alcohol chain length were also investigated. On the one hand, the sn‐3 stereoselectivity of the lipase in the alcoholysis of copra oil with butanol has permitted a direct enrichment of caproic, caprylic and capric moieties in the synthesized butyl esters. Thus, in the batch reactor, the reaction led to about 31% conversion of the oil after 24 h, and the content of C₆–C₁₀ acids in the synthesized esters increased from about 16% in the starting oil to almost 42%. A similar enzymatic alcoholysis in a packed‐bed column bioreactor gave 31% conversion of the oil after 120 min of reactor residence time. The reaction was also very selective because the C₆–C₁₀ fatty acyl groups represented about half of the newly formed butyl esters, whereas they accounted for only 16% of total fatty acids in the starting oil. On the other hand, the transesterification of the alkyl esters recovered (highly enriched in C₆–C₁₀ fatty acyl groups) with native copra oil directly led to an increase in the content of MCT in the oil, from 18 mol‐% at the beginning of the reaction to 61 mol‐% of MCT after a time period of 72 h in the batch reactor.     

苯乙烯膦酸双酯的合成

报道了笔者确定的先用苯乙烯、五氯化磷和二氧化硫制取中间体苯乙烯膦酰二氯，进而用醇将其酯化的工艺路线，报道了试验方法，双酯收率６８％～７２％，产品纯度令人满意     

Response surface analysis for optimisation of reaction parameters of biodiesel production from alcoholysis of Parinari polyandra seed oil

Availability of information on the efficiency of applied conditions to biodiesel synthesis from diverse seed oil can establish optimal biodiesel yield from favourable reaction variables. The effect of reaction parameters; temperature, time and catalyst amount, were varied on biodiesel yield from alcoholysis of Parinari polyandra oil using potassium hydroxide as catalyst. Maximum biodiesel yield of 95.62% was obtained from the experimental results. Analysis of Variance revealed that the reaction variables had significant effects on biodiesel yield. Data analysis predicted an optimal biodiesel yield of 92.75% at reaction conditions of 61.20°C temperature, 60 min, and 1?wt% of catalyst amount. Validation experiments of the optimal conditions gave an average biodiesel yield of 91.72%. The study established optimal conditions of temperature, time, and catalyst amount for biodiesel production from P. polyandra oil. The fuel properties of the biodiesel fell within the standards of the American Society for Testing and Materials D6751.     

Innovation in solid heterogeneous catalysis for the generation of economically viable and ecofriendly biodiesel: A review

Among the possible options for the transformation of plant oils and animal fats to biodiesel, the alcoholysis process has been frequently selected. The rate of alcoholysis reaction is accelerated using a catalytic material. This article reviews different nature of catalysts utilized to assist the process of biodiesel production. The chemical properties of both homogeneous and heterogeneous catalysts enable their sub-division into acidic and basic materials. The proficiency of several heterogeneous catalytic systems and the possible route of alcoholysis reaction using different materials is systematically discussed. Furthermore, the factors influencing the performance of catalysts are also considered.     

聚对苯二甲酸乙二醇酯/SrAl2O4:Eu2+,Dy3+含杂纤维醇解及其回收产物性能

为提高废弃含杂纤维的回收率,以废弃的聚对苯二甲酸乙二醇酯基含杂纤维(PET/SrAl₂O₄:Eu²⁺,Dy³⁺)为研究对象,采用乙二醇醇解联合热乙醇的方法,探究含杂纤维的醇解性能并回收发光材料SrAl₂O₄:Eu²⁺,Dy³⁺及PET醇解产物对苯二甲酸双羟乙酯。通过改变乙二醇用量、反应温度及反应时间探讨乙二醇醇解条件对产物性能的影响,借助扫描电子显微镜、X射线衍射仪、差示扫描量热仪、分光光度测色仪、长余辉亮度仪等对醇解产物的微观形貌、物相结构、热稳定性能、余辉性能等进行测试与表征。结果表明：乙二醇用量、反应温度、反应时间和催化剂用量均不会改变发光材料SrAl₂O₄:Eu²⁺,Dy³⁺的物相结构;当反应温度为190℃,反应时间为180 min时,含杂纤维的醇解率达到100%,此时SrAl₂O₄     

用于聚氨酯醇解的磁性固体碱催化剂CaOMgO SrFe12O19

聚氨酯硬泡降解主要选用1,4-丁二醇为主醇解剂,碱金属氢氧化物为助醇解剂,但多元醇对钾钠离子比较敏感,要求钾钠离子的含量少于10×10^-6,否则可能产生凝胶,使产品报废。文章以选用自制的磁性固体碱催化剂不仅具有碱金属氢氧化物的催化效果,同时又避免因钾钠离子过量产生的凝胶,还兼具催化剂重复使用、易于分离等优点。