PVA厂乙酸甲酯水解回收系统全流程模拟

本文应用HYSYS~等流程模拟软件模拟PVA厂乙酸甲酯(MeOAC)水解回收工序的全流程,分别模拟比较传统的固定床水解工艺、工业化的催化精馏水解工艺和本项目研究的萃取精馏与催化精馏耦合水解工艺。综合工艺流程的模拟,为了降低能耗,提出耦合水解工艺的中试方案:控制回流进料比约为3,进料水酯摩尔大于5,水解转化率大于90%mol,配合电渗析或连续萃取操作提浓乙酸,可望比原固定床工艺节能2成。通过中试反馈和进一步仿真,优化MeOAC水解耦合工艺流程体系,提出实现"深度水解"和"完全水解"的耦合水解工艺新方案,核算过程。结果表明耦合水解工艺方案可行,节能效果十分显著。     

Defensive secretion of rice bug,Leptocorisa oratorius fabricius, (Hemiptera: Coreidae): A unique chemical combination and its toxic,repellent, and alarm properties

Defensive secretion produced by adult males and females ofLeptocorisa oratorius, Fabricius (Hemiptera: Coreidae) living on the host plant,Oriza sativa, was analyzed by a combined gas chromatography-mass spectroscopy technique. Both male and female secretions consisted of two major components: (E)-2-octenal andn-octyl acetate, 76% and 16% (w/w), respectively. The remaining 8% were trace compounds, some of which were identified as hexyl acetate, 3-octenal, 1-octanol, and (Z)-3-octenyl acetate. In a survey among 38 coreid defensive secretions, (E)-2-octenal andn-octyl acetate were found to occur rarely in addition to coreid-specific compounds, while their combination as primary constituents was found to be unique. Toxicity and repellency of this secretion were evaluated using two household pests,Anoplolepis longipes andSitotroga cerealella, as test insects, and lethal concentration (LC₅₀) values of 0.24 ppm and 0.14 ppm, respectively, and repellencies of 63% and 58%, respectively, were obtained. Comparing the above values with those of a pentatomid bug,Coridius janus, evaluated under the same conditions, it was apparent that this secretion has potential as a repellent to enemies ofL. oratorius but not as a toxicant to attack them. Bioassay on the alarm activity of this secretion revealed that it elicits alarm responses, alerting and dispersing aggregated male and femaleL. oratorius: this is followed by self-coating activities. In addition, some unique behaviors were also noted among alarmedL. oratorius.     

LDPE／EVA／CPE并用微孔鞋底料的研制

采用模压法研究了化学交联LPDE/EVA/CPE并用微孔鞋底料的制造方法,着重讨论了LDPE/EVA/CPE并用比,不同种类的橡胶改性剂以及发泡剂、交联剂、填充剂用量对微孔鞋底物理机械性能的影响。实验结果表明,采用国产原料CPE,当LDPE:EVA:CPE=50:30:20时,并配以超细碳酸钙20份和其他助剂,可制得性能较好的微孔鞋底材料。     

硅胶负载硫酸催化酯化反应研究

用热浓硫酸处理硅胶,制备了硅胶负载硫酸催化剂,用冰乙酸与异戊醇的酯化反应考察了催化剂的催化效果。结果表明,该催化剂经多次使用,仍具有良好的催化性能。当催化剂用量为2g,酸与醇的摩尔比为2.61时,4次合成乙酸异戊酯产率平均达到70.6%,与相同条件下浓硫酸催化效果相当。     

纳米碳纤维掺杂量与取向对纳米碳纤维/乙烯-醋酸乙烯酯复合材料介电性能的影响

通过微波法化学镀镍对纳米碳纤维(CNFs)进行表面改性,采用熔融共混法将表面改性的CNFs与乙烯-醋酸乙烯酯(EVA)复合制备CNFs/EVA复合材料,在模压交联过程中对复合材料施加磁场,使表面镀镍的CNFs在复合材料基体中沿磁场方向取向;用场发射扫描电子显微镜(FE-SEM),透射电子显微镜(TEM)和X射线衍射仪(XRD)观察表面改性前后CNFs表面形貌和结构、复合材料内部微观结构及取向情况;用宽频介电谱仪与阻抗谱仪对复合材料进行介电谱测试,研究了CNFs的取向与掺杂量对复合材料介电性能的影响,并用四探针法测量复合材料的体电阻率。研究结果表明,掺杂量和是否取向对复合材料介电性能影响较大;CNFs掺杂质量分数为0.5%时,取向复合材料相对介电常数最低,施加磁场取向不会增加复合材料的介电损耗,少量掺杂即可大幅降低复合材料的体电阻率。     

SBS与醋酸乙烯酯本体接枝物的合成

以过氧化苯甲酰为引发剂,醋酸乙烯酯为溶剂,在无氮气保护下,合成得到了主链为SBS支链为PVAC的接枝共聚物SBS-g VAC,其结构被红外光谱所证实;讨论了引发剂、时间、温度及SBS用量对接枝反应的影响。     

无溶剂微波辐射醋酸铵催化合成肉桂酸

以苯甲醛为原料,醋酸铵为催化剂,经Knoevenagel反应,采用微波辐射技术,在无溶剂条件下合成了肉桂酸。先研究了不同功率和时间下缩合反应的产率,然后用单因素试验法考察了苯甲醛与丙二酸的摩尔比、催化剂用量对反应的影响,得到反应的最佳条件:n(丙二酸)∶n(醋酸铵)∶n(苯甲醛)=1.1∶1.0∶1,微波功率640W,反应时间6min,肉桂酸产率为84.5%。     

VAc／MMA半连续乳液共聚合的研究：Ⅰ种子乳液共聚合

以过硫酸铵为引发剂，十二烷基硫酸钠为乳化剂，于７０℃下进行了ＶＡｃ＝ＭＭＡ种子乳液共聚合。试验考察了组分和操作条件对体系稳定性，聚合速度及组成分布等的影响，同时，从理论上给出了加料速率与体系稳定性因子间的关系。     

醋酸纤维素化学结构对反渗透膜性能的影响

由于纤维素化学结构的特殊性，不同工艺条件制备的醋酸纤维素，即使平均聚合度和酯化度相同的成品，因其乙酰基和羟基在纤维素大分子及基环中分布均一性的差异，会导致所铸反渗透膜水通量和脱盐率的不同。