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1.
有机硅改性苯丙乳液流变性能分析 总被引:1,自引:0,他引:1
李忠铭 《江汉大学学报(自然科学版)》2008,36(2):28-31
用旋转粘度计研究了有机硅改性苯丙乳液的流变性能.结果表明:改性乳液为假塑性流体;随着固含量和单体中丙烯酸比例的增加,乳液的表观粘度增大;有机硅八甲基环四硅氧烷(D4)和乙烯基环四硅氧烷(D4V)对改性乳液的表观粘度影响不同. 相似文献
2.
用乙二胺为核,采用发散合成法,通过迈克尔加成反应和氨酰化反应合成3.0代(G)树枝状大分子聚酰胺-胺(PAMAM);采用傅立叶变换-红外光谱仪(FTIR)和核磁共振波谱仪(NMR)对合成产物的结构进行表征研究,并通过氨基滴定法对1代、2代和3代产物研究分析,获得端基(氨基)含量较高的目标产物。 相似文献
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研究了以聚偏氟乙烯(PVDF)和N-异丙基丙烯酰胺(NIPAAm)的接枝共聚物PVDF-g-PNIPAAm作为成膜材料,在纺制温敏PVDF-g-PNIPAAm中空纤维膜前,影响纺丝液流变性能的主要因素.重点研究了共聚物纺丝液的性质,固含量、溶剂和温度等因素对纺丝液流变性能的影响.研究发现,PVDF-g-PNIPAm纺丝液为假塑性流体,流变性能受多种因素影响.随固含量的增加,纺丝液表观粘度显著增加;在相同温度下以NMP为溶剂时,表观粘度要高于以DMAc为溶剂;表观粘度值随温度的升高而降低,在高剪切速率下,纺丝液流动性能对温度的依赖性提高,纺丝受温度影响较大. 相似文献
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本文报道了在相转移催化(PTC)条件下1,2,3-苯并三唑的N-烷基化反应.合成了七个1,2,3-苯并三唑衍生物,实验结果表明:在以PEG800为相转移催化剂,K_2CO_3为硷的固-液PTC条件下,用各种不同的卤代烃为烷基化剂都得到满意的结果.1,2,3-苯并三唑的N-烷基化生成1-位和2-位取代的两种产物.我们比较了固-液和液-液两种PTC方法对生成1-位或2-位取代产物的影响;分离并测定了这些取代产物的红外光谱(IR),~1H核磁共振谱(~1HNMR)和质谱(MM);并对实验的结果进行了讨论. 相似文献
6.
《东华大学学报(自然科学版)》2016,(5)
在聚酯反应过程中加入生物基戊二胺己二酸盐作为改性单体,成功制备出含生物基戊二胺己二酸的聚酰胺酯.采用核磁共振氢谱(1 H-NMR)、异核多重键相关谱(HMBC)、红外光谱(FTIR)以及元素分析对合成的聚酰胺酯结构进行表征.1 H-NMR结果表明,生物基戊二胺己二酸盐与精对苯二甲酸(PTA)的实际配比与投料比基本吻合,反应比较充分.HMBC结果表明,生物基戊二胺链段与PTA链段直接相连,说明加入的生物基戊二胺己二酸盐成功参与了反应.FTIR结果表明,红外光谱图上既有酯类特征峰,又有酰胺类特征峰,进一步说明产物为聚酰胺酯类物质.元素测试结果表明,两种系列聚酰胺酯的实际氮元素含量与理论氮元素含量的比值均为76%~90%,且都与生物基戊二胺己二酸盐的添加量正相关. 相似文献
7.
扩链剂间苯二胺酰基化改性对聚脲性能的影响 总被引:3,自引:0,他引:3
用酰基化方法对二胺扩链剂间苯二胺进行了改性以解决聚脲反应高活性存在的问题。实验以间苯二胺为原料,在冰乙酸和磷酸条件下一步合成新型位阻型酰胺扩链剂二乙酰间苯二胺。并用红外光谱和核磁共振氢谱分析,对其结构进行了表征,确定了合成产物的化学结构。用改性前后的不同扩链剂与端氨基聚醚和4,4’-二苯甲烷二异氰酸酯(MDI)通过二步溶液法合成聚脲,考察扩链剂酰基化改性对聚脲性能的影响。当用改性扩链剂代替原扩链剂合成聚脲时,其凝胶时间大大延长(从13s延长至1min5s),且显示出较高的拉伸强度和断裂伸长率(分别由30.4MPa 13.9%增加到35.7MPa和21.1%)。 相似文献
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应用固相合成方法合成了氯甲基聚苯乙烯(氯球)担载的1-6代聚酰胺-胺(PAMAM)树状分子镍配合物,将此类配合物用用作在无溶剂情况下分子氧氧化环己烯的催化剂,对其催化性能进行了研究.结果表明,此类配合物对环己烯的氧化反应具有较好的催化活性,反应以2-环己烯醇、2-环己烯酮、和7-杂氧二环[4,1,0]环庚烷-2-酮(3)为主要产物.催化剂制备方法简单且可回收和重复利用. 相似文献
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用丙烯酸酯法对二胺扩链剂己二胺进行了改性,合成了位阻型酯胺扩链剂N,N-2-甲基-丙酸甲酯-1,6-己二胺以解决聚脲反应高活性方面存在的问题.用红外光谱、高分辨质谱、氮含量测定等方法确定了合成产物的化学结构.将改性前后扩链剂与端氨基聚醚和4,4’-二苯甲烷二异氰酸酯通过二步溶液法合成聚脲进行了比较.丙烯酸酯法合成的酯胺扩链剂,在结构上2个-CH2CH(CH3)OCOCH3取代了原结构上的两个活泼H原子,本身活性降低,并产生较大空间位阻效应,使得凝胶时间延长,即反应活性降低,且合成的聚脲具备承受一定载荷和拉伸的能力. 相似文献
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以邻苯二甲酸酐,甘油,顺丁烯酸二酸酐(马来酸酐),硬脂酸和苯甲酸等为原料,采用"A_2+B_3+CA_2"反应体系,通过准一锅法(quasi-one-pot)制备了包含碳-碳双键(-C=C-)的超支化大分子单体(HBM).合成HBM的四步反应进程都通过对反应体系的酸值(Av)和羟值(Hv)的实时分析进行控制.将HBM与甲基丙烯酸甲酯等4种丙烯酸单体进行自由基聚合,得到固含量为75%的丙烯酸树脂HSAR-1.用Tu-4法测定其粘度值仅为18~20 s,与固含量为42%的常规丙烯树脂相当.由于超支化单体的引入,HSAR-1的固含量比常规丙烯树脂(固含量42%)增加了78%,而实测的挥发性有机物(VOC)降低了40%.因此,采用HSAR-1制备涂料时,VOC将大幅度降低. 相似文献
11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness. 相似文献
12.
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly. 相似文献
13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。 相似文献
14.
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well. 相似文献
15.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation. 相似文献
16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death. 相似文献
17.
Miao Maosheng 《华南师范大学学报(自然科学版)》2014,(6)
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula- 相似文献
18.
Yang Weitao 《华南师范大学学报(自然科学版)》2014,46(6):137-138
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re- 相似文献
19.
Bernard Kirtman 《华南师范大学学报(自然科学版)》2014,(6)
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that 相似文献
20.
《上海师范大学学报(自然科学版)》2014,(5):550
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with 相似文献