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1.
以壬基酚聚氧乙烯醚(OP-10)作乳化剂,十二烷基苯磺酸(DBSA)为催化剂,通过八甲基环四硅氧烷(D4)开环聚合,在一定条件下合成了端羟基聚二甲基硅氧烷微乳液.分析了聚合温度、聚合时间、预乳化时间、乳化剂和催化剂的用量对单体转化率和乳液透光率的影响.确定了最佳合成工艺条件:65℃下反应5h,OP-10和DBSA用量分别为微乳液质量的4%~5%和3%~4%,预乳液滴加时间为1.5~2h.产品为半透明乳液,略泛蓝光,具有优异的稳定性能.  相似文献   

2.
以八甲基环四硅氧烷(D4)作为模型单体,分别使用高速分散机、超声波仪和高压均质机制备了D4细乳液,使用多重光散射稳定性分析仪(MLS)分析比较了不同方法制备的D4细乳液的稳定性,并通过稳定性的分析,研究了均质压力和乳化剂浓度对单体细乳液的稳定性的影响。结果表明,在同样的乳化剂浓度下采用高压均质机制备的细乳液稳定性最好,能够稳定进行细乳液聚合;随着均质压力(10~110 MPa)增大,D4 细乳液的稳定性先增强后减弱,在90 MPa下制备的细乳液稳定性最好,乳液粒径增长速率仅为0.342 nm/min;随着DBSA浓度(0.0092~0.0460 mol/L)增大,在相同均质条件下(90 MPa 下均质4次)制备的单体细乳液稳定性增强,粒径增长速率都小于0.505 nm/min,具有较好的稳定性。  相似文献   

3.
以八甲基环四硅氧烷(D4)为原料,磺酸型双子表面活性剂为乳化剂(兼催化剂),制备了一种新型的有机硅乳液.考察了反应温度、乳化剂的用量、反应时间对乳液体系的粒径、D4的转化率、黏均分子量和力学稳定性的影响.结果表明:采用单体滴加法,在85℃高温聚合8h,然后25℃低温聚合12h,乳化剂用量为单体用量的10%,在此条件下制备的产品为微透明且具有优异稳定性能的乳液,D4转化率较高,该乳液经破乳后得到的聚硅氧烷(PDMS)黏均分子量达到2.38×105g/mol.  相似文献   

4.
以八甲基环四硅氧烷(D4)和N–β–氨乙基–γ–氨丙基甲基二甲氧基硅烷(KH–602)为原料,用(CH3)4NOH作为催化剂,低粘度二甲基硅氧烷为封端剂,采用本体阴离子聚合法合成了侧氨基改性聚硅氧烷,并对其结构用红外光谱与紫外光谱进行了表征.研究了制备过程中聚合时间、KH–602、封端剂及催化剂用量等对氨基硅油技术指标的影响,得到了完整的工艺配方.  相似文献   

5.
以二甲基硅氧烷混合环体(DMC)为原料,利用乳液聚合法制得聚硅氧烷乳液,并用乙醇醇解甲基三氯硅烷所得的甲基三乙氧基硅烷进行乳液交联,最后以三甲基氯硅烷作为封端剂为其封端.研究了交联温度、交联反应时间、交联剂用量以及封端剂用量对乳液的影响,并确定了最适宜的反应条件,即交联温度为(60±5)℃,交联时间4h左右,交联剂用量为DMC质量的34%~46%,封端剂用量为DMC质量的5%~7%.  相似文献   

6.
聚甲基丙烯酸丁酯具有优良的性能,在诸多领域展现出广阔的应用前景。本文以二甲基丙烯酸乙二醇酯(EGDMA)为交联剂,采用乳液聚合法制备了聚甲基丙烯酸丁酯纳米粒子,探索了交联剂EGDMA、引发剂过硫酸钾(KPS)和乳化剂十二烷基硫酸钠(SDS)等对纳米粒子的粒径、乳液固含量、单体转化率的影响规律。实验结果表明,EGDMA、KPS、SDS加入量分别为10%(单体摩尔分数)、0.4%(单体摩尔分数)和0.4%(质量分数)时,制备得到的乳液单体转化率达95%,乳液凝聚率低,得到的聚合物粒径达到45nm。  相似文献   

7.
通过半连续预乳化法,用八甲基环四硅氧烷(D4)和γ-甲基丙烯酰氧丙基三甲氧基硅烷(KH570)对苯丙聚合物乳液进行改性。探讨D4开环聚合催化剂十二烷基苯磺酸(DBSA)的加入方式和引发剂、KH570、D4及丙烯酸羟乙酯(HEA)的用量对乳液性能的影响。当催化剂DBSA全部加入到底料中时,有利于稳定乳液的制备。确定了制备稳定的有机硅改性丙烯酸酯乳液的最佳组分,对乳胶膜的力学性能和耐水性进行了表征。  相似文献   

8.
甲醇为起始剂,与萘钾反应转化为醇钾,以醇钾为引发剂依次引发环氧乙烷(EO)、环氧丙烷(PO)阴离子开环聚合,合成环氧乙烷-环氧丙烷(PEO-PPO)两嵌段共聚物,然后用甲基丙烯酰氯(MAC)为封端剂对该嵌段共聚物进行封端,得到可聚合型大分子乳化剂(PEO-PPO-MA),其中聚环氧乙烷部分为亲水链段,聚环氧丙烷部分为疏水链段。采用GPC1、H-NMR对PEO-PPO-MA的结构进行了表征,并用表面张力法测定了PEO-PPO-MA的临界胶束浓度(CMC)值。以合成的可聚合型大分子聚合物作为乳化剂直接进行苯乙烯的乳液聚合,研究了加料方式对乳液聚合的影响。结果表明,聚合所得乳液粒径均匀,且在加入乙醇、MgSO4及冻融条件下均具有很好的稳定性。  相似文献   

9.
速溶型聚丙烯酰胺的反相微乳液聚合   总被引:4,自引:0,他引:4  
采用过硫酸钾 -尿素为引发剂 ,span 6 0为乳化剂 ,进行了丙烯酰胺 (AM)的反相微乳液聚合 ,讨论了引发剂用量、单体浓度及聚合温度对于单体转化率的影响 同时在聚合体系中加入少量硫酸钠以提高聚合物的溶解速度 ,得到了比较满意的结果  相似文献   

10.
有机硅改性丙烯酸酯乳液聚合的乳化体系研究   总被引:1,自引:0,他引:1  
研究了三种单体投入方式对有机硅改性丙烯酸酯乳液聚合稳定性及性能的影响.单体转化率、凝胶率及粒径分析结果表明,采取半连续种子乳液聚合方法最有利于硅丙乳液聚合,单体转化率达97%,凝胶率小于0.6%,平均粒径为100nm,且分布较窄.在此基础上进一步研究了复合乳化剂的配比及用量对乳液性能的影响,实验结果表明m(阴离子)/m(非离子)/m(两性)复合乳化剂体系配比为2:1:1且用量为4%时能够获得综合性能较好的乳液,且反应性乳化剂DNS-86可以随其他种类乳化剂一起全部加入反应体系.红外分析及透射电镜观察进一步表明在该最佳乳化剂体系条件下通过单体滴加方式能够获得形态规整、大小基本一致的硅丙乳液.  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.
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   

13.
王慧 《科技信息》2008,(10):240-240
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   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
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   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
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   

20.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

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