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1.
选用苯乙烯(St)、丙烯酸丁酯(BA)和少量的反应性阳离子共聚单体N,N-二甲基,N-丁基,N-(3-甲基丙烯酰胺基)丙基溴化铵(DBMPA),以阳离子自由基型引发剂引发进行无皂乳液聚合,合成了稳定的无皂阳离子共聚物St/BA/DBMPA乳液。研究结果表明:增大阳离子单体浓度、引发剂浓度和主单体St/BA体积比,共聚物乳胶粒粒径减小,粒子数目增大;增大离子强度,粒径呈现一个增大-减小-增大的变化过程;粒子的表面电荷密度也由以上4个因素决定。所合成的乳液表面张力小,耐电解质和耐有机溶剂性能好,说明该乳液具有很高的化学稳定性。胶膜经高温处理后,耐水性大大提高。  相似文献   

2.
在无皂条件下,利用偶氮二异丁基脒盐酸盐(AIBA)作引发剂,探讨苯乙烯/丙烯酸丁酯/(二甲基丁基)甲基丙烯酰氧乙基溴化铵(St/BA/DMBMEAB)三元阳离子共聚物乳液制备的合理条件,通过电镜观察到粒子形态规则、大小均一.功能性单体DMBMEAB是以甲基丙烯酸二甲胺基乙酯和正溴丁烷为原料,选择乙腈作溶剂合成的,制取的最终产品纯度高、收率高  相似文献   

3.
研究了苯乙烯(St)在大分子单体(MM)的存在下于醇水体系中的分散聚合,反应是以马来酸酐引入双键的聚醚多元醇大分子单体为共聚反应型稳定剂,以AIBN为引发剂,十二烷基硫醇为链调节剂的条件下进行。研究了St初始浓度,引发AIBN用量及大分子单体用量对聚合物粒子的粒径和粒径分布的影响,得到了粒径为2.00~2.40μm接近于单分散的聚苯乙烯微球。  相似文献   

4.
在无皂条件下,利用偶二异丁基脒盐酸盐作引发剂,探讨苯乙烯/丙烯酸丁酯甲基丙烯酰氧乙基溴化铵三元阳离子共聚物乳液制备的合理条件,通过电观察到粒子形态规则,大小的均一,功能性单体DMBMEAB是以甲基丙烯酸二甲胺基乙酯和正溴丁烷为原料,选择乙作溶剂合成的制取的最终产品纯度高,收率高。  相似文献   

5.
LIPN聚氨酯/聚丙烯酸酯引发体系的研究   总被引:4,自引:0,他引:4  
探讨了各种引发体系对LIPN聚氨酯(PU)/聚丙烯酸酯(PA)合成过程的稳定性、粒子形态及单体转化率的影响。实验表明采用油溶性引发剂AIBN可得到粒子均一,稳定性好且单体残留量很少的乳液;其粒子形态为“翻转”型核壳结构  相似文献   

6.
研究了苯乙烯、丙烯酸丁酯和羧基单体(甲基丙烯酸和衣康酸)无皂乳液聚合,考察了引发剂(K2S2O8)浓度、电解质(NaCl)浓度和甲基丙烯酸与衣康酸配比改变对乳胶粒径和表面羧基含量的影响。实验结果表明:引发剂浓度是影响粒径大小的重要因素;当n(甲基丙烯酸):n(衣康酸)=1:1时,乳胶粒表面羧基含量最高。采用无皂乳液聚合,可制得表面羧基含量高、粒径较大且具有单分散的St-BA-MAA-IA乳液。  相似文献   

7.
首次用难溶于水的ABNI为引发剂,合成了特性粘数[η]为9.5dl/g的聚(2-甲基丙烯酰氧乙基)三甲基氯化铵(PDMC).研究了单体纯度,单体浓度、聚合温度、引发剂用量对聚合物分子量的影响.并对PDMC进行了IR、1HNMR、DSC分析,其中IR、DSC图谱还未见报道  相似文献   

8.
研究了阳离子表面活性剂CTAB在临界胶束浓度(CMC) 前对1 - 芘丁酸(PBA) 和1 - 萘乙酸(NAA) 荧光光谱的影响, 观测到PBA和NAA激基缔合物的发光. 实验证明: CMC前CTAB 能够诱导PBA, NAA激基缔合物的形成. 这一结果为设计阴离子表面活性剂的荧光检测新方法提供了理论基础.  相似文献   

9.
采用无皂乳液聚合方法,考察了单体比例及其用量、引发剂质量分数和溶剂丙酮的加入对丙烯酰胺(AAm)-苯乙烯(St)共聚物乳胶粒的形态与表面电荷性质以及乳液稳定性的影响.实验结果表明,加大聚合体系中单体的质量分数,可以得到粒径较大的乳胶粒,但乳液的表面电荷密度和机械稳定性减小.通过增大AAm在单体中的质量分数,增加引发剂的用量,或者往溶剂反应体系中添加部分丙酮,可得到粒径和表面电荷密度较小的乳液.  相似文献   

10.
偶氮二异丁腈引发甲基丙烯酸甲酯微乳液聚合   总被引:9,自引:1,他引:8  
以一种新的Y型乳化剂12-丁酰氧基-9-十八烯酸(BOA),制备了甲基丙烯酸甲酯(MMA)含量高达20%的微乳液,并以油溶性引发剂偶氧二异丁腈(AIBN)引发其聚合。实验表明,与单体含量较低的微乳液聚合相比,MMA在其含量较高的微乳液中聚合时表现出一些明显不同的特征,如在聚合初期,聚合主要在大粒子内进行。MMA的 聚合与非极性单体的微乳液聚合相比也比较特殊,其聚合速度和聚合物分子量与引发剂浓度、单  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.
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   

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