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1.
水性涂料用聚氨酯/丙烯酸酯复合乳液合成技术的研究   总被引:1,自引:0,他引:1  
大量研究表明,将聚氨酯和聚丙烯酸酯结合在一起得到的聚氨酯/丙烯酸酯复合乳液(PUA)可使涂膜获得更优异的性能,在水性涂料中有重要的应有价值.PUA复合乳液的合成方法对复合组分的相容性以及复合乳液乳胶膜的性能有重要的影响.本文综述了水性聚氨酯/丙烯酸酯复合乳液主要合成方法的研究状况,并对各种方法进行比较.  相似文献   

2.
以丙烯酸酯单体为原料,水性聚氨酯为种子乳液和高分子乳化荆,合成了核-壳结构的聚氨酯-丙烯酸酯复合乳液.采用傅里叶红外光谱表征了反应产物的结构.研究丙烯酸酯与聚氨酯质量比、丙烯酸酯软硬单体质量比对复合乳液性能、胶膜耐水性、热稳定性及180°剥离强度的影响.结果表明:随丙烯酸酯与聚氨酯质量比和丙烯酸酯硬单体质量的增加,复合乳液黏度减小,粒径增大,胶膜耐水性和热稳定性提高.当丙烯酸酯与聚氨酯质量比为2.0,丙烯酸酯软单体与硬单体质量比为75/25时,聚氨酯-丙烯酸酯复合乳液黏合荆对双向拉伸聚丙烯/铝箔的粘接强度优于国外样品.  相似文献   

3.
酮肼交联型聚氨酯-氟化聚丙烯酸酯乳液的制备   总被引:3,自引:0,他引:3  
采用单体预乳化的乳液聚合工艺,利用丙烯酸酯单体、有机氟单体、双丙酮丙烯酰胺合成含有活性酮羰基的氟化丙烯酸酯乳液;然后同合成的含有酰肼基的聚氨酯乳液按一定的比例混合制备出酮肼交联型聚氨酯-氟化聚丙烯酸酯(FPUA)复合乳液.通过红外光谱、激光粒径分析、透射电镜、接触角和耐溶剂性、耐水性能检测等方法对FPUA复合乳液及成膜物的组成和结构进行了分析和表征,并对复合乳液的涂料印花性能进行了检测.  相似文献   

4.
水性聚氨酯-丙烯酸酯复合乳液的合成与表征   总被引:1,自引:1,他引:0  
为开发高性能且环保的丙烯酸酯改性水性聚氨酯乳液,以甲苯二异氰酸酯、聚醚二元醇、二羟甲基丙酸(DMPA)和甲基丙烯酸甲酯为主要原料,采用原位乳液聚合法,先制得水性聚氨酯预聚物/乙烯基单体混合物,然后加入引发剂,经自由基乳液聚合得到聚氨酯一丙烯酸酯(PUA)复合乳液,并对影响复合乳液性能的因素进行了探讨.研究发现,PUA复合乳液的性能及外观与-NCO/-OH比(物质的量比,下同)、二羟甲基丙酸(DMPA)含量以及中和度等密切相关.当n(-NCO):n(-OH)=1.3~1.4,-COOH质量分数在2.6%左右.中和度为90%~100%时,所得PUA复合乳液的外观好、性能佳.  相似文献   

5.
以聚酯二元醇、甲苯二异氰酸酯、二羟甲基丙酸(DMPA)、水合肼等为原料,制得了自乳化的肼基封端聚氨酯稳定乳液。以苯乙烯、丙烯酸乙酯、丙烯酸异辛酯、丙烯酸和双丙酮丙烯酰胺为单体,通过乳液聚合制得了含酮羰基丙烯酸酯共聚物乳液。将含肼基和酮羰基的两种乳液共混,所得复合乳液用作塑 塑复合粘合剂,使其在室温下发生酮肼交联反应以提高粘接性能。考察了预聚反应时间对预聚反应程度、不同DMPA含量和R-值(预聚体中n(—NCO)/n(—OH))对聚氨酯乳液性能以及两种乳液配比对胶膜凝胶含量、吸水率及180°剥离强度的影响,并比较了含肼基聚氨酯和小分子己二酰肼对丙烯酸酯共聚物乳液的改性效果。结果表明:当预聚反应210min、DMPA质量分数4.5%、R值小于1.5时,可制得稳定的聚氨酯乳液;随着共混乳液中肼基含量的增加,乳胶膜凝胶含量增大,吸水率增加,180°剥离强度降低;含肼基的聚氨酯对丙烯酸酯共聚物乳液的改性效果优于小分子己二酰肼的改性。  相似文献   

6.
含氟单体对聚氨酯-氟化丙烯酸酯复合乳液性能的影响   总被引:3,自引:0,他引:3  
以甲基丙烯酸十二氟庚酯(DFMA)和丙烯酸酯为单体,以水性聚氨酯作种子乳液,通过单体滴加法和单体预乳化法两种不同的聚合工艺制备聚氨酯-氟化丙烯酸酯(FPUA)复合乳液.对FPUA胶膜的结构和性能进行了检测与表征,探讨了含氟单体、不同聚合工艺对FPUA复合乳液聚合稳定性及胶膜性能的影响.  相似文献   

7.
丙烯酸树脂交联改性水性聚氨酯乳液   总被引:8,自引:0,他引:8  
文中利用肼基与酮羰基之间的脱水缩和反应制备了丙烯酸树脂交联改性水性聚氨酯乳液。探讨了肼基、酰胺基的含量对水性聚氨酯(PU)乳液、苯丙(PA)乳液性能的影响以及交联反应对漆膜性能的影响。实验结果表明,水性聚氨酯中加入肼基化合物提高了膜的拉伸强度,硬度及耐水性等性能,同时发现,肼基化合物的用量在不超过4%时水性聚氨酯乳液最稳定;酰胺化合物的用量对苯丙乳液也有较大影响,酰胺化合物在乳液中质量分数小于6%时,丙烯酸乳液的稳定性最好。丙烯酸树脂交联改性水性聚氨酯乳液,其拉伸强度、硬度等皆比改性前的聚氨酯、丙烯酸乳液要好,当酰胺基化合物与肼基化合物保持相同交联基团摩尔比时,得到乳液性能最好。  相似文献   

8.
概述聚氨酯-聚丙烯酸酯复合乳液的制备方法。特别对聚氨酯-聚丙烯酸酯复合乳液共聚法作了较为系统的介绍和讨论。  相似文献   

9.
甲基丙烯酸甲酯与水性聚氨酯的共聚反应   总被引:19,自引:4,他引:15  
采用甲基丙烯酸甲酯(MMA)与水性聚氨酯乳液共聚制备聚氨酯-丙烯酸酯(PUA)复合乳液,研究了MMA添加量对PUA复合乳液的制备及涂膜性能的影响,并应用傅立叶红外光谱(FTIR)和凝胶渗透色谱测定反应产物的结构和相对分子质量.研究发现随MMA添加量增大,PUA复合乳液平均粒径增大,粘度减小,PUA树脂的相对分子质量增大,涂膜光泽度下降,机械性能变好,涂膜耐水、耐乙醇性增加.合适的MMA添加量为体系总固体质量的20%~30%.  相似文献   

10.
以二羟甲基丙酸(DMPA)、双丙酮丙烯酰胺(DAAM)为功能性单体,以丙烯酸酯类为溶剂合成了水性丙烯酸酯聚氨酯(PUA)复合乳液,成功的解决了以丙酮为溶剂制备水性聚氨酯造成的VOC含量高、工艺复杂、浪费能源的问题。通过红外(FT-IR)、透射电镜(TEM)等测试手段及吸水率、耐溶剂性、硬度、凝胶含量的测定,考察了丙烯酸酯聚氨酯复合乳液(PUA)及其涂膜的结构与性能,结果表明PUA复合乳液涂膜硬度达到3H,凝胶含量可达到84.3%,且耐水性、耐溶剂性得到明显提高。  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 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   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
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   

15.
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   

16.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
19.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

20.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

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