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1.
采用机械共混将氯化聚乙烯(CPE)与自制的吸水树脂丙烯酸-甲基丙烯酸-β羟乙酯共聚物[P(AA-HEMA)]共混,并讨论了吸水树脂以及增容剂对共混试样的力学性能的影响,研究表明简单共混时随吸水树脂量增大,共混试样的力学性能降低,CPE-g-HEMA的加入改善了试样的力学性能;但当其用量过饱和后,共混体系的反而力学性能下降,以加入3phr的CPE-g-HEMA的增容效果最为明显。  相似文献   

2.
通过熔融共混法制备了HDPE NBR共混物 ,采用毛细管流变仪研究其流变特性。结果表明 :此共混体系属于假塑性流体 ,表现粘度随剪切速率和温度的升高而降低 ,随NBR和增容剂含量的降低而降低。  相似文献   

3.
采用机械共混、化学交联工艺制备高聚合度聚氯乙烯(HMWPVC)/聚甲醛(POM)/丁腈橡胶(NBR)三元共混弹性体合金。重点讨论了HMWPVC/POM/NBR共混比、PVC树脂的相对分子质量、NBR橡胶的丙烯腈含量、硫化体系等因素对弹性体性能的影响。HMWPVC/POM/NBR共混弹性体的力学性能、耐油耐溶剂性能优于PVC/POM/NBR共混弹性体。采用动态粘弹谱仪、扫描电子显微镜等现代分析技术研究了HMWPVC/POM/NBR三元共混弹性体的微观结构,结果显示HMWPVC/POM/NBR(10/10/80)三元共混弹性体的tgδ-T谱上只出现一个峰值,其对应的玻璃化转变温度为-0.8℃,三元共混弹性体具有较好的相容性。  相似文献   

4.
聚氯乙烯/三元共聚尼龙共混物的形态结构   总被引:2,自引:0,他引:2  
采用乙烯-丙烯酸正丁酯-一氧化碳共聚物(EnABCO)及马来酸酐接枝乙烯-丙烯酸正丁酯-一氧化碳共聚物(EnABCO-g-MAH)两种增容剂对聚氯乙烯(PVC)/三元共聚尼龙(NT)共混物进行增容,得到了一类新型的PVC/NT共混物,用SEM,DMTA、DSC对共混物的形态结构,结晶情况进行了表征;对增容剂的增容机理和增容效果进行了探索与评价;结果表明:增容和未增容PVC/NT共混物都是典型的的两相体系;PVC/NT质量比在75/25~25/75的范围内NT均为连续相;共混物中EnABCO比EnABCO-g-MAH对PVC有更强的增塑作用,共混物有冷结晶现象,EnABCO增容共混物中的NT结晶能力比较弱。  相似文献   

5.
聚醚砜与聚碳酸酯增容共混物及性能   总被引:1,自引:1,他引:0  
以双酚-S-型聚芳酯为增容剂,对聚醚砜/聚碳酸酯(PES/PC)共混体系的形态结构及力学性能进行了研究,结果表明,双酚-S型聚芳酯可有效地增加两相间的界面黏结性,显著降低PES/PC共混物中PC分散区的尺寸,改善两组分间的相容性.SEM分析表明,增容剂的加入,使共混体系形成双连续相的互锁结构,这种结构有利于提高共混体系的力学性能.  相似文献   

6.
用小角X光散射(SAXS)对聚氯乙烯/线型低密度聚乙烯(PVC/LLDPE)共混体系的界面结构进行了研究,探讨了体系宏观性能与微观结构之间的关系。发现氢化聚丁二烯—b—甲基丙烯酸甲酯(HPBD—b—PMMA)共聚物是PVC/LLDPE共混体系有效的增容剂,其分子量在很大的范围内都提高了共混体系的力学性能,其增容本质是增加了相界面间的热力学相容性,而相间分子缠结对体系的宏观性能却影响不大。  相似文献   

7.
在制备高聚合度聚氯乙烯(HMWPVC)/聚甲醛(POM)/丁腈橡胶三元共混弹性体的工作基础上,进一步探讨了防老剂品种和用量,炭黑品种和用量,增塑剂品种、共混温度,共混时间,加料顺序等因素对三元混弹性体力学性能的影响,结果表明,1.0-1.5份防老剂MB对HMWPVC/POM/NBR三元共混弹性体的防护效果最好,加入15-60份半补强炭黑时,拉伸缩强度提高40%-56%,撕裂强度提高46%-89%,耐溶剂性能显著改善;HMWPVC/POM/NBR三元共混弹性体适宜的共混温度175-180℃,共混时间5-7min.  相似文献   

8.
聚苯乙烯和聚乙烯的三维混沌混合   总被引:1,自引:0,他引:1  
采用自制的三信混沌混合装置,研究了聚苯乙烯(PS)与少量低密度聚乙烯(LDPE)进行共混时,共混物中少相LDPE的结构演化及其对共混物韧性的影响,扫描电子显微镜(SEM)和透射电子显微镜(TEM)的分析表明,随着混合周期数的增加,少相经历了由宏观颗粒→层片→纤维→微观颗粒的演化过程,最终形成了高长径比的纤维和大量尺寸瓣颗粒,而增容剂聚苯乙烯-聚乙烯-丙烯(SEP)的加入,对这一结构的形式是有利的,冲击强度测试表明,在不加入增容剂时,LDPE对PS没有增韧作用,原因在于相间界面结合很差,当加入少量的增容剂后,可以垢增韧效果。  相似文献   

9.
通过对增容前后共混物的冲击断面形态、Molau实验现象、动态粘弹行为差异的研究和增容共混物抽提物的结构表征.探讨了共混体系的反应挤出增容机理.FT-IR分析表明抽提残余物中含有PC-g-HDPE接枝物。增容共混物的Tg、Tmax向低温方向偏移3-4℃,证实了熔融共混过程中增容剂HDPE-g-GMA的环氧基团与PC的酚羟基发生。原位”化学反应.并生成PC-g-HDPE接枝物;该接枝物分布于两相界面,起到提高界面粘结力、促进UHMWPE分散等作用。产生了良好的增容效果.属反应性增容作用机理.  相似文献   

10.
研究了PP-g-GMA对PP/PA6(羧端基尼龙)共混物的反应增容作用及其对共混物力学性能的影响,考察了反应增容与非反应增容的优劣.研究结果表明,PP-g-GMA对PP/PA6共混物具有显著的反应增容作用,并且增容效果优于PP-g-MAH的非反应增容效果;PP-g-GMA的反应增容对共混物力学性能的影响远大于PP-g-MAH的非反应增容对共混物力学性能的影响.  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.
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   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
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   

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.
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   

18.
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   

19.
20.
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   

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