首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 500 毫秒
1.
特种工程塑料聚芳醚酮的研究进展   总被引:8,自引:0,他引:8  
阐述了聚芳醚酮的基本性质、合成方法及新型结构聚芳醚酮的设计及研究进展,并指出了聚芳醚酮的应用前景。  相似文献   

2.
通过β-萘酚和4,4′-二氟二苯甲酮的缩合反应,合成了一种新芳醚单体-4,4′-二(β-萘氧基)二苯甲酮,将其在亲电反应条件下和二苯醚、芳二酰氯进行共缩聚反应,制备了聚醚酮酮/含萘环聚醚酮醚酮酮无规共聚物,用IR、WAXD、DS、TG和溶解性试验等方法对其进行了表征。  相似文献   

3.
以4.4’-二氟二苯酮,4,4’-二氯二苯砜和双酚S为单体,通过溶液缩聚法合成了聚芳醚酮砜共聚物系列样品,并用IR,DSC,TGA和动态粘弹谱仪进行表征.结果表明:共聚物是无定形聚合物,其热性能和动态力学性能介于聚醚酮醚砜和聚醚砜之间,共聚物的T_g随组成的变化符合Fox方程,酮类组分有利于提高共聚物的耐高温性能。  相似文献   

4.
用酸碱中和法和离子交换法由磺化聚醚酮酮制得了一价型聚醚酮酮磺酸盐和二价型聚醚酮酮磺酸盐。IR分析表明,两种方法制备的价数相同的聚醚酮酮磺酸盐有相似结构;TG分析表明,一价型聚醚酮酮磺酸盐的热分解发生在520℃;而二价型聚醚酮酮磺酸盐在370℃有一失去磺酸基的小热分解峰,520℃发生主链的热分解。  相似文献   

5.
合成了聚醚酮酮,并用广角X射线、红外及差示扫描丘热技术研究聚醚酮酮及其共聚体系。研究表明这种体系存在多晶型结构,第Ⅰ晶型与通常聚醚醚酮晶型相同;第Ⅱ晶型与第Ⅰ晶型不同。第Ⅱ晶型晶胞参数a=0.3997nm,b=0.5667nm,c=0.9861nm。改变共聚体系分子链结构及制样与热处理条件均可得到这两种晶型的变化情况。  相似文献   

6.
将氟端基聚醚醚酮酮齐聚物和羟端基聚醚砜齐聚物通过溶液缩聚,合成聚醚醚酮酮-聚醚砜有规嵌段共聚物,并用IR、DSC、TGA、WAXD等测试手段进行表征,结果表明:共聚物没有相分离,是组分相容体系。聚醚砜组分含量变化对共聚物的热性能和结晶行为影响很大,对聚醚醚酮酮改性效果明显。  相似文献   

7.
本文报导了聚醚酮酮醚酮(PEKKEK)的合成,并探讨了各种聚合条件对聚合反应的影响。由此提出较为合适的聚合工艺。在合成出高分子量 PEKKEK 的基础上,进一步对聚合体的结构和性能进行了表征。红外光谱(IR)分析结果确证了聚合体中羰基和醚健的存在,差热分析(DSC)结果则表明 PEKKEK 为典型的半结晶高聚物,其熔点(380.2℃)高于 PEEK(338℃)。热失量(TGA)的测定结果表明 PEKKEK 耐热性能突出,其热稳定性明显优于 PEEK。  相似文献   

8.
以无水AlCl3/ClCH2CH2Cl/NMP为催化剂/溶剂体系,通过亲电缩聚反应,由二苯醚(DPE),对苯二甲酰氯(TPC)和4,4′-二(α-萘氧基)二苯酮(DNBP)合成了一类新型主链含1,4-亚萘基结构的聚醚酮酮/聚醚酮醚酮酮(PEKK/PEKEKK)无规共聚物。研究了DNBP结构单元对共聚物性能的影响,并对其进行了IR、DSC、TG、WAXD等分析表征。结果表明,共聚物具有优良的耐热性和耐溶剂性,随着共聚物中DNBP结构单元含量的增加,其玻璃化温度(Tg)逐渐升高,而熔融温度(Tm)和结晶度逐渐降低,热分解温度(Td)均大于540℃。与PEKK相比,共聚物的断裂伸长率明显提高,拉伸强度和拉伸模量略有下降,但仍具有良好的力学性能。  相似文献   

9.
通过苯基取代的二氮杂萘酮的衍生物1a和1b与活性的含氟单体反应合成了两种新的苯基取代的含二氮杂萘酮结构的聚芳醚酮酮。聚合物3a和3b的结构由FT-IR与NMR进行表征,此类聚合物表现出很高的玻璃化转变温度和优良的热稳定性。  相似文献   

10.
间甲基二苯醚改性聚醚酮酮的研究(Ⅰ)   总被引:1,自引:1,他引:0  
以间甲基二苯醚对全对苯基位聚醚酮酮进行了改性研究。结果表明,随着Me-PEKK含量的增加,共聚物的对数比浓粘度,Tg,Tm和结晶逐渐下降,但仍具有很好的耐热性,其溶解性得到了明显的改善。  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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号