首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   51篇
  免费   0篇
  国内免费   1篇
化学   9篇
综合类   43篇
  2009年   3篇
  2008年   6篇
  2007年   1篇
  2006年   2篇
  2005年   2篇
  2004年   3篇
  2003年   2篇
  2002年   5篇
  2001年   5篇
  2000年   12篇
  1999年   2篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1993年   2篇
  1991年   1篇
  1988年   1篇
  1984年   1篇
  1980年   1篇
排序方式: 共有52条查询结果,搜索用时 15 毫秒
31.
离子化共聚酯的热转变及结构形态研究   总被引:4,自引:0,他引:4  
本文以差示扫描量热法(DSC)连续升温和降温,对含量不同的离子化共聚酯(聚合物)由对苯二甲酸PTA、乙二醇EG、间苯二甲酸磺酸钠Na-SIPA缩聚制备,产物中含有(10mol%的离子基团)进行大范围温度扫描,表征了离子化共聚酯分子运动以及热性能的各种特征。在SIP含量≥3mol%时发现在熔融过程中存在热可逆变化,而且随着SIP含量的增加该变化更加明显,并随样品热处理条件的不同而呈现出不确定性,表明了离子基团之间存在着强烈的相互作用,而且这种作用以多种形式存在并由此形成了聚集形态的多样性。运用离子聚集理论分析了实验结果,为离子聚集理论提供了新的实验依据。  相似文献   
32.
IntroductionTheuseofsoybean ,peanut,zeinandothervegetableproteinsasinexpensivefibermaterialstoreplacewoolandsilkcanbetracedbackto 1930s.Earlyin 1935 ,theItalianfirm ,SniaViscosa ,beganlarge scaleproductionofcaseinfibers[1] .Shortlyafterward ,ICIinEngland produced peanut proteinfibersknownasArdil.CoCornProductRefiningmanufacturedzeinproteinfiberin 1939.Theseusesofseedmealsintoindustryenhancethevalueoftheagriculturematerial.Thelargeintroductionofpetroleum basedfibersduring 194 0sand 195 0s…  相似文献   
33.
纳米ATO改性聚丙烯腈纤维的研究   总被引:6,自引:0,他引:6  
采用高导电率的纳米粉体ATO(SnO2·Sb2O3)为抗静电剂,从6种不同类型的分散剂中筛选出聚乙烯亚胺,通过设计正交实验探索出最佳工艺组合,将纳米ATO稳定均匀地分散于去离子水中,将该悬浮液作为聚丙烯腈纤维纺丝过程的预热浴,来改善聚丙烯腈纤维的抗静电性,研究了ATO用量、添加位置等对纤维抗静电性能、力学性能的影响。  相似文献   
34.
Cellulose pulps were directly dissolved in a green solvent of sodium hydrate/urea/thiourea/water with different composition for the purpose to prepare new regenerated cellulose fibers or films. The results showed that the highest solubility of cellulose in the solvent with the composition of 8/8/6.5/77.5. The results revealed that the pulp feeding sequence, stirring rate, pre-treatment of pulp and pulp size affected the cellulose concentration in the green solvent. Accordingly, the more effective dissolution method was proposed in order to get higher concentration of cellulose. Furthermore, the properties of solution prepared by different kinds of pulps in the solvent were investigated by ARES rheometer. Rheologieal analyses indicated that all cellulose aqueous solutions in their high concentration were pseudoplastic fluids and sensitive to temperature and tended to transform to gel when temperature increased.  相似文献   
35.
Acetalizatioin on the blend fibers of poly (vinyl alcohol) (PVA) and soybean protein (SP) was studied by using dialdehydes as cross-linking agents. The optimal acetalization conditions were determined by Latin square experiment, where the modified fibers with good mechanical properties can be achieved by treating in 41 g/L dialdehyde solution at 67 ℃ for 9 min. The cross-linking reactions of PVA and SP with dialdehydes were confirmed by Fourier transform infrared (FTIR) spectroscopy. Tensile test and boiling water shrinkage measurements showed that the physical properties of PVA/SP fibers crosslinked by dialdehydes were improved comparing with those formalized fibers.  相似文献   
36.
嵌段共聚酯的合成研究   总被引:2,自引:0,他引:2  
采用直接酯化法合成了一系列含间苯二甲酸的PEIT-PEG嵌段共聚酯,研究了聚合时间,聚合效率及聚酯的特性粘度与产物中间苯二甲酸含量及共聚酯分子量的关系,得出适于纺丝工艺及工业化生产的共聚酯分子量和间苯二甲酸的含量。  相似文献   
37.
Crystallization behavior of poly(ethylene terephthalate-co-ethylene isophthalate)(PEIT) with different isoph-thalate contents (4%, 8% and 12%, designated asPEIT4,PEIT8 and PEIT12 respectively) has been inves-tigated by DSC and density measurement methods. Theresults show that the crystailinity of PEIT decreases withincreasing isophthalate content. However the crystallinity of PEIT8 is much smaller than that of PEIT12 whencooling from melt at a constant rate.The crystailinity ofPEIT8 cold-drawn filament shows almost the same val-  相似文献   
38.
The shrinkage behavior of copoiyester fibers (PEIT) and the ' latent - crimp behavior of side - by - side PET/ PEIT composite fibers have been studied. It is shown that the shrinkage rate, the crimp ratio and the crimp rigidity of these fibers increase with the increasing isoph-thalate content of PEIT and the treatment temperature. The shrinkage in boiling water of the cold - drawn PEIT - A2 fiber appears to be higher than that of PEIT - A3. The shrinkage in dry air of the cold - drawn PEIT - A2 fiber is also higher than that of PEIT at temperature of 393 K or 413K, but lower at 453K. The crimp rigidity of the PET/PEIT - A: conjugate fiber appears to be obviously higher than that of the PET/PEIT - A, conjugate fiber. The mechanism of the shrinkage behavior related these fibers are discussed in detail.  相似文献   
39.
借助由X射线衍射法,密度法,DSC法测定的结晶度和沸水收缩率,自然拉伸比,声速取向因子等指标来描述纺丝速度在2400-5000m/min范围内变化的PEIT卷绕丝的超分子结构。在实验的纺速范围内,PEIT卷绕丝的结晶度随纺速增加的过程中有突变现象,这主要是因为分子取向诱导所致。最后,就不同纺速下PEIT初生丝的力学性能特征值进行了对比。  相似文献   
40.
使用氢氧化钠/硫脲/尿素/水溶液作为纤维素的复合溶剂,研究了纤维素在其中的溶解行为和溶液性质,发现该体系在-10℃条件下能快速溶解纤维素,其溶解是一个没有衍生物生成的直接过程,该纤维素溶液在过高温度下易凝胶化.  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