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1.
以氯丁橡胶为主原料,添加增粘树脂改性,采用沥青和混合溶剂制成钢窗密封胶粘剂Ⅰ号。此胶粘剂与同类型丹麦进口的S—90胶粘剂多数性能相当,有些性能还较优越,完全可以代替进口密封胶的使用。  相似文献   

2.
烟火剂型底排药成分分析用甲苯-乙酸乙酯混合溶剂溶解氯丁橡胶、松脂酸钙和六次甲基四胺,通过蒸馏水萃取除去六次甲基四胺组分,盛装于烧杯中蒸干的氯丁橡胶、松脂酸钙再用乙酸乙酯溶解松脂酸钙转移分离,从而实现氯丁橡胶和松脂酸钙定量分离检测研究。产品检测应用表明,甲苯一乙酸乙酯混合溶剂对单质氯丁橡胶、松脂酸钙、六次甲基四胺回收率在98%以上。试验研究和实际产品检验中,氯丁橡胶、松脂酸钙硷测误差均在±1.5%内(相对误差小于10%).该方法也可应用于类似混合炸药的成分分析。  相似文献   

3.
胶粘剂化学   总被引:1,自引:0,他引:1  
本文简介了无机胶粘剂、环氧树脂胶粘剂、酚醛树脂胶粘剂、丙烯酸系胶粘剂、不饱和聚酯胶粘剂、聚氨酯胶粘剂、耐高温胶粘剂等的组成和化学原理,说明了胶粘剂在国民经济中的重要作用和粘合连接的优越性。  相似文献   

4.
木质素活化及在木材胶粘剂中的应用进展   总被引:7,自引:0,他引:7  
木质素是相对分子量较高的天然聚合物,由于具有苯酚结构利于制备木材胶粘剂,但是木质素本身反应活性低,一般都将其活化后再利用.而且,除了以往利用最多的造纸工业产生的木质素外,研究发现木材经过褐腐菌降解后残留主要成分是结构部分发生变化的木质素,这种可再生生物质资源以其自身的结构特点在合成胶粘剂上也有很大的优势,本文结合木质素胶粘剂应用中的问题,重点概述了活化木质素的各种方法及褐腐木质素在木材胶粘剂中的应用.  相似文献   

5.
丙烯酸酯共聚物改性聚氨酯胶粘剂性能的研究   总被引:3,自引:0,他引:3  
以2402酚醛树脂/聚氨酯为胶粘剂组分,得到具有优秀粘接强度的胶粘剂体系。通过自由基无规共聚合的方法合成出一系列不同玻璃化温度(-40~80℃)的聚丙烯酸酯,并对胶粘剂进行改性。结果表明:2402酚醛树脂的适量加入不仅可以改善胶粘剂对被粘面的浸润性、调节胶粘剂的粘度,还可以提高胶粘剂的粘接性能;使T剥离强度达到45N/cm;而丙烯酸酯共聚物的加入虽然降低了胶粘剂的粘接性能,使T剥离强度降至20~30N/cm,却可拓宽胶粘剂的阻尼温域,达到50℃。用SEM研究了不同组分对胶粘剂微观形貌的影响,用DMA研究了聚丙烯酸酯的改性对胶粘剂的阻尼性能的影响。  相似文献   

6.
热熔压敏胶粘剂   总被引:1,自引:0,他引:1  
赵升 《化学教育》2007,28(6):11-12,16
介绍了新一代压敏胶粘剂——热熔压敏胶粘剂(HMPSA)的发展概况,重点阐述了聚丙烯酸酯压敏胶粘剂的类别、合成及应用等,并展望了HMPSA在社会生活中良好的市场前景。  相似文献   

7.
利用X射线能谱分析 (EDX)计算出粘接层胶粘剂水分含量的增加 ,从而计算出胶粘剂粘接碳 碳复合材料湿热老化后的扩散系数和扩散动力学 ,该方法不用将仅 0 1mm厚的胶粘剂从被粘材料表面除去再进行分析 ,因此相对简单 ,与元素分析测试方法相比误差较小 .比较了碳 碳复合材料表面不同处理方法粘接接头的水分扩散系数和扩散动力学 ,表明碳 碳复合材料经偶联剂处理的耐久性能要好于化学氧化和砂纸打磨处理 .  相似文献   

8.
海洋贻贝因其分泌的含邻苯二酚结构的多巴粘附蛋白而拥有在潮湿或者水下环境对不同固体表面快速而牢固的粘附能力.通过模仿贻贝中大量丰富的多巴粘附蛋白结构的仿生胶粘剂能在干燥和水下环境中实现对各种基材的有效粘接.最近十余年来,学术界一直致力于合成含邻苯二酚结构的仿生聚合物胶粘剂,探究聚合物本体和外界环境对胶粘剂粘接性能的影响....  相似文献   

9.
高分子材料类专业胶粘剂课程教学探析   总被引:1,自引:0,他引:1  
从我国胶粘剂产业的快速发展对专业技术人才的需求出发,提出了在高等学校的高分子材料类专业中开设胶粘剂课程的重要性,介绍了胶粘剂课程具有多学科高度交叉并集理论性、实践性和应用性于一体的教学特点,并结合近几年胶粘剂行业发展的新情况和我们在胶粘剂课程中的教学经验,总结了在讲授过程中的教学体会和教学方法,认为通过抓住课程特点和明确主线、灵活运用多媒体教学手段、增加实践性教学环节以及注重教学效果反馈等手段和措施,可以有效提高该类课程的教学质量。  相似文献   

10.
反应性高分子科技文摘由环氧聚氯丁橡胶制备离子交换剂Durgaryan,A.A.;etal,SU1,680,722(1991)在C6H6-DMF混合物中,通过环氧聚氯丁橡胶(环氧度90mol%)和Na2S反应,制得了一种提高了对Hg3+的吸附容量的离子...  相似文献   

11.
Poly(hexafluoropropylene oxide), poly(HFPO), networks were prepared from functional polymers by end linking via urethane groups. The prepolymers were characterized by NMR spectroscopy and GPC. The networks were characterized by determination of the number of network chains from the shear modulus, and were snown to contain both trifunctional crosslinks and difunctional links. The properties of the networks were investigated by a range of techniques. Compared with fully-fluorinated networks formed via triazine cross-links, investigated previously, the urethane-linked networks were more readily prepared but were poorer elastomers, were less thermally stable, and were less resistant to swelling by common polar solvents. © 1995 John Wiley & Sons, Inc.  相似文献   

12.
对烘烤前后南瓜籽中的化学成分进行分析并对比。采用同时蒸馏萃取装置萃取南瓜籽中的挥发性成分,采取超临界CO2萃取技术萃取南瓜籽油脂,并将其分为酸、碱、中性三个部分,用气相色谱-质谱联用方法分析其中化学成分并进行对比。结果表明,南瓜籽挥发性成分中含有多种醛类和酯类化合物,烘烤后产生了大量的烷基吡嗪,其在碱性部分中的相对含量比烘烤前提高14倍多,不饱和醛类化合物含量也有明显提高。南瓜籽油脂中的主要化学成分是油酸、亚油酸及其酯类。还含有生物活性功能成分如植物甾醇、角鲨烯和维生素E等。烘烤后除角鲨烯含量有所降低,维生素E、植物甾醇、亚麻酸等均有提高。  相似文献   

13.
采用溶胶-凝胶法制备了多孔氧化铝膜, 并通过DSC、TGA、SEM、N~2吸附和气体透过率测定等手段, 对膜的性能进行了表征。结果表明, 用这种方法制备的多孔氧化铝膜是一种均匀无裂痕和具有较窄孔径分布(约4nm)的膜材料。将此多孔氧化铝膜制成膜反应器后, 用于甲醇催化脱氢制甲醛的反应, 发现甲醇转化率比常规反应器有较大幅度的提高。同时首次尝试采用溶胶-凝胶法将催化活性组分直接负载到多孔氧化铝膜上, 从而得到了一种具有催化活性的多孔膜, 并考察了它的反应活性。文中对由这两种多孔膜及钯/陶瓷复合膜制成的反应器的特点进行了比较。  相似文献   

14.
蔡孟深  曹小冬 《化学学报》1988,46(9):887-894
本文报道了一些取代苯酚的合成, 并探讨了用Grignard试剂合成取代苯酚中酚羟基的保护及脱保护的问题. 利用苄基和甲基作为酚羟基的保护基, 对文献报道的切断醚键脱保护方法进行了评价. 找到了两种新体系能在更温和条件下切断醚键的方法, 指出了它们的适用条件. 实验结果符合硬软酸碱理论.  相似文献   

15.
幼儿身高、体重和头发、血液锌铅含量关系的研究   总被引:4,自引:0,他引:4  
同步检测了151例3-4岁健康幼儿的身高、体重以及头和全血中的锌、铅含量。研究了身高、体重和锌、铅含量的关系,指出无论是发锌或血锌含量与身高、体重多数呈正相关,但发铅与身高、体重主要呈负相关,血铅与身高、体重的关系较为复杂,多为非线性的二次函数关系。  相似文献   

16.
FT-IR and FT-Raman spectra of the biomolecule 5-aminouracil were recorded in the regions 400–4000 cm−1 and 10–3500 cm−1, respectively. The observed vibrational wavenumbers were analyzed and assigned to different normal modes of vibration of the molecule. Density functional calculations were performed to support wavenumber assignments of the observed bands. A comparison with the molecule of uracil was made, and specific scale factors were employed in the predicted wavenumbers of 5-aminouracil. With the purpose of study the important molecule 5-aminouracil, its equilibrium geometry and harmonic wavenumbers were calculated for the first time by the B3LYP DFT method. The vibrational wavenumbers were compared with IR and Raman experimental data. Also good reproduction of the experimental wavenumbers is obtained and the % error is very small. All the tautomeric forms of 5-aminouracil were determined and optimized. The dimer forms were also simulated. The energy, atomic charges and dipole moments were discussed and several general conclusions were underlined.  相似文献   

17.
探讨了不同预处理方法对国产玻纤滤筒本底值的降低效果,便于废气样品的分析测定。分别对空白滤筒、热硝酸、硝酸+硫酸和硝酸+EDTA、HCl处理后的滤筒进行分析,测得滤筒中金属元素的含量;对处理效果较好的一批滤筒进行空白加标,考察加标回收率,全程用电感耦合等离子体质谱(ICPMS)法对样品进行测定,结果发现空白滤筒中部分金属元素含量较高;热硝酸处理后,滤筒本底中铅含量有所降低,但其它元素去除效果不显著;硝酸+硫酸处理后,滤筒中铅含量剧增;硝酸+EDTA处理滤筒,铅可以得到较好的去除效果,大部分金属元素含量有了明显降低;基于HCl对金属有较好的溶出效果,浸泡可较好地降低滤筒中金属元素的含量,但大量氯离子存在对ICP-MS法测定的干扰较大。对硝酸+EDTA处理后的滤筒进行空白加标,大部分金属元素加标回收率75%。故以硝酸+EDTA处理玻纤滤筒可以使国产玻纤滤筒适用于废气样品的分析。  相似文献   

18.
《Analytical letters》2012,45(9):1511-1523
Anion and cation exchange high-performance liquid chromatography (HPLC) combined with inductively coupled plasma-mass spectrometry (ICP-MS) were used for speciation of selenium in supplements. All the parameters in the extraction, separation, and determination procedures were optimized. Recovery studies for the selenium species from the anion and cation exchange columns were performed and there were no analyte losses. Limits of detection for selenium(IV), selenium(VI), Se in selenomethionine, and Se in selenocystine were 0.85, 0.68, 0.84, and 0.99 nanogram per milliliter, respectively. Six brands were analyzed to identify and quantify the selenium species present, and the results found were compared with the values given on the labels. The selenium species matched the labeled species for four brands, whereas two brands were found to contain inorganic Se(VI) in contrast with the labeled claim of selenomethionine.  相似文献   

19.
云南菊科中草药中铅含量特征分析   总被引:3,自引:2,他引:1  
论述了云南27种菊科中草药及其水提取物中铅含量的特征。菊科植物及水提物中铅含量的频数分布为正偏态,两者的相关系数r=0.09,未呈现显著的线性相关。提取率较高的山紫苑、佩兰、木香铅实际含量低;铅含量高的叶下花、狭叶兔耳风、臭灵丹提取率又较低,减少了人体对Pb的过量摄入。  相似文献   

20.
The volatile flavour compounds of two commercial Irish beef meats (labelled as conventional and organic) were evaluated by gas chromatography-olfactometry and were identified by gas chromatography-mass spectrometry. The volatile compounds were isolated in a model mouth system. Gas chromatography-olfactometry was performed by a group of eight assessors using the detection frequency methodology. The odours of the detected compounds were described as well. Eighty-one volatile compounds were identified, 11 compounds of which possessed odour activity in the first beef sample and 14 of which in the second meat sample. Ten volatile flavour compounds were common to both: methanethiol, dimethyl sulphide, 2-butanone, ethyl acetate, 2- and 3-methylbutanal, an unknown compound, 2-octanone, decanal and benzothiazole. Two unknown compounds were only detected in the first sample while 2,3-pentanedione, 4-methyl-3-penten-2-one, 2-heptanone, dimethyl trisulphide and nonanal were only perceived in the second beef. Significant differences in terms of detection frequency, odour characteristics and in nature of the volatile flavour compounds were emphasised between the two samples.  相似文献   

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