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1.
A new type of thermal stabilizer, antimony pent (isooctyl thioglycollate) (Sb(SCH2 COOC8 H17 )5), was synthesized by using antimony trioxide, isooctanol and thioglycolic acid in 2 steps. Firstly, antimony trioxide was oxidized into colloidal antimony peroxide. Then antimony peroxide and isooctyl thioglycollate reacted stoichiometrically for 2 h with the yield of 87%. This compound was used as thermal stabilizer for polyvinyl chloride(PVC).The results show that the thermal stability time is 52 rain at 200℃ by heat-ageing oven test when adding 2. 5% thermal stabilizer to PVC resin. Compared with antimony tris(isooctyl thiolycollate), the initial thermal stability of antimony pent(isooctyl thioglycollate) is better than that of antimony tris(isooctyl thioglycollate), while the longterm thermal stability time is shorter than that of antimony tris(isooctyl thioglycollate). Meanwhile, the synergism of antimony pent(isooctyl thioglycollate) with calcium stearate was studied, indicating that when the mass ratio of antimony pent(isooctyl thioglycollate) to calcium stearate is 2:1, the thermal stability time of PVC is 58 min.  相似文献   

2.
A unit cell of EDLC works on the principle of double-layer capacitance at the elec- trode/electrolyte interface where electric charges are accumulated on the electrode sur- faces and ions of opposite charge are arranged in the electrolyte side. EDLC is character- ized by its high capacitance, small leaking current, simple charge-discharge, high power output and long cycle life, etc. The capacitance of EDLC is about 20―200 times of tra- ditional capacitor and applicable in a wide temperatu…  相似文献   

3.
Nanometer Ni0.5Zn0.5Fe2O4 powders with spinel phase were prepared by the hydrothermal method using purified FeSO4 solution from sodium jarosite's slag as materials. The results show that the spinel phase of Ni0.5Zn0.5Fe2O4 powders begins to form at a relatively low temperature (130 ℃) and a shorter holding time (1 h) when pH=8. The crystallization kinetics equation at 200℃ is ln[-ln(1-x)] =-0.78+0.951n t. The growth activation energy of Ni0.5Zn0.5Fe2O4 grains is 41.6 kJ/moL in hydrothermal synthesis process. With the increase of sintering temperature, the density and diameter shrinkage of ferrite circulus increase, whereas its pores decrease. The results of magnetic measurements show that saturation magnetic flux density Bs increases and the coercivity Hc decreases with the increase of their sintering temperature. Magnetic parameters of all the investigated samples satisfy the character demand of high Bs, low Br and low Hc of soft magnetic ferrite materials.  相似文献   

4.
As for the coal seam with high stress, high gas and low permeability, a single technology cannot prevent the complex dynamic disasters. Because of this, the study proposes a new method of pressure-relief and permeability-increase technology of the high liquid–solid coupling blast. Through coal seam injection and charging structure change, the paper fully works out the dual functions of the water and explosion. Using the theoretical calculation, numerical simulation and physical experiments, we obtained that the initial blasting stress, displacement and overpressure of the liquid–solid coupling blast are much better than that of ordinary blasting. The technology has been used in the relative coal mine, and the application results show that the technique has effectively prevented the coal and gas outburst, which has a wide range of application.  相似文献   

5.
本文采用原位乳液聚合方法制备了聚丙烯酸丁酯一有机蒙脱土/聚(甲基丙烯酸甲酯-衣康酸)(PBA—OMMT/P(MMA-1TA)纳米复合材料。利用X-射线衍射仪(XRD)、差示扫描量热仪(DSC)、傅立叶变换红外光谱(FT-IR)和热重分析(TGA)对复合材料进行了表征。结果表明:单体已插层进人有机蒙脱土层间发生聚合反应,使有机蒙脱土片层间距由原来的0.59nm增加到0.88nm以上,且有机蒙脱土的加入能够显著提高纳米复合材料的玻璃化转变温度(Tg)和热稳定性能。  相似文献   

6.
0 INTRODUCTIONThedesignofoptimalWienerHopfcontrollerisamethodinthefrequencydomain,whichestablishesaquadraticcostfunctionacco...  相似文献   

7.
Poly ( l- lactide- co-glycolide ) ( PLGA ) with different compositions was prepared using stannous octaoate as catalyst by bulk ring-opening copolymerization of l-lactide and glycolide. The structure and properties of the PLGA copolymers were cbaracterized by means of attenuated total reflectance-Fourier transform infrared (ATR-FTIR), ^1H NMR, differential scanning calorimeter ( DSC and X-ray diffraction (XRD) methods, The experimented results indicate that the synthetic conditions and the composition of copolymers have art obvious influence on the structure of PLGA copolymers, The degradation rate of eopolymers increased with the increasing of the glycolide component in the copolymers.  相似文献   

8.
9.
A small molecular organic depressor glycerine-xanthate was synthesized. The effect of glycerine-xanthate on the flotation of sulfide minerals was investigated based on a function of pH value and concentration of glycerine-xanthate through flotation experiments in the presence and absence of Cu^2+. The results show that glycerinee-xanthate has a strong dressing effect on marmatite at pH〉6 and on arsenopyrite in weak acid and base conditions with butyl-xanthate as collector. In the presence of glycerine -xanthate, marmatite is activated by addition of Cu^2+, but arsenopyrite cannot be activated and remains unfloatable. So the selective separation can be achieved for two minerals. The depression of glycerine-xanthate on sulfide minerals was discussed based on the radical electronegative calculation and the theory of HSAB. Infrared spectrum shows that there are some -OH and-CSS-in glycedne-xanthate molecule, which competes with butyl-xanthate on the mineral surface. As a result of many hydrophilic groups in glycerine-xanthate, the surfaces of marmatite and arsenopyrite become hydrophilic, thus the flotation of marmatite and arsenopyrite is depressed. The collector is adsorbed preferentially on the surface of marmatite and it shows a better floatability in the presence of Cu^2+, whereas, the surface of arsenopyrite absorbs glycerine-xanthate and the flotation of arsenopyrite is depressed by glycerine-xanthate.  相似文献   

10.
PS-PAMAM-IDA chelating resins were prepared by low-generations of polyamidoamine(PAMAM) and then chloroacetic acid functionalizing commercially available ammoniated polystyrene matrix, to preconcentrate Ni2+ from synthetic aqueous samples. Different generations of PAMAM were used to obtain different chelating resins, PS-IDA, PS-1.0G PAMAM-IDA and PS-2.0G PAMAM-IDA. The synthesized resins were characterized by FTIR and elemental analysis. The effect of solution pH, kinetic studies, resin loading capacity, matrix effects etc., on metal ion adsorption to adsorbent phase, were studied by batch method. The PS-1.0G PAMAM-IDA resin was the most excellent adsorbents, with a maximum adsorption capacity of(24.09±1.79) mg/g for Ni2+ ion at pH=7. The interpretation of the equilibrium data was given by Langmuir isotherms model, and the correlation coefficient values for PS-IDA, PS-1.0G PAMAM-IDA and PS-2.0G PAMAM-IDA resins were 0.992, 0.994 and 0.987, respectively.  相似文献   

11.
有机硅-丙烯酸甲酯的乳液聚合研究   总被引:2,自引:0,他引:2  
用丙烯酰端基的环氧乙烷-环氧丙烷共聚物作为共聚单体及反应性乳化剂,研究了甲基丙烯酰丙基硅氧烷和丙烯酸甲酯的乳液共聚合。探讨了反应性乳化剂用量与单体转化率、反应时间和乳胶粒径的关系,研制了有机硅单体质量分数为40%的稳定乳液。此外,用1H-NMR研究了滴加乳化单体液滴和一次加料两种方法下,共聚物组成与单体转化率的关系。结果表明,加料方式对共聚物组成有较大影响,水溶性大的单体优先聚合。  相似文献   

12.
以丙烯酰胺(AM)和甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体原料,引入复合引发体系和引发促进剂,采用水溶液聚合技术,合成了高分子量阳离子聚丙烯酰胺(CPAM)。考察了引发促进剂用量、引发剂浓度、单体含量、聚合方式(绝热聚合和恒温水浴聚合)及pH值等因素对聚合速率和相对分子质量的影响,并探讨了CPAM在各种无机盐溶液中的黏性行为。结果表明,合成CPAM的最佳条件:采用绝热聚合方式,引发剂及引发促进剂用量分别为0.25×10—3g.gm-1、5.0×10-6g.gm-1,单体质量分数30%,pH值5.0;CPAM在NaCl溶液和(NH4)2SO4溶液中均表现出典型的普通聚电解质黏性行为,而在CaCl2溶液中表现出非典型的普通聚电解质黏性行为。  相似文献   

13.
反应型乳化剂作用下的丙烯酸酯共聚物乳液   总被引:1,自引:1,他引:1  
采用反应型乳化剂1-丙烯基-2-羟基烷磺酸钠(COPS-Ⅰ)与阴离子乳化剂聚氧乙烯-4-酚基醚硫酸铵(CO-436)复配乳化体系,制备了丙烯酸酯共聚物核壳乳液,主要探讨了不同的制备方法、不同单体(甲基丙烯酸甲酯MMA、苯乙烯St、丙烯酸丁酯BA、丙烯酸AA)的用量、引发剂过硫酸铵(APS)的用量、种子乳液用量以及乳化剂COPS-Ⅰ与CO-436配比等因素对乳液和乳胶膜性能的影响。测试结果表明,当采用半连续种子乳液聚合方法,MMA∶St∶BA∶AA质量比为18∶16∶14∶1,种子乳液的质量为10%,COPS-Ⅰ与CO-436质量比为4∶1,APS的质量为0.5%~0.7%时,得到的丙烯酸酯共聚物乳液和乳胶膜的综合性能较好。  相似文献   

14.
Fluororesin-based anti-corrosive coatings including graded FEP/PPS were prepared on carbon steel by melt powder coating, the bonding strength of all coating systems was determined by the pull-off test. It is found that the poor adhesion of fluororesin coatings to metallic substrates is improved obviously by the graded coating structure of FEP/PPS, and the bonding strength reaches up to 11.8 MPa for the five-layer system. Examination by electron probe microanalysis (EPMA) verifies that the distribution of main components is graded in the five-layer system, which is responsible for the enhancement of the interfacial bonding.  相似文献   

15.
镍基纳米碳管/二氧化钛复合镀层的制备及性能   总被引:1,自引:0,他引:1  
为了改善金属基材的表面性能,以钛铁矿为原料,利用微波等离子体化学气相沉积法制备了纳米碳管/二氧化钛复合粉体.采用复合电泳电沉积法在不锈钢基体表面制备了镍基纳米碳管/二氧化钛复合镀层;利用扫描电镜、X射线衍射仪、数显维氏硬度计和电化学测试等手段研究了纳米碳管/二氧化钛复合粉体对复合镀层结构和性能的影响.结果表明纳米碳管/二氧化钛复合粉体的加入有效地减小了复合镀层中镍的晶粒尺寸,促进了金属镍沿(111)晶面择优取向生长,改变了镍的电沉积层结构,提高了镀层的硬度,改善了镀层的耐腐蚀性能;在复合粉体的作用下,复合镀层的硬度与纯镍镀层相比提高了110%,腐蚀电位正移了23mV,腐蚀电流密度减少了0.991微安/平方厘米.  相似文献   

16.
以Span60和马来酸酐为原料,合成了一种马来酸酯类可聚合乳化剂(MPE),并将其应用于淀粉接枝丙烯酰胺乳液反相聚合反应中,探讨了引发剂浓度等反应条件对可聚合乳化剂的转化率以及接枝率等指标的影响。实验表明,以MPE作为乳化剂的淀粉接枝丙烯酰胺反应的最佳反应条件为:引发剂浓度为2.0×10-4mol/L;引发剂过硫酸铵与尿素配比为1.0∶1.5,接枝聚合反应的单体转化率可达到69.32%;MPE质量浓度为82 g/L较合适,最佳反应时间为4 h,反应温度为55℃。  相似文献   

17.
文章介绍了钢结构防腐的方法及工艺,评价了各种方法的效果指出了注意事项.  相似文献   

18.
以Span60和马来酸酐为原料,合成了一种马来酸酯类可聚合乳化剂(MPE),并将其应用于淀粉接枝丙烯酰胺乳液反相聚合反应中,探讨了引发剂浓度等反应条件对可聚合乳化剂的转化率以及接枝率等指标的影响. 实验表明,以MPE作为乳化剂的淀粉接枝丙烯酰胺反应的最佳反应条件为引发剂浓度为2.0×10-4mol/L;引发剂过硫酸铵与尿素配比为1.0∶1.5,接枝聚合反应的单体转化率可达到69.32%;MPE质量浓度为82 g/L较合适,最佳反应时间为4 h,反应温度为55 ℃.  相似文献   

19.
以环氧树脂、丙烯酸、马来酸酐为原料合成水性光敏树脂。讨论了催化剂用量、反应温度、反应时间等因素对合成水性光敏树脂性能的影响。并初步研究了其在纸张湿部添加中的应用工艺,对其影响因素进行了讨论。结果显示:经过水性光敏树脂涂布后,纸张的物理性能得到了明显的改善。  相似文献   

20.
纳米材料技术在涂料产业中的应用现状与发展趋势   总被引:9,自引:0,他引:9  
介绍了纳米材料,纳米技术在涂料工业中的应用及其对涂料的改性作用,阐述了纳米材料及其技术应用于涂料中的意义,对国内外纳米材料及其技术在改造涂料产业中的研发现状进行了综述,分析了纳米材料及其在技术应用在涂料中的主要问题,并针对其发展趋势进行了展望。  相似文献   

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