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1.
根据表面与界面化学的相关原理,采用DCAT21型动态接触角/表面张力仪测量了常用键合剂、RDX、HTPB在不同探针液体中的接触角,通过接触角计算键合剂、RDX、HTPB的表面自由能及其分量。并计算了键合剂-RDX、键合剂-HTPB界面之间的黏附功。通过扫描电镜观察添加不同键合剂后RDX与HTPB的黏接状态。由黏附功数据和扫描电镜的观察结果可以得出结论:键合剂LBA603对RDX-HTPB界面的改善作用最好。  相似文献   

2.
为了解推进剂中黏合剂与固体填料之间的界面性能,以端环氧聚丁二烯(ETHTPB)为黏合剂,以Al(铝粉)、AP(高氯酸铵)、RDX(黑索金)和HMX(奥克托金)为填料,采用动态接触角测量仪和界面张力仪对黏合剂与固体填料之间的性能(如接触角、表面张力、界面张力、黏附功和铺展系数等)进行了表征和计算。研究结果表明:ETHTPB的表面张力较小,在固体推进剂组分表面易铺展;ETHTPB与固体填料之间的黏附功大小依次为Wa(ETHTPB-AP)Wa(ETHTPB-RDX)Wa(ETHTPB-HMX)Wa(ETHTPB-Al),ETHTPB与固体填料之间的铺展系数大小依次为SSL(ETHTPB-AP)SSL(ETHTPB-RDX)SSL(ETHTPB-HMX)SSL(ETHTPB-Al)。  相似文献   

3.
制备了含硼丁羟(HTPB)胶片,通过扫描电镜(SEM)分析了胶片断面形貌,并采用庞氏kv值法考察了B/HTPB黏合剂基体的界面作用,结果显示B/HTPB黏合剂基体界面作用良好。通过傅里叶红外(FT–IR)光谱分析,B与HTPB黏合剂基体界面作用机理为B与—NHCOO—基团中C—O键的O存在配位作用,这增强了B/丁羟聚氨酯界面作用。  相似文献   

4.
接触角法研究PVC/包覆CaCO3复合材料性能   总被引:1,自引:0,他引:1  
在常温下,测定了几种已知表面张力参数的液体与聚氯乙烯(PVC)/包覆CaCO3复合体系间的接触角,计算了粘合功、Harkins铺展系数,结果表明:随着上述两参数的增加,CaCO3颗粒更容易在PVC基体中分散:Molar实验和扫描电子显微镜观察冲击断面,证实了热力学计算结果。  相似文献   

5.
采用氢化改性端羟基聚丁二烯(H-HTPB)、二环己甲烷-4,4'-二异氰酸酯(HMDI)和对苯二酚二羟乙基醚(HQEE)为原料合成了H-HTPB型聚氨酯弹性体,并与HTPB型聚氨酯弹性体比较。在pH值为7.4的85℃缓冲溶液中进行了加速水解老化试验。采用扫描电镜、凝胶渗透色谱、接触角测量仪与万能拉伸试验机等表征手段对其性能进行了表征。结果表明,与HTPB型聚氨酯相比,H-HTPB型聚氨酯弹性体的水接触角由84.8°增加到98.8°,杨氏模量与拉伸强度较高,伸长率与断裂回复率较低。水解老化后H-HTPB型聚氨酯的力学性能以及表面受水解老化的影响较小,说明H-HTPB型聚氨酯的水解老化性能比HTPB型聚氨酯好。  相似文献   

6.
赵庆仁  黄毅萍 《精细化工》2021,38(12):2586-2592
以端羟基聚丁二烯(HTPB)、聚己二酸新戊二醇酯(PNA)、异佛尔酮二异氰酸酯(IPDI)为主要原料制备了一系列水性聚氨酯乳液.采用FTIR、XRD、SEM对胶膜的结构及形貌进行了表征,对乳液性能、胶膜的吸水率、力学性能及胶膜在双向拉伸聚丙烯(BOPP)薄膜上的剥离强度进行了测试,通过胶膜与水、乙二醇、二碘甲烷的接触角测试计算了胶膜的表面能.结果表明,随着HTPB含量的增加,乳液粒径逐渐增大、胶膜表面能大致呈逐渐减小趋势.当HTPB含量为PNA物质的量的30%时,水性聚氨酯乳液综合性能最好,平均粒径为287.3 nm,胶膜表面能为31.77 mJ/m2,拉伸强度为14.20 MPa,断裂伸长率为977.72%,在BOPP薄膜上的剥离强度为4.4 N/25 mm.以该乳液配制的油墨满足GB/T 26394—2011《水性薄膜凹印复合油墨》对油墨黏度13~50 s的要求,且具有良好的初干性和抗粘连性,可满足日常使用.  相似文献   

7.
黄蒙  丁黎  常海  周静  张俊林 《火炸药学报》2020,43(2):203-207,212
为了探索HTPB/Al/AP/RDX复合推进剂组元之间的相互作用,用DSC和TG-DTG方法以及分解反应动力学计算研究了递增组元的4个混合体系(包括HTPB黏合剂体系、HTPB/Al、HTPB/Al/AP和HTPB/Al/AP/RDX推进剂体系)中各组元之间的相互作用。结果表明,DTG峰温以及反应速率常数k可以表征各组元之间的相互作用,其DSC和TG过程可以分为3个阶段;除Al外,各组元之间存在相互作用,各阶段的质量损失测定值与按组分含量计算的加合值吻合得相当好,表明各组元并没有明显的跨阶段分解;AP与HTPB黏合剂的分解温度区间接近或部分重叠,在HTPB/Al/AP和HTPB/Al/AP/RDX的混合体系中发生了强烈氧化还原作用:四组元体系中RDX在200℃及220℃的速率常数k分别为1.53和6.81s-1,均大于单质RDX在同一温度下的速率常数1.33×10-6和1.06×10-5s-1,说明AP可以加速RDX的分解,但RDX对AP或(AP+HTPB)分解的影响呈现复杂的情况,由于HTPB/Al/AP和HTPB/Al/AP/RDX两体系中AP与HTPB的共同分解过程中存在“等动力学点”(308.0℃),温度低于此点时(AP+HTPB)分解速率常数k因RDX存在而下降,而当温度高于此点时则该k值因RDX存在而增大。通过RDX分解机理解释了存在这种现象的原因。  相似文献   

8.
论述了表面活性剂的润湿机理,测定了13种表面活性剂在不同浓度下的表面张力和0. 1%浓度下的界面张力,重点研究了氟碳两性表面活性剂F1157与非离子碳氢表面活性剂XL-50、TMN-6、APG-0810以及与甜菜碱类两性表面活性剂BS-8、BS-12、CAB的配伍增效能。从表面张力、界面张力和铺展面积得出最佳增效配比。当F1157和XL-50的质量比为1:(6~8)时,界面张力降至0. 4 m N/m;当F1157和TMN-6的质量比为1∶(6~10)时,界面张力降至0. 24 m N/m;当F1157和APG0810的质量比为1∶(3~10)时,界面张力降至0. 063 m N/m。F1157与碳氢甜菜碱的增效性表现在铺展面积优于非离子,同碳数的F1157和BS-8质量比为1∶5时,铺展面积达到最大值99 mm~2。为降低氟碳表面活性剂的使用成本、开拓新领域的应用提供参考。  相似文献   

9.
为评价新型高氮化合物3,5-二硝氨基-1,2,4-三唑肼盐(HDNAT)作为固体推进剂组分的应用潜力,采用NASA-CEA软件,在标准条件下(pc∶p0=70∶1),计算了含HDNAT的丁羟推进剂(HTPB)、聚叠氮缩水甘油醚(GAP)推进剂和改性双基推进剂(CMDB)的能量特性。绘制了HTPB/Al/AP/HDNAT推进剂(金属Al的最大质量分数为20%)的标准理论比冲Isp、特征速度C*、燃烧温度Tc、燃气平均相对分子质量Mw的等性能三角图。结果表明,HDNAT单元推进剂的比冲为2 533.0N·s/kg;在HTPB推进剂中,当HDNAT质量分数为50%时,Isp最大为2 658.0N·s/kg,较基础配方提高了326.6N·s/kg;在GAP推进剂中,当HDNAT质量分数为30%时,Isp最大为2 529.0N·s/kg,较基础配方提高了252.7N·s/kg;在CMDB推进剂中,当HDNAT质量分数为27%时,Isp最大为2 593.1N·s/kg,较基础配方提高了57.3N·s/kg。  相似文献   

10.
为了解决聚合物黏结炸药(PBX)中小分子石蜡钝感剂力学性能差、与高分子黏结剂相容性不佳等问题,基于不同壁材石蜡微胶囊(MePW)的合成,采用浇注成型的方法,制备其与石蜡、端羟基聚丁二烯型聚氨酯(HTPB)的复合材料;研究了该复合材料的化学组成、脆断面形貌、表面和界面热力学性质、力学性能,以及它们之间的关系。结果表明,加入MePW可以有效减少石蜡从HTPB基体脆断面脱离,以MF MePW和PS MePW改善效果最佳。与PW/HTPB相比,加入MePW后使材料表面张力(γs)最高降低了14.8012mN/m(60%MF MePW/PW/HTPB),明显提高石蜡与HTPB间的相容性;同时力学性能显著增强,其压缩模量、压缩强度、拉伸模量、拉伸强度和断裂伸长率最高分别提高了10.4kPa(PS-SiO2 MePW)、94kPa(PMMA MePW/PW/HTPB)、44 kPa(MF MePW/PW/HTPB)、519kPa(MF MePW/PW/HTPB)和796.16%(MF MePW/PW/HTPB)。由此可见,4种壁材MePW中,MF MePW对PW/HTPB的改性效果最显著,最有利于其在PBX体系的应用。  相似文献   

11.
The determination of solid surface free energy is still an open problem. The method proposed by van Oss and coworkers gives scattered values for apolar Lifshitz-van der Waals and polar (Lewis acid-base) electron-donor and electron-acceptor components for the investigated solid. The values of the components depend on the kind of three probe liquids used for their determination. In this paper a new alternative approach employing contact angle hysteresis is offered. It is based on three measurable parameters: advancing and receding contact angles (hysteresis of the contact angle) and the liquid surface tension. The equation obtained allows calculation of total surface free energy for the investigated solid. The equation is tested using some literature values, as well as advancing and receding contact angles measured for six probe liquids on microscope glass slides and poly(methyl methacrylate) PMMA, plates. It was found that for the tested solids thus calculated total surface free energy depended, to some extent, on the liquid used. Also, the surface free energy components of these solids determined by van Oss and coworkers' method and then the total surface free energy calculated from them varied depending on for which liquid-set the advancing contact angles were used for the calculations. However, the average values of the surface free energy, both for glass and PMMA, determined from these two approaches were in an excellent agreement. Therefore, it was concluded that using other condensed phase (liquid), thus determined value of solid surface free energy is an apparent one, because it seemingly depends not only on the kind but also on the strength of interactions operating across the solid/liquid interface, which are different for different liquids.  相似文献   

12.
—The zeta potentials of synthetic chalcocite wetted with n-alkanes were determined in doubly-distilled water. Then the relationship between the coverage of the chalcocite surface with n-heptane or n-hexanol and the zeta potential in water was found. Using an empirical relation, the film pressure of n-heptane and n-hexane was determined. Next the dispersive and polar components of the surface free energy were calculated. The value of the dispersive component was also determined by contact angle measurements. The values obtained were 81.0 and 22.7 mJ/m2, for the dispersive and the polar components of the surface free energy, respectively.  相似文献   

13.
采用光学视频接触角测量仪研究了聚(N-异丙基丙烯酰胺)(PNIPAM)微凝胶在相转变前后的亲疏水性变化。结果表明:PNIPAM微凝胶在32℃附近发生了亲水性-疏水性的反转,微凝胶薄膜的接触角变化显著;随温度增加,接触角从31℃时的73.1°到33℃时的83.2°,而表面自由能从38.5 mN/m下降至32.08 mN/m。  相似文献   

14.
Terpolymers composed of methylmethacrylate (MMA), poly(dimethylsiloxanemethacrylate) (PDMSMA) and methoxypoly(ethyleneglycolmethacrylate) (MPEGMA), which have blood compatibility, were blended with poly(methylmethacrylate) (PMMA) in order to improve their mechanical properties. It was expected that low surface free energy components such as the poly(dimethylsiloxane) (PDMS) and methoxy groups of terpolymer would predominate at the blend surface. The adsorptions of PDMS to the blended surfaces were confirmed via X-ray photoelectron spectroscopy (XPS). A large contact angle hysteresis was observed for the blended films via a dynamic contact angle. Advancing contact angles for blended films showed the same values as that of the silicone. The receding contact angles for those blends incorporating PDMSMA-rich terpolymer showed high values and decreased with hot water treatment, while MPEGMA-rich terpolymer blended films exhibited low values and maintained those values after hot water treatment. Adhesion tension relaxations for these blended films were also observed. These phenomena were interpreted to be caused by the reorganization of a hydrophobic segment to the polymer surface or hydrophilic segment to the water/polymer interface so as to decrease the surface or interfacial tension, respectively. Although the mechanical properties slightly decreased with blending of these terpolymers, the blended films could be applied for various practical uses.  相似文献   

15.
Taking advantage of physical models developed by van Oss-Good and Neumann, which describe relations between surface free energy values for solids and wetting liquids, and making use of the contact angle values for Al2O3 and ZrO2 surfaces and standard liquids with known values of surface energy, which were measured by means of the optical goniometer, surface free energy values as well as their components representing long-range interactions and acid–base interactions for the surfaces of the studied solids were evaluated. Analogical calculations were carried out for the comparative polymer materials—PTFE and PET. On the basis of the obtained data, and based on measured contact angle values for PET surfaces with water emulsions, free energy values were determined for newly synthesised polyurethane ionomers as well as for those ionomer emulsions additionally modified with vinyl monomers. It was found that the surface energy values for the synthesised polyurethane emulsions were predominantly affected by the structure of polyol and urethane segments, while the type of ionogenic segments influenced the quantity of acid–base interactions as well as the quantity of dispersal interactions. The effect of interactions between the surface of ceramic powders and aqueous emulsions on applicability of such systems as efficient binders in moulding green ceramic ware was discussed.  相似文献   

16.
A systematic study on the possibility of Young's contact angle determination from Washburn's equation was performed using the so-called thin-layer wicking technique in which the rate of penetration of a liquid into the porous layer of a solid is measured. Commercial (Merck) SiO2 deposited on the glass plate for thin-layer chromatography was used as a model solid and n-alkanes (from pentane to hexadecane), diiodomethane, and α-bromonaphthalene were employed as the probe liquids. It was shown that the contact angle calculated from Washburn's equation was not equal to Young's contact angle of a drop of the same liquid, placed on a flat surface of the solid. Consequently, the solid surface free energy components calculated using contact angles from Washburn's equation are not the true values. However, the approach previously suggested by us has been verified again, as it gives consistent values of the surface free energy components determined from all the liquids used.  相似文献   

17.
The components of the surface free energy (SFE) were determined from static contact angle measurements of five liquids using different methods. The two manufacturing techniques (casting and electrospinning) applied to obtain polyurethane (PU) membranes give surfaces with different wetting properties. The SFE data varied and were strongly dependent on calculations methods and liquids that were used for contact angle measurements. As a whole, the SFE of electrospun PU membrane (PU-N) (~24 mN/m) was slightly higher than that of casting PU membrane (PU-F) (~18 mN/m) with similar chemical compositions. The overall increase in the value of SFE is mainly due to the microstructures with increased surface area and modulations of nanofibers. The results evidence the impact of the PU membrane preparation on the properties of the biomaterial surface. Such structure–properties–function relationship is necessary to lay the groundwork for establishing a set of design criteria to guide the fabrication of synthetic materials.  相似文献   

18.
Adhesion of the oral bacterium Streptococcus sanguis was investigated on two series of surfaces, one solid, non-porous and one porous with a pore diameter centered around 0.2 μm. Each series consisted of four substrates with varying surface free energies: pure aluminum oxide, poly(ethylene glycol) (PEG)-modified aluminum oxide, and two types of silanized aluminum oxide. The surface composition was analyzed by ESCA and the surface free energy and acid-base character were determined by contact angle measurements using water, formamide, and diiodomethane according to van Oss and Good. Contact angle measurements were conducted on non-porous substrates which had been subjected to the same silanization procedure as the porous ones. Untreated aluminum oxide and PEG-modified aluminum oxide were both hydrophilic and gave water contact angles of less than 10°. One silanization procedure gave a surface of intermediate hydrophobicity, with a γtot of 47.5 mN/m; the other gave a strongly hydrophobic surface of γtot = 27.4 mN/m. Adhesion of S. sanguis was measured by using radiolabelled bacteria. It was demonstrated that more bacteria adhered to the porous than to the non-porous substrate and that the PEG treatment, as well as the two silanization procedures, resulted in a decrease in bacterial adhesion, in relation both to the controls treated with aqueous buffer and to surfaces treated with fresh saliva.  相似文献   

19.
Several methods for the determination of both the surface free energy of polymer materials and the conditions necessary to perform contact angle measurements are discussed. The effects of the corona-treatment energy on the surface free energy and on the adhesion of acrylic adhesive were studied using a biaxially-oriented polypropylene film. The surface free energy was determined by the Owens-Wendt, and van Oss-Chaudhury-Good approaches, as well as with the wettability method, using different liquids. The presented results confirm that the surface free energy value depended on both the method used and the nature of probe liquids. Thus, it cannot be considered as a parameter characterizing unambiguously the surface layer of a corona-treated film. The values of the surface free energy for different film samples can be compared with one another only if determined using the same method and the same liquids. The variations of particular components of the surface free energy with the corona-treatment energy depend on e.g. the nature of probe liquids, which makes interpretation of the observed effects difficult.  相似文献   

20.
Total surface free energy, γS TOT, for several solids (glass, PMMA, duralumin, steel and cadmium) was calculated from the surface free energy components: apolar Lifshitz–van der Waals, γS LW, and acid–base electron–donor, γS -, and electron–acceptor, γS +. Using van Oss and coworkers' approach (Lifshitz–van der Waals/acid–base (LWAB) approach), the components were determined from advancing contact angles of the following probe liquids: water, glycerol, formamide, diiodomethane, ethylene glycol, 1-bromonaphthalene and dimethyl sulfoxide. Moreover, receding contact angles were also measured for the probe liquids, and then applying the contact angle hysteresis (CAH) approach very recently proposed by Chibowski, the total surface free energy for these solids was calculated. Although the thus determined total surface free energy for a particular solid was expected to depend on the combination of three probe liquids used (LWAB approach), as well as on the kind of the liquid used (CAH approach), surprisingly the average values of the surface free energy from the two approaches agreed very well. The results obtained indicate that both approaches can deliver some useful information about the surface free energy of a solid.  相似文献   

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