含酰胺基Gemini阳离子表面活性剂的合成及性能

以棕榈酸、N,N-二甲基丙二胺、环氧氯丙烷和脂肪胺为原料合成了一系列Gemini阳离子表面活性剂.用红外光谱、质谱对产品进行了结构分析,并对产品性能进行了测定.结果表明:所合成的Gemini阳离子表面活性剂的临界胶束浓度低于传统阳离子表面活性剂十六烷基三甲基溴化铵(CTAB)1-2个数量级;当浓度为1×10-3mol/...     

一种非离子型含氟聚氨酯表面活性剂的合成及性能

以甲苯-2,4-二异氰酸酯(2,4-TDI)、2-甲氧基-3-全氟壬烯氧基丙醇和聚乙二醇(PEG)等为主要原料,通过分布缩合得到一种非离子型含氟聚氨酯表面活性剂,并利用红外光谱对其进行了表征。讨论了加料方式、亲水单体相对分子质量、聚乙二醇用量等因素对产品性能的影响。实验结果表明,当n(2,4-TDI):n(氟醇):n(PEG)=1:1:1.1时,采用先加入TDI和氟醇,反应一段时间后滴加PEG的加料方式,能够合成得到综合性能较好的非离子型含氟聚氨酯表面活性剂。对该表面活性剂在水相中的表面活性进行了测试,所制得的非离子型含氟聚氨酯表面活性剂(FPU-1)的相对分子质量为1310,其临界胶束浓度约为9.54×10-5mol/L,水溶液的最低表面张力为20.88mN/m。     

双子表面活性剂的合成及其表面活性

在四丁基溴化铵催化下,正十二醇、正十四醇和正十六醇分别与环氧氯丙烷反应制得1-烷氧基-3-氯异丙醇(3a～3c);3与四甲基乙二胺反应制得双子阳离子表面活性剂4a-4c;4依次通过磺化与中和反应合成了双子两性离子表面活性剂1a～1c,其结构经IR确证.研究结果表明,1和4在室温(25℃)均具有较高的乳化能力;只是1相对...     

一种Gemini表面活性剂合成及其在薄膜中的应用

通过硬脂酸乙酯、甲酸乙酯、1,2-二溴乙烷、无水乙醇、金属钠、二聚甘油等原料合成非离子Gemini表面活性剂-Gemini硬脂酸二聚甘油酯(PGGE)。利用红外光谱、核磁共振氢谱对其进行了结构表征。测试了其性能,并与单硬脂酸二聚甘油酯(PGME)进行了比较。结果表明,该PGGE表面活性剂γcmc为31.1 mN.m-1,cmc为0.0039 mmol.L-1。将其用在农用塑料薄膜上,考察了其防雾滴性能,应用实验表明,该表面活性剂是一种性能优良的塑料薄膜防雾滴剂。     

基于丙二酰胺的不对称双子表面活性剂的合成及其乳化性能

将二(3-二甲氨基丙基)丙二酰胺分别与溴代十六烷和溴代十四烷反应,生成的季铵盐化产物经丙酮-乙腈重结晶,得到含丙二酰胺基的不对称阳离子双子(Gemini)表面活性剂(命名为16-9-14),总收率为45.9%(以溴代十六烷计);利用红外光谱和核磁共振谱表征了合成产物的结构,采用电导法测定了其临界胶束浓度(CMC),采用滴体积法测定了其临界张力(γCMC),进而初步探讨了其发泡沫性能和乳化性能.结果表明,合成的Gemini表面活性剂的CMC为1.57×10-4 mol/L,γCMC为38.45mN/m;其发泡性能和乳化性能优于相应的单子表面活性剂.     

双酯基型Gemini表面活性剂的合成及其性能

以1,4-环己二醇、氯乙酰氯、长链叔胺(RN(CH_3)_2,R=10、12、14、16)为原料,合成了一系列不同长度烷基链的双酯基型Gemini表面活性剂(分别命名为C10-EG-10、C12-EG-C12、C14-EG-C14、C16-EG-C16),用FTIR、NMR(~1H、~(13)C)对中间体及产物进行了表征,并研究了表面活性剂的表面性能及抑菌能力。结果表明:在298.15K时,采用铂金环法测定了合成的4种不同长度烷基链Gemini表面活性剂的临界胶束浓度,C10-EG-C10、C12-EG-C12、C14-EG-C14、C16-EG-C16的CMC值分别为5.495、1.096、0.186、0.045 mmol·L~(-1),与传统单链季铵盐表面活性剂相比,合成的Gemini表面活性剂具有较低的CMC值。胶束化热力学参数结果表明在形成胶束过程中是自发放热的。对合成的4种表面活性剂进行了乳化性能、起泡性能和抑菌测试,C14-EG-C14表面活性剂具有很好的乳化能力;C16-EG-C16 Gemini表面活性剂具有良好的稳泡能力;C10-EG-C10表面活性剂具有良好的抑菌能力。     

新型孪尾Gemini两性离子表面活性剂应用性能

分别采用改进的Ross-Miles法及分水时间法,对3种新型孪尾Gemini两性离子表面活性剂(C8C8L3Sz、C8C8L4Sz和C10C8L3Sz)的泡沫性能及乳化性能进行了研究,并考察了表面活性剂浓度、分子结构和温度等对其的影响。 结果表明,该系列表面活性剂具有较好的泡沫性能,且随其浓度的增加,泡沫最大高度和半衰期均存在一个稳定值,疏水链越长,其起泡性能越差,泡沫稳定性越好;温度升高,起泡性能变好,泡沫稳定性变差;当表面活性剂浓度一定时,体系中加入低浓度的短链醇及无机盐均能提高泡沫的稳定性;C8C8L3Sz、C8C8L4Sz和C10C8L3Sz作乳化剂的最适宜的用量分别为6×10-4、6×10-4和4×10-4 mol/L,疏水基越长,乳化性能越好,而连接基对其影响较小;温度升高,乳化性能变差;当油相烷烃碳数相同时,环烷烃要比直连烷烃更易达到最佳乳化效果,但二者的乳状液稳定时间相当;对于油相烷烃碳数不同时,烷烃的碳链越长,乳状液的稳定性越差,乳化效果越不好。     

二氯化-N,N-′-二(3-脱氢松香酰氧-2-羟丙基)四甲基乙二胺的合成与性能

研究了Gemini表面活性剂中疏水"尾巴"结构对性质的影响,以脱氢松香酸和环氧氯丙烷为原料合成了中间体3-脱氢松香酰氧-2-羟丙基氯,再与四甲基乙二胺反应,得到1种以脱氢松香酰基为疏水链"尾巴"的对称Gemini型双季铵盐阳离子表面活性剂:二氯化-N,N′-二(3-脱氢松香酰氧-2-羟丙基)四甲基乙二胺。在合成工艺条件的基础上,采用IR光谱、MS谱和元素分析测试技术对产物进行了结构确认。结果表明,该产物可降低水的表面张力达34.9 mN/m,临界胶束浓度为1.0×10-4mol/L。表明具有良好疏水性能的2个大"尾巴"使合成的Gemini表面活性剂更易形成胶束,大大提高了表面活性。     

二氯化-N,N-'-二(3-脱氢松香酰氧-2-羟丙基)四甲基乙二胺的合成与性能

研究了Gemini表面活性剂中疏水"尾巴"结构对性质的影响,以脱氢松香酸和环氧氯丙烷为原料合成了中间体3-脱氢松香酰氧-2-羟丙基氯,再与四甲基乙二胺反应,得到1种以脱氢松香酰基为疏水链"尾巴"的对称Gemini型双季铵盐阳离子表面活性剂二氯化-N,N'-二(3-脱氢松香酰氧-2-羟丙基)四甲基乙二胺.在合成工艺条件的基础上,采用IR光谱、MS谱和元素分析测试技术对产物进行了结构确认.结果表明,该产物可降低水的表面张力达34.9 mN/m,临界胶束浓度为1.0×10-4 mol/L.表明具有良好疏水性能的2个大"尾巴"使合成的Gemini表面活性剂更易形成胶束,大大提高了表面活性.     

支链醇对Gemini表面活性剂表面活性和胶束化行为的影响

Gemini表面活性剂是一类高效的新型表面活性剂,而醇是工业界和日化领域最常采用的表面活性剂助剂,因此研究不同结构的醇对Gemini表面活性剂表面活性和胶束化行为的影响规律和机理对于促进Gemini表面活性剂的发展和实际应用具有重要意义.利用表面张力、电导、等温滴定微量热,低温透射电镜和核磁共振研究了直链醇1-戊醇和具有相同主链的支链醇2-己醇与3-庚醇对具有不同长度连接基团阳离子季铵盐型Gemini表面活性剂C₁₂C_SC₁₂Br₂ （S=2,4,6,8,10,12）的表面活性和胶束化行为的影响,结果发现,支链醇能够显著影响表面活性剂在气/液界面的排布,使得C₂₀ （使溶剂的表面张力降低20 mN/m所需的表面活性剂浓度）和γ_CMC （CMC时表面张力值）随醇支化度的增加而显著降低,而支链醇对表面活性剂在溶液中的临界胶束浓度以及胶束的尺寸和形貌均没有明显影响,同时这些醇对Gemini表面活性剂的影响与连接基团的长度相关.阐述了上述结果产生的机理,将有助于指导如何选择合适结构的醇助剂去调控Gemini表面活性剂的表面和溶液性质.     

两性离子表面活性剂的合成及其表面性质

合成了一类含季铵基和磺酸基结构的非对称Gemini两性离子表面活性剂;利用红外光谱、质谱、离子定性试验验证了合成产物的分子结构,并测定了其表面性质.结果表明,目标产物的分子结构符合设计预期;五种非对称Gemini两性离子表面活性剂的表面张力在30mN/m左右,临界胶束浓度达到10-4~10-5数量级.此外,虽然非对称Gemini两性离子表面活性剂的起泡性能比相应单链型表面活性剂的稍差,但其稳泡性明显优于后者.     

Microcellular foams from polyethersulfone and polyphenylsulfone: Preparation and mechanical properties

Polymeric foams having microcellular structures were successfully prepared from some high-performance thermoplastics, specifically polyethersulfone and polyphenylsulfone. A two-stage batch foaming process was used and the resulting materials had average cell sizes in the range 2-13 μm, and cell densities the order of 10¹⁰-10¹¹ cells/cm³. The foam densities (relative to those of the unfoamed polymers) were in the range 0.90-0.35. Average cell sizes increased with foaming temperature and foaming time; on the other hand, cell densities and relative foam densities decreased slightly with foaming temperature but remained almost constant with foaming time. Experimental values of Young’s modulus in compression and the elastic collapse strength were higher than theoretically predicated at high relative densities, but the discrepancies became small at lower densities. In contrast, Young’s moduli in tension were in very good agreement with theory, but the relative strengths were somewhat lower than predicated.     

Physicochemical properties of series of cardanol polyoxyethylene ether carboxylates with different ethoxylation unit at the interface

Series of cardanol polyoxyethylene ether carboxylates were synthesized with biomass cardanol as material to study their physicochemical properties at the interface. The surface tensions of the cardanol nonionic-anionic surfactants were measured at 25?°C and the thermodynamic parameters of adsorption were also calculated. The surface activity and thermodynamic properties of the cardanol nonionic-anionic surfactants were correlated to their chemical structures. With increasing of the number of the ethoxylation unit in the hydrophilic group, a decrease in adsorption efficiency and an increase in surface tension at critical micelle concentration and thermodynamic free energy of adsoption were observed and were attributed to a decrease in adsorption of the cardanol nonionic-anionic surfactants at the interface. Series of the cardanol nonionic-anionic surfactants have good wettability and foaming property. The foaming capacity and the foaming stability of the solution of the cardanol nonionic-anionic surfactants increase by decreasing in the ethoxylation unit and by increasing the double bond of the hydrophobic group. The physicochemical properties of the cardanol nonionic-anionic surfactants at the interface are correlated to the chemical structures of the investigated surfactants, and there is the synergy effect between the nonionic hydrophilic group and the anionic hydrophilic group at the interface.     

Effects of Modified MMT on Mechanical Properties of EVA/MMT Nanocomposites and Their Foams

In this study, nanocomposites of poly(ethylene-co-vinyl acetate) with two kinds of organically modified montmorillonite (OMMT) were prepared by melt intercalation. Their structures and mechanical properties were characterized by X-ray diffraction (XRD) and tensile test respectively. Especially, foaming of these nanocomposites mixed with chemical blowing agent was carried out through compression molding. Influences of OMMT on foaming ratio and mechanical properties were investigated by density test, tensile test and tear test. Results revealed that both kinds of OMMT with proper content increased tensile strength and Young's modulus of nanocomposites without a compromise of elongation at break. For foaming, OMMTs apparently improved foaming ratio and in particular, one of them can improve tear strength, tensile strength, Young's modulus and elongation although the density was decreased.     

多孔酚醛树脂热解碳材料的制备与结构

用苯酚和甲醛在氨水催化下合成了可溶性酚醛树脂, 经掺杂不同质量比发泡剂(氯化锌)后在惰性气氛下进行热裂解(500～900 ℃), 制备了多孔热解碳导电材料(PPAS); 用FTIR, XRD, TG, SEM, BET等方法对所制备材料进行了结构表征, 详细讨论了发泡剂的加入对热解碳导电材料结构和性能的影响. 研究发现: 酚醛树脂经掺杂一定量发泡剂后再进行热裂解, 一方面加快了酚醛树脂分子间的脱水速度, 降低了热裂解温度范围; 另一方面, 裂解产物内部结构的微晶尺寸和层间距发生了明显变化, 未掺杂发泡剂的裂解产物呈现尖锐棱角的无定形结构, 而掺杂发泡剂的裂解产物则为多孔的球形和椭球形结构; 表面吸附实验测试结果表明, 当酚醛树脂与发泡剂的质量比为1∶3, 升温速率为30 ℃/h, 热裂解温度为600 ℃时, 热裂解产物的比表面积可达2150 m2•g－1, 平均孔径在11 Å左右.     

Morphology and characterization of 3D micro-porous structured chitosan scaffolds for tissue engineering

This research studies the morphology and characterization of three-dimensional (3D) micro-porous structures produced from biodegradable chitosan for use as scaffolds for cells culture. The chitosan 3D micro-porous structures were produced by a simple liquid hardening method, which includes the processes of foaming by mechanical stirring without any chemical foaming agent added, and hardening by NaOH cross linking. The pore size and porosity were controlled with mechanical stirring strength. This study includes the morphology of chitosan scaffolds, the characterization of mechanical properties, water absorption properties and in vitro enzymatic degradation of the 3D micro-porous structures. The results show that chitosan 3D micro-porous structures were successfully produced. Better formation samples were obtained when chitosan concentration is at 1–3%, and concentration of NaOH is at 5%. Faster stirring rate would produce samples of smaller pore diameter, but when rotation speed reaches 4000 rpm and higher the changes in pore size is minimal. Water absorption would reduce along with the decrease of chitosan scaffolds’ pore diameter. From stress–strain analysis, chitosan scaffolds’ mechanical properties are improved when it has smaller pore diameter. From in vitro enzymatic degradation results, it shows that the disintegration rate of chitosan scaffolds would increase along with the processing time increase, but approaching equilibrium when the disintegration rate reaches about 20%.     

Study on Foaming Properties and Dynamic Surface Tension of Sodium Branched-alkyl Benzene Sulfonates

Foaming properties and the dynamic surface tension (DST) were carried out with aqueous solutions of sodium branched-alkyl benzene sulfonates to elucidate the relationship between foaming properties and surfactant structures. The parameters of the DST (t*, n, R _1/2 ) are correlated with the foaming ability for alkyl benzene sulfonates with benzene ring substituting at positions 2, 4, and 8 of hexadecane. The parameters of the DST (t*, n, R _1/2 ) are correlated with the foaming ability of the same surfactant solutions. The results indicated that the molecular diffusion in the solution, adsorption, and arrangement at the air/water interface were changed with different molecular structures: changing the substituted position of benzene ring from 2 to 8 of hexadecane, the value of t* and n decrease, and the value of R _1/2 increases, which lead to the high dynamic surface activity and high foam volume. The foam stability is correlated with the high surface dilational elasticity and the strength of surface monolayer: changing the substituted position of benzene ring from 2 to 8 of hexadecane, the branched-alkyl chain becomes more flexible, which is characterized by densely packed adsorbed molecules and high film elasticity of the adsorption film. Therefore, the foam stability increases.     

烷基-β-D-吡喃葡萄糖苷的合成与性能

以葡萄糖为原料,经乙酰化、选择性脱C1位乙酰基、转化成三氯乙酰亚胺酯、与受体醇偶联和脱保护5步反应合成了11种不同碳链长度的烷基β-D-吡喃葡萄糖苷。 利用核磁共振、偏光显微镜和热失重分析法对其进行结构表征和性能测试。 结果表明,当烷基β-D-吡喃葡萄糖苷疏水烷基链长n为 6~10时,均具有发泡和乳化性能,特别是正壬基β-D-吡喃葡萄糖苷(n=9)具有更加优异的发泡和乳化性能;当烷基β-D-吡喃葡萄糖苷疏水链的长度n≥7时,均具有热致液晶行为,特别是正十二烷基β-D-吡喃葡萄糖苷(n=12)和十四烷基β-D-吡喃葡萄糖苷(n=14)能够形成更加稳定的液晶态。     

Surface-active properties of a series of 1,1-dimethyl-1-alkylhydrazinium chlorides

The surface-active properties of a series of 1,1-dimethyl-1-alkylhydrazinium chlorides with C₁₀–C₁₈ in length were studied in comparison with Neonol AF 9–12 and Oksifos B surfactants. The limiting wetting angle, detergent and solubilization power, and foaming kinetics of these surfactants were studied in relation to the concentration of formation of monomolecular layer and type of the resulting micellar structures.     

Resistivity-Temperature Behavior of CB-Filled HDPE Foaming Composites

High-density polyethylene/carbon black foaming conductive composites were prepared from acetylene black（ACEY） and super conductive carbon black（HG-1P） as conductive filler, low-density polyethylene（LDPE） as the second component, ethylene-vinyl acetate（EVA） and ethylene propylene rubber（EPR） as the third component, azobisformamide（AC） as foamer, and dicumyl peroxide（DCP） as cross-linker. The structure and resistivity-temperature behavior of high-density polyethylene（HDPE）/CB foaming conductive composites were investigated. Influences of carbon black, LDPE, EVA, EPR, AC, and DCP on the foaming performance and resistivity-temperature behavior of HDPE/CB foaming conductive composites were also studied. The results reveal that HDPE/CB foaming conductive composite exhibits better switching characteristic; ACET-filled HDPE foaming conductive composite displays better positive temperature coefficient（PYC） effect; whereas super conductive carbon black（HG-1P）-filled HDPE foaming conductive composite shows better negative temperature coefficient（NTC） effect.