硬段含量对阴/非离子型水性聚氨酯性能影响的研究

以二羟甲基丁酸(DMBA)、聚乙二醇(PEG)为亲水单体,聚氧化丙烯二醇(PPG)为多元醇组分、甲苯二异氰酸酯(TDI)为异氰酸酯组分,采用预聚体法合成了一系列阴/非离子型水性聚氨酯(WPU)。通过万能材料试验机、傅里叶变换红外光谱仪、粒径测试、表面张力测试等分析表征手段研究了硬段含量对阴/非离子型WPU乳液及胶膜性能的影响。结果表明:随着硬段含量的提高,WPU乳液粒径逐渐增加,黏度逐渐下降,表面张力逐渐增大;WPU胶膜的拉伸强度逐渐提高,断裂伸长率逐渐减小。     

水性聚氨酯防水涂膜材料的制备与性能

为了研究多元醇类型对水性聚氨酯防水涂膜材料性能的影响,选用分子量均为1 000的聚酯型、聚醚型多元醇为软段,通过预聚体法制备了一系列水性聚氨酯(WPU)分散体;探讨了WPU的粒径、黏度、结构及结晶性、水抵抗性能。结果表明:制备的WPU分散体粒径较小;聚酯多元醇型[聚己二酸乙二醇酯(PB)、聚碳酸酯(PCL)]WPU膜的拉伸强度、结晶性能高于聚醚多元醇型[聚丙二醇(PPG)、聚四氢呋喃醚二醇(PTMG)]的,但是断裂伸长率低于聚醚多元醇型的WPU膜;其中PTMG型WPU膜的水接触角最大,达到66.5°,吸水率最小(6.2%),防水性最佳,综合性能最好,最适合用作环境友好型纤维织物防水涂膜材料。     

乙二胺对聚醚聚酯混合型水性聚氨酯涂料涂膜性能的影响

为克服单一聚醚或聚酯型聚氨酯的缺点,以聚己二酸-1,4-丁二醇酯二醇(PBA)和聚四氢呋喃醚二醇(PTMG)为混合软段,以异佛尔酮二异氰酸酯(IPDI)和六亚甲基二异氰酸酯(HDI)为混合异氰酸酯,加入不同含量的扩链剂乙二胺(EDA),合成了一系列聚醚聚酯混合型水性聚氨酯(WPU)乳液。采用傅里叶红外光谱、粒径和Zeta电位测试、吸水性和表面接触角测试、力学性能以及热失重分析对乳液及WPU膜的结构与性能进行了表征,研究了EDA含量对WPU涂料涂膜性能的影响。结果表明:随着EDA含量的增加,聚氨酯分子氢键化能力增强,WPU乳液黏度和Zeta电位降低,乳液平均粒径增大且粒径分布范围变宽,WPU膜拉伸强度增强而断裂伸长率减小,WPU膜吸水性增加,耐水性下降,热稳定性得到一定程度的提高。     

阳离子丙烯酸酯共聚物表面活性剂的结构及溶液性能

通过自由基溶液共聚合法合成了无规型阳离子丙烯酸酯共聚物表面活性剂,利用红外光谱(FT-IR)和核磁共振谱(1H-NMR和13C-NMR)对聚合产物的结构和组成进行了表征,考察了浓度、温度等对聚合物丙酮溶液的增比黏度和聚合物水溶液表面张力的影响。结果表明,聚合物丙酮溶液的增比黏度随溶液浓度增加总体呈现上升趋势,在相同溶液浓度下,其增比黏度随温度升高呈先降低后升高再降低的趋势;聚合产物可将水溶液的表面张力降低到43mN/m,其临界胶束浓度为0.8 g/L;聚合物水溶液的表面张力随温升高而降低,且随溶液pH值增大而增大。     

丙烯酸酯水性涂料用高分子乳化剂的合成及性能研究

以甲基丙烯酸、苯乙烯、丙烯酸羟乙酯和丙烯酸-2-乙基己酯为主要原料,通过溶液共聚法合成了用于丙烯酸酯水性涂料的高分子表面活性剂.使用FT-IR对合成产物的结构进行了表征,测试了共聚物的表面张力、临界胶束浓度(CMC)、表观黏度,初步探讨了甲基丙烯酸用量对产物表面活性的影响.结果表明,共聚物的表观黏度(异丙醇溶剂,浓度85%)为100～530 mPa·s,具有较低的临界胶束浓度(CMC)(4～9 g/L),最低表面张力降至31.5mN/m(25℃).以此产物为乳化剂,皆能制得体系稳定的丙烯酸酯乳液,其乳胶粒粒径分布均匀.     

聚醚FF-2改性硅油的合成、结构与性质研究

以聚醚(FF-2)和含氢硅油(PHMS)为原料,制得兼有两者性能的聚醚改性硅油。对合成产物进行了红外表征,测定了其黏度指数(VI)、粘温系数(VTC)和表面张力(ST),讨论了PHMS含氢量和黏度对产物性质的影响。根据计算出的产物的链节比和聚合度,研究了产物分子结构对其粘温系数和表面张力的影响。结果表明:在考察范围内,聚醚改性聚硅氧烷的黏度指数和表面张力都随链节比的增加而增加;随着聚合度的增加,产物黏度指数增加,表面张力变小;二元回归方程很好地预测了聚醚改性硅油的VTC和ST,误差绝对值分别控制在0.0149和0.0650内。     

高硬度单组分水性聚氨酯乳液的制备及性能

以羟乙基双酚A(BPEA)作为水性聚氨酯(WPU)的新型扩链剂,聚环氧丙烷三醇(PPG310)为交联剂,利用透射电镜、热失重分析仪、动态力学分析仪、万能仪、铅笔硬度计对其产物进行了表征。结果表明,所制WPU乳液粒子分散性良好,粒子呈20nm左右球形,聚酯型WPU比聚醚型软硬段相容性高,且储能模量、杨氏模量、铅笔硬度、耐水性能均优于聚醚型WPU。交联后的WPU热稳定性提高,当BPEA质量分数为28.7%,PPG310质量分数为13.6%时,所得涂膜的拉伸强度为49.1MPa,铅笔硬度可达2H,吸水率为6.8%。     

高硬度单组分水性聚氨酯乳液的制备及性能EI北大核心CSCD

以羟乙基双酚A(BPEA)作为水性聚氨酯(WPU)的新型扩链剂,聚环氧丙烷三醇(PPG310)为交联剂,利用透射电镜、热失重分析仪、动态力学分析仪、万能仪、铅笔硬度计对其产物进行了表征。结果表明,所制WPU乳液粒子分散性良好,粒子呈20nm左右球形,聚酯型WPU比聚醚型软硬段相容性高,且储能模量、杨氏模量、铅笔硬度、耐水性能均优于聚醚型WPU。交联后的WPU热稳定性提高,当BPEA质量分数为28.7%,PPG310质量分数为13.6%时,所得涂膜的拉伸强度为49.1MPa,铅笔硬度可达2H,吸水率为6.8%。     

封端剂对聚氨酯分散液性能的影响

目的研究封端剂γ-氨丙基三乙氧基硅烷(KH550)和丙烯酸羟乙酯(HEA)对聚氨酯分散液(WPU)性能的影响。方法采用预聚体法合成聚氨酯分散液,通过傅里叶红外光谱(FTIR)对改性聚氨酯特征官能团进行表征,探讨KH550和HEA用量对聚氨酯分散液粒径大小与分布、表面张力、黏度以及附着力的影响。结果 WPU的粒径随着KH550用量的增加而逐渐增大,且分布变宽,黏度变小;KH550的引入降低了分散液的表面张力;HEA的引入对表面张力的影响较小,WPU的粒径随着HEA用量的增大而逐渐变小,且分布变窄,黏度变大。2种封端剂改性后分散液在PA、PET包装薄膜上表现出了良好的附着力。结论 KH550的引入能够提升水性聚氨酯在薄膜上的附着力,调节分散液黏度。     

聚醚改性三硅氧烷的合成工艺研究

以1,1,1,3,5,5,5-七甲基三硅氧烷和丙烯基聚醚为原料,氯铂酸为催化剂,异丙醇为溶剂,通过硅氢加成反应合成出聚醚改性三硅氧烷。研究了反应温度、物料比、活化温度和时间、催化剂用量、反应时间对七甲基三硅氧烷的转化率的影响,并且对产物的表面张力性能进行测试。得出了较佳反应条件:反应温度100℃、烯丙基聚醚与七甲基三硅氧烷的物质的量比为1.2:1、活化温度60℃、活化时间为30min、氯铂酸相对三硅氧烷的质量分数为0.0015%、反应时间2h。此反应条件下三硅氧烷的转化率为99.34%,临界胶束浓度CMC为1.71×10-4mol/L,临界胶束浓度下的表面张力为20.19mN/m,其水溶液在pH值为5~9的条件下不易分解可以存放1个月。     

相互缠结的聚甲基丙烯酸甲酯/磺化聚苯乙烯复合水基微乳液的研究Ⅰ.复合水基微乳液的制备及影响因素

将聚苯乙烯制成磺化聚苯乙烯离聚体（SPS），利用相反转技术，将磺化聚苯乙烯离聚体加水制成具有纳米级的稳定的水基微乳液，利用SPS纳米微粒核内部作为反应场所，用引发剂引发亲油性单体甲基丙烯酸甲酯聚合，制备具有相互缠结结构的PMMA／SPS复合水基微乳液，研究了引发剂的用量，MMA的用量，溶剂极性对聚合反应及复合水基微乳液的影响。     

相互缠结的PMMA/SPS复合水基微乳液的研究Ⅱ.体系反应前后的粒度分布及形态表征

将聚苯乙烯磺化制成聚苯乙烯离聚体（SPS），利用相反转技术，将磺化聚苯乙烯离聚体制成具有纳米级稳定的水基微乳液，利用SPS微粒核为反应场所，引发另一单体MMA聚合，制备具有相互缠结结构的PMMA／SPS复合水基微乳液。通过粒度分布仪、透射电镜等分析仪器对体系反应前后粒径形态、大小变化进行了探讨；用DSC仪器分析了复合材料的玻璃化转变，发现体系具有良好的相容性。     

新型非离子水性聚氨酯表面活性剂的制备及性能

采用甲苯-2,4-二异氰酸酯(TDI)、蓖麻油和聚乙二醇(PEG)等为主要原料,通过逐步聚合得到一种新型非离子水性聚氨酯表面活性剂,并利用红外光谱对其结构进行了表征。实验结果表明,当蓖麻油∶TDI∶PEG-4000=1∶9∶11时,采用依次加入蓖麻油、TDI、PEG的加料方式,能够合成得到综合性能较好的非离子水性聚氨酯表面活性剂。对该表面活性剂在水相中的表面活性进行了测试,结果表明,所制得的非离子水性聚氨酯表面活性剂的临界胶束浓度约为22 g/L,水溶液的最低表面张力可达53 mN/m。     

Control of Particle Adsorption for Stability of Pickering Emulsions in Microfluidics

Studying the stability of Pickering emulsion is of great interest for applications including catalysis, oil recovery, and cosmetics. Conventional methods emphasize the overall behavior of bulk emulsions and neglect the influence of particle adsorbing dynamics, leading to discrepancies in predicting the shelf‐life of Pickering emulsion–based products. By employing a microfluidic method, the particle adsorption is controlled and the stability of the Pickering emulsions is consequently examined. This approach enables us to elucidate the relationship between the particle adsorption dynamics and the stability of Pickering emulsions on droplet‐level quantitatively. Using oil/water emulsions stabilized by polystyrene nanoparticles as an example, the diffusion‐limited particle adsorption is demonstrated and investigated the stability criteria with respect to particle size, particle concentration, surface chemistry, and ionic strength. This approach offers important insights for application involving Pickering emulsions and provides guidelines to formulate and quantify the Pickering emulsion–based products.     

环氧-聚氨酯复合乳液的合成及表征

以甲苯二异氰酸酯(TDI-80)、聚醚二醇(N220)、二羟甲基丙酸(DMPA)、环氧树脂为主要原料,合成了环氧-聚氨酯复合乳液。主要讨论了环氧树脂对水性聚氨酯乳液及其涂膜性能的影响。实验结果表明,环氧-聚氨酯乳液的表面张力、粘度,涂膜的硬度、耐水性及力学性能随着环氧树脂用量的增大而增强,但乳液外观和稳定性变差,故适宜的环氧树脂添加量为4%～8%。采用傅里叶变换红外光谱、粒径分析仪、凝胶渗透色谱(GPC)、透射电镜(TEM)对乳液和涂膜进行了表征。傅里叶变换红外光谱分析表明,环氧树脂的环氧基和羟基都参与了反应。粒径分析仪和凝胶渗透色谱分析显示,加入环氧树脂后,水性聚氨酯(WPU)分散体粒径和分子量增大,粒径分布和分子量分布均变宽。     

基于海藻酸自组装胶体粒子的制备及其乳化性能

用海藻酸(ALG)和溶菌酶(Lys)静电自组装制备胶体粒子,用纳米粒度仪和透射电镜对其尺寸和形貌进行表征,研究了溶菌酶和海藻酸的质量比(WR)对胶体粒子性质的影响,得到了具有最佳WR的胶体粒子。胶体粒子具有球形结构,粒径约为143 nm。这种胶体粒子可二次组装在油水界面稳定水包油型Pickering乳液,研究了pH值和盐浓度对胶体粒子性质和乳化性能的影响。随着pH值的增大胶体粒子和乳液滴粒径均逐渐增大而乳化性能逐渐降低; 随着盐浓度的提高胶体粒子和乳液滴的粒径先减小后增大,乳化性能先提高后降低。乳液均保留了一定的活性。     

Dissolution of coated microbubbles: The effect of nanoparticles and surfactant concentration

The ability of solid particles to stabilise emulsions is a well known phenomenon which has recently been demonstrated for the stabilisation of gas bubbles. In this paper, a new theoretical model is developed which describes how an adsorbed layer of solid nanoparticles modifies the interfacial tension and diffusivity of a gas bubble in a liquid and hence its stability. In agreement with experimental observations on microbubbles coated with 15 nm diameter spherical gold particles, the results of simulations with the model indicate that the particles substantially decrease the rate at which bubble dissolution occurs and enables them to maintain a stable radius once a critical particle concentration has been reached.     

碳纤维水性杂化上浆剂的制备及其上浆后力学性能

以一定比例的甲基三乙氧基硅烷、正硅酸乙酯、对甲苯磺酸、γ-氨丙基三乙氧基硅烷、无水乙醇制备含硅溶胶,将含硅溶胶和聚醚型水性聚氨酯的水溶液以一定比例复合,制备碳纤维水性杂化上浆剂。研究了不同配比对上浆剂平均粒径和稳定性的影响,结果表明:当水性聚氨酯含量为0.02g/mL时,上浆剂乳液平均粒径为99.94nm,粒径分布较窄,稳定性较好;使用制备的杂化上浆剂对碳纤维进行上浆处理,结果显示:上浆后碳纤维单丝拉伸强度较商用碳纤维提高4.45%,较未上浆碳纤维提高11.04%;与环氧树脂复合后的复合材料界面剪切强度比商用碳纤维增强环氧树脂复合材料的提高了13.74%。     

“Vitamin E” fortified parenteral lipid emulsions: Plackett–Burman screening of primary process and composition parameters

The objective of this study was to screen the effect of eight formulations and process parameters on the physical attributes and stability of “Vitamin E”-rich parenteral lipid emulsions. Screening was performed using a 12-run, 8-factor, 2-level Plackett–Burman design. This design was employed to construct polynomial equations that identified the magnitude and direction of the linear effect of homogenization pressure, number of homogenization cycles, primary and secondary emulsifiers, pre-homogenization temperature, oil loading, and ratio of vitamin E to medium-chain triglycerides (MCT) in the oil phase on particle size, polydispersity index, short-term stability, and outlet temperature of manufactured emulsions. The viscosity of vitamin E was reduced from 3700 (100%) to 64 mPa.s (30%) by MCT addition. As viscosity is critical for efficient emulsification, vitamin/MCT ratio was the most significant contributor for the stability of emulsions. Particle size increased from 236 to 388 nm, and percentage vitamin remaining emulsified after 48 h dropped from 100 to 73% with increase in vitamin/MCT ratio from 30/70 to 70/30. Significant decrease in particle size and PI, and an increase in outlet temperature were also observed with increase in homogenization pressure and number of homogenization cycles. Emulsifiers and oil loading, however, had insignificant effect on the responses. Overall, stable submicron emulsions at vitamin/MCT ratio of 30/70 could be prepared at 25,000 psi and 25 cycles in ambient conditions. The identification of these parameters by a well-constructed design demonstrated the utility of screening studies in the “Quality by Design” approach to pharmaceutical product development.     

Design and development of multiple emulsion for enhancement of oral bioavailability of acyclovir

The objective of this investigation was to design and develop water-in-oil-in-water type multiple emulsions (w/o/w emulsions) entrapping acyclovir for improving its oral bioavailability. Multiple emulsions (MEs) were prepared and optimized using Span-80 and Span-83 as lipophilic surfactant and Brij-35 as hydrophilic surfactant. The physio-chemical properties of the w/o/w emulsions - particle size, viscosity, phase separation (centrifugation test) and entrapment efficiency were measured and evaluated along with macroscopic and microscopic observations to confirm multiple nature, homogeneity and globule size. Stability study, in vitro and ex vivo release studies were performed followed by in vivo studies in rats. Stable w/o/w emulsions with a particle size of 33.098 ± 2.985 µm and 85.25 ± 4.865% entrapment efficiency were obtained. Stability studies showed that the concentration of lipophilic surfactant was very important for stability of MEs. Drug release from the prepared formulations showed initial rapid release followed by a much slower release. In vivo studies in rats indicated prolonged release and better oral bioavailability as compared to drug solution. The overall results of this study show the potential of the w/o/w emulsions as promising drug delivery systems for acyclovir.