封闭型水性聚氨酯预聚体乳液在纸张表面处理中的应用

用咪唑、甲苯-2,4-二异氰酸酯(TDI)和聚乙二醇600(PEG600)合成聚氨酯预聚体乳液,对纸张进行涂布处理,讨论表面涂布量分别为1.2~7g·m-2时,滤纸各项物理性能的变化。结果表明:当滤纸涂布量为7g·m-2时,滤纸的耐折度、撕裂度、抗张强度等物理性能有明显改善,处理后滤纸的湿抗张指数、干抗张指数分别提高到滤纸原纸的19.59倍和1.74倍,耐折度提高了47.05倍。扫描电镜观察可以看出加聚氨酯预聚体乳液进行聚氨酯化后,纸页的纤维间连接了许多丝状和薄膜状物质,这些物质在纤维之间尤其是纤维与纤维交叉的地方形成架桥结构,从而加强了纤维之间的连接。     

封闭型水性聚氨酯在造纸涂布中的应用研究

该文研究了咪唑、甲苯-2,4-二异氰酸酯（TDI）和聚乙二醇（PEG）600形成的聚氨酯预聚体在纸张表面处理中的应用。用咪唑-TDI-PEG 600聚氨酯预聚体（简称LTP600）溶液对纸张进行涂布处理,讨论了表面涂布量分别为4、8、12、16、20和24 g/m2时,滤纸各项物理性能的变化。研究结果表明：当滤纸涂布量为12 g/m2时,滤纸的耐折度、撕裂度和抗张强度等物理性能有明显改善,处理后滤纸的湿抗张指数和干抗张指数分别提高到滤纸原纸的34.11倍和2.71倍,耐折度提高了53.6倍。扫描电镜观察可以看出,加聚氨酯预聚体乳液进行聚氨酯化后,纸页的纤维间连接了许多丝状和薄膜状物质,这些物质在纤维之间尤其是纤维与纤维交叉的地方形成架桥结构,从而加强了纤维之间的连接。     

咪唑封闭型水性聚氨酯乳液对纸张的增强作用研究

本文研究了咪唑、甲苯-24,-二异氰酸酯和聚乙二醇400形成的封闭型水性聚氨酯预聚体经乳化后在纸张涂布以及湿部添加中的应用。用咪唑-TDI-PEG400聚氨酯预聚体乳液对牛皮纸进行涂布处理,讨论了表面涂布量为2g/m2、4g/m2、6g/m2、8g/m21、0g/m2时,牛皮纸各项物理性能的变化。另外,将咪唑-TDI-PEG400聚氨酯预聚体乳液添加到纸浆中,讨论了添加量为2%4、%、6%、8%和10%(相对于绝干浆的量)时,成纸各项物理性能的变化。研究结果表明:纸张涂布牛皮纸时,最适涂布量为4g/m2,此时牛皮纸的抗张指数、湿抗张指数、撕裂指数、挺度分别为空白纸样的1.29倍2、.88倍1、.21倍、1.02倍,湿强保留率达到16.81%。在湿部添加时,当加入量为10%,抄片的抗张指数、湿抗张指数、耐折度、撕裂指数、挺度分别为空白纸样的1.39倍、3.70倍、2.09倍、1.42倍、1.08倍,湿强保留率为15.25%。     

聚氨酯乳液在纸张涂布中的应用研究

将咪唑、甲苯-2,4-二异氰酸酯和聚乙二醇(相对分子质量600)合成的聚氨酯预聚体(咪唑-TDI-PEG600)乳液用于纸张涂布,研究其对纸张物理强度的影响。结果表明,当聚氨酯乳液的涂布量为7 g/m2时,纸张的耐折度、撕裂度、抗张强度等物理性能均有明显改善,涂布后滤纸的湿抗张指数、干抗张指数分别为滤纸原纸的19.6倍和1.7倍,耐折度为滤纸原纸的47.0倍。扫描电镜观察显示,聚氨酯乳液的加入使纸张纤维间连接了许多丝状和薄膜状物质,这些物质在纤维之间尤其是纤维与纤维交叉的区域形成架桥,从而使纤维间的连接更紧密。     

封闭型水性聚氨酯预聚体在纸张表面处理中的应用

本文研究了咪唑、甲苯-2,4-二异氰酸酯和聚乙二醇600形成的封闭型水性聚氨酯预聚体在纸张表面处理中的应用。用咪唑-TDI-PEG600聚氨酯预聚体(简称LTP600)溶液,对滤纸进行涂布处理,讨论了表面涂布量分别为5g/m2、10g/m2、15g/m2、20g/m2、30g/m2和40g/m2时,滤纸各项物理性能的变化。研究结果表明:当滤纸涂布量为15g/m2时,滤纸的耐折度、抗张强度等物理性能有明显改善,处理后滤纸的湿抗张指数和干抗张指数分别提高到滤纸原纸的35.44倍和2.65倍,耐折度提高了54倍。扫描电镜观察可以看出加聚氨酯预聚体进行聚氨酯化后纸页的纤维间连接了许多丝状和膜状物质,这些物质在纤维之间尤其是纤维与纤维交叉的地方形成架桥结构,从而加强了纤维之间连接。     

封闭型水性聚氨酯在造纸湿部的应用

研究咪唑、甲苯-2,4-二异氰酸酯和聚乙二醇600形成的聚氨酯预聚体在造纸湿部添加中的应用。用咪唑-TDI-PEG600聚氨酯预聚体(简称LTP600)溶液,添加到纸浆中,讨论了添加量分别为2%、4%、7%、10%和12%(相对于绝干浆的量)时,成纸各项物理性能的变化。研究结果表明:当LTP600添加量为7%时,成纸的耐折度、抗张强度等物理性能都有明显改善,处理后成纸的湿抗张指数、干抗张指数分别提高到原纸的4.96和2.21倍,耐折度提高了1.44倍。扫描电镜观察可以看出加聚氨酯预聚体进行聚氨酯化后,纸页的纤维间连接了许多丝状和薄膜状物质,这些物质在纤维之间尤其是纤维与纤维交叉的地方形成架桥结构,从而加强了纤维之间的连接。     

添加封闭型水性聚氨酯乳液对纸的增强作用研究

用咪唑-TDI-PEG600聚氨酯预聚体乳液（简称LTP600）添加于纸浆中对纸张进行聚氨酯化处理,讨论了乳液添加量分别为4%、7%、10%、15%和18%时,成纸各项物理性能的变化。采用FT-IR光谱以及电子显微镜观察相结合的方法,分析了所合成的LTP600的物理特性以及表面形态。研究结果表明：当乳液添加量为18%时,成纸的湿抗张指数、干抗张指数、撕裂度和耐折度可分别提高到原纸的5.96倍、1.58倍、1.19倍和1.47倍。FT-IR分析和扫描电镜观察可以证实,聚氨酯预聚体与纤维素的羟基反应生成了氨基甲酸酯结构,纸页的纤维间连接了许多丝状和薄膜状物质,这些物质在纤维之间尤其是纤维与纤维交叉的地方形成架桥结构,从而起到增强作用。     

封闭型聚氨酯预聚体的制备

为制备封闭型聚氨酯预聚体,实验采用聚乙二醇600(PEG600)、咪唑和甲苯二异氰酸酯(TDI)为原料,通过测量反应体系中一NCO的含量,确定预聚反应的最佳时间,合成封闭型聚氨酯预聚体.实验结果表明:当预聚反应时间为2h,PEG/TDI摩尔比为1.25,水分含量在0.04％以下,可以合成出性能较好的聚氨酯预聚体.通过傅立叶红外光谱分析,进一步证明了所合成的产物就是封闭型聚氨酯预聚体.     

TDI—PEG线型遥爪聚合物改善纸张物理性能的研究

本文研究了甲苯－2,4－二异氰酸酯（TDI）与柔性高分子聚乙二醇（PEG）生成线型遥爪聚合物对纸张物理性能的影响,分析了其遥爪聚合物中柔性链对纸张性能的作用。研究结果表明：由于线型遥爪聚合物可以使纸张中的相距较远的纤维之间产生柔性较好的氨基甲酸酯型架桥结构,所以对纸张耐折度、撕裂度、挺度、耐破度、湿强度以及表面强度等物理性能有明显改善。     

淀粉聚氨酯增强剂的合成与应用

以淀粉作为软段,与甲苯-2,4-二异氰酸酯（TDI）反应合成聚氨酯预聚体,然后用咪唑作为封端剂,再进行乳化,最后进行湿部添加实验。结果表明,纸张的抗张强度和耐破度随淀粉聚氨酯添加量增加而提高,随pH的升高而下降,但纸张的耐折度随淀粉聚氨酯的加入而降低。     

Effect of polymeric additives on the formation and properties of polyaniline films on polyester fabrics

Electrically conductive films based on polyaniline (PANI) and polyethylene glycol (PEG) molecules of different chain length were synthesized on polyester textiles (PET) through in situ polymerization. Fabric supports were placed in the monomer bath in the presence of polymeric additive firstly and then immersed into the oxidant solution to initiate the reaction. Influence of the PEG segment length on monomer adsorption process toward fabrics was investigated by comparing the adsorption thermodynamic parameters. The polymeric layers’ morphologies have been evaluated using the field emission scanning electron microscope, and the film formation mechanism has been investigated. Compositions of the films synthesized in the absence and presence of PEG were characterized by attenuated total reflection Fourier transform infrared. The electrical resistance measurement results indicated that the electrical conductivity of PET/PANI–PEG composite fabrics decreases slowly as the PEG segments length increased, and the thermal stability was improved slightly according to thermogravimetric analysis values.     

Thermal and rheological properties of L-polylactide/polyethylene glycol/silicate nanocomposites films

The melt rheology and thermal properties of polylactide (PLA)-based nanocomposite films that were prepared by solvent casting method with L-PLA, polyethylene glycol (PEG), and montmorillonite clay were studied. The neat PLA showed predominantly solid-like behavior (G' > G″) and the complex viscosity (η*) decreased systematically as the temperature increased from 184 to 196 °C. The elastic modulus (G') of PLA/clay blend showed a significant improvement in the magnitude in the melt, while clay concentration was at 6% wt or higher. At similar condition, PEG dramatically reduced dynamic modulii and complex viscosity of PLA/PEG blend as function of concentration. A nanocomposite blend of PLA/PEG/clay (74/20/6) when compared to the neat polymer and PLA/PEG blend exhibited intermediate values of elastic modulus (G') and complex viscosity (η*) with excellent flexibility. Thermal analysis of different clay loading blends indicated that the melting temperature (T(m)) and glass transition temperature (T(g)) remained unaffected irrespective of clay concentration due to immobilization of polymer chain in the clay nanocomposite. PEG incorporation reduced the T(g) and the T(m) of the blends (PLA/PEG and PLA/PEG/clay) significantly, however, crystallinity increased in the similar condition. The transmission electron microscopy (TEM) image of nanocomposite films indicated good compatibility between PLA and PEG, whereas clay was not thoroughly distributed in the PLA matrix and remained as clusters. The percent crystallinity obtained by X-ray was significantly higher than that of differential scanning calorimeter (DSC) data for PLA.     

双组分聚氨酯涂层剂防水透湿性能的研究

以(PEA、PTMG、PPG)／PEG混合多元醇作为聚醚二醇组分与MDI进行预聚，然后用1，4-丁二醇扩链合成具有防水、透湿性的聚氨酯涂层剂，研究了PEG分子质量、软段w(PEG)、w(硬段)以及软段单体结构对涂层剂防水透湿性能的影响，实验表明，涂层织物的防水透湿性能与涂层剂的w(亲水链段)和交联度有关．当PEG分子质量和软段的w(PEG)增大时，涂层织物的透湿量也随之增大，耐静水压值则减小；当w(硬段)增大时，涂层织物的透湿量则减小，耐静水压值随之增大；当软段单体从PEA到PTMG到PPG亲水性逐级增大日寸，涂层织物的透湿量也随之增大，耐静水压值则减小，     

Improved immobilization yields by addition of protecting agents in glutaraldehyde-induced immobilization of protease

The effects of peptides and polyethylene glycol (PEG) on the immobilization of protease using glutaraldehyde-activated Lewatit R258-K resin were investigated. When soy peptide was added at 0.1 g/l, the activity recovery and effectiveness factor increased by 20% and 38%, respectively. When PEG4000 (0.5 g/l) was used as a protecting agent, the activity recovery and effectiveness factor were improved by 35% and 60%, respectively, leading to an increased specific activity of the immobilized enzyme. The addition of PEG4000 is suggested to improve the cost-effectiveness for the production of immobilized enzymes.     

制备条件对玉米醇溶蛋白膜机械性能的影响

以玉米醇溶蛋白为原料制备蛋白膜时,研究了乙醇浓度、蛋白质浓度等制备条件对蛋白膜机械性能的影响。在单因素实验基础上,以蛋白质浓度、甘油添加量、聚乙二醇400添加量、半胱氨酸添加量4个因素为变量进行响应面优化,结果表明:当乙醇体积分数为75%、水浴成膜温度70℃、蛋白质浓度0.103 4g/ml、甘油质量分数30%、聚乙二醇400质量分数24%、半胱氨酸质量分数0.80%时,蛋白膜的拉伸强度为7.5MPa,断裂延伸率为202.7%。     

聚乙二醇/盐双水相萃取L-苯丙氨酸的研究

研究了聚乙二醇/盐双水相体系的成相行为及L-苯丙氨酸在双水相中的分配规律,其中包括聚乙二醇的分子量、聚乙二醇质量分数、盐的种类及加入量、L-苯丙氨酸初始浓度和pH对萃取分离的影响。当聚乙二醇1000的质量分数为27%,磷酸氢二钾的质量浓度为0.15g/mL,L-苯丙氨酸的质量浓度为10g/L,体系的pH为8.5时,L-苯丙氨酸的萃取率最高为99.5%,分配系数最大为186.5。     

THE EFFECTS of PLASTICIZERS ON CRYSTALLINITY, PERMEABILITY, and MECHANICAL PROPERTIES of METHYLCELLULOSE FILMS

The effects of plasticizers (polyethylene glycols [PEG] 400, 1,450, 8,000 and 20,000, glycerol [G] and propylene glycol [PG]), 30% dry basis, on the physical properties of methylcellulose (MC) films were investigated. With the exception of PG, plasticizers with low molecular weights (G and PEG 400) caused the largest increase in the d₁₀₁ spacing of the crystal lattice. All plasticizers significantly (α= 0.05) increased oxygen (O₂P) and water vapor permeabilities (WVP) of the films as compared to that of unplasticized MC, with PEG 400 having the greatest effect on O₂P and G having the greatest effect on WVP. With the exception of PG, all plasticizers decreased the tensile strength of MC films, with PEG 400 causing the largest decrease. With the exception of PG and PEG 400, all plasticizers increased percent elongation values of MC films, with PEG 1,450 having the greatest effect. Glycerol and PEG were the most effective plasticizers for MC. the higher molecular weight plasticizers do provide some plasticizing properties and may be more suitable for applications that require a lower permeability to water vapor than can be achieved with glycerol.