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1.
牛磺胆酸钠的制备及与胆酸的药效对比   总被引:3,自引:2,他引:3  
以胆酸和牛磺酸为基本原料制备了牛磺胆酸钠 (TCANa) ,收率超过 5 9% ,w(TCANa) >92 % ,其IR和1HNMR与结构相符。并将牛磺胆酸钠与胆酸钠进行镇咳、祛痰和平喘对比实验。药理实验结果为 :牛磺胆酸钠和胆酸钠的镇咳作用减咳率分别为 (2 8 6± 6 7) %和 (18 2±6 8) % ;祛痰作用酚红排泌量分别为 (1 4 82± 0 4 0 1) μg/mL和 (0 95 9± 0 312 ) μg/mL ;平喘作用解痉率分别为 (71 2± 2 3 1) %和 (71 2± 2 3 1) % ,与生理盐水间存在着显著性差异 ,牛磺胆酸钠与胆酸钠间也存在显著性差异。药理实验表明牛磺胆酸钠具明显的镇咳、祛痰和平喘作用 ,其作用强于胆酸  相似文献   

2.
采用溶液流延法以豌豆淀粉(PS)和聚乳酸(PLA)为原料制备了豌豆淀粉/聚乳酸(PS/PLA)双层薄膜。通过对双层薄膜的吸水性、溶解性、水蒸气透过性、拉伸性能、表面形貌等进行测试,研究了薄膜的力学性能、疏水性能以及水蒸气阻隔性能。结果表明:随着双层膜中聚乳酸层的比例增加,双层薄膜的吸水性、溶解性和水蒸气透过性逐渐降低,拉伸强度和拉伸模量逐渐增加,断裂伸长率逐渐下降,表明水蒸气阻隔效果明显,增加了膜的韧性,降低了膜的强度。当PLA和PS的质量比为50:50时,PS/PLA双层膜的拉伸强度为(13.47±0.75)MPa,拉伸模量为(0.848±0.002)GPa;断裂伸长率为(16.11±0.16)%,水蒸气透过系数为0.27×10-10 g·cm/(cm2·s·Pa)。  相似文献   

3.
70%啶虫脒水分散性粒剂的配方研究   总被引:2,自引:0,他引:2  
张荣胜 《现代农药》2008,7(6):22-24
以97.9%啶虫脒为原药,氯化铵为崩解剂,润湿剂M为润湿剂,萘磺酸甲醛缩合物加ZX–D9为分散剂,膨润土为填料,对70%啶虫脒水分散性粒剂的配方进行研究,并确定了最佳配方。实验结果表明,产品悬浮率达到90%以上,崩解时间小于1min,热贮[(54±2)℃,2周]分解率小于2.5%,产品各项指标符合水分散粒剂的要求。  相似文献   

4.
聚乳酸(PLA)和天丝(Tencel)混纺纱的性能除了受到纤维本身和纱线捻度的影响,也跟纱线混纺比有很大关系。实验以不同混纺比的PLA/Tencel混纺纱为基本素材,进行力学性能测试,通过实验数据的分析,探索纱线力学性能随混纺比变化的规律。结果表明,标准状态下,混纺纱的强度随PLA质量分数的减少先减小后增大,混纺比在质量分数PLA60%/Tencel40%时,纱线强度降到最低点;混纺纱的湿强度随混纺比的变化趋势与干强度基本一致,临界混纺比相差也不大;混纺纱弹性回复率随PLA质量分数的减少,先增大后减小,PLA质量分数为70%时,纱线弹性回复率最大,纯Tencel纱线弹性回复率最小。  相似文献   

5.
TCDCANa的合成及抗菌抗炎作用研究   总被引:3,自引:0,他引:3  
以鹅去氧胆酸(CDCA)和牛磺酸为基本原料合成了牛磺鹅去氧胆酸钠(TCDCANa),以萃取和重结晶法提纯,收率63.4%,w(TCDCANa)≥92%,以TLC和IR法确定了其结构。并将牛磺鹅去氧胆酸钠与鹅去氧胆酸钠(CDCANa)进行了抗菌、抗炎和镇咳对比实验。药效实验结果为:TCDCANa和CDCANa均具有抗革兰阳性菌作用(抑菌环直径分别为2.46±0.08cm和1.91±0.13cm),抗炎作用抑制率分别为(79.1±25.4)%和(71.2±23.1)%,镇咳作用减咳率分别为(29.1±5.6)%和(18.2±6.8)%,牛磺鹅去氧胆酸钠与鹅去氧胆酸钠间存在显著性差异。药效实验表明,TCDCANa具明显的镇咳、平喘和抗菌作用,其作用强于CDCANa。  相似文献   

6.
《合成纤维》2021,50(6):49-52
羊毛、桑蚕丝、黏纤和聚酯纤维四组分混纺产品定量分析难度较大,采用了36%盐酸法,与原有的75%硫酸法和甲酸/氯化锌法作对比。结果表明:用36%盐酸法测定羊毛、桑蚕丝、黏纤和聚酯纤维四组分混纺产品,试验的误差最小、精确度最高,因此,可用36%盐酸法对羊毛、桑蚕丝、黏纤和聚酯纤维四组分混纺产品进行定量化学分析。  相似文献   

7.
过磷酸钙中有效磷的直接提取   总被引:2,自引:0,他引:2  
研究了用中性柠檬酸铵一次性地提取过磷酸钙样品中有效磷 ,较现行化工行业标准节约时间 1~ 1.5h ,操作简便 ,提取完全 ,本方法测试结果与标准法测试结果相差小于± 0 .15%。  相似文献   

8.
以500 mL鸡胆汁为基本原料,采用沉淀、过滤、减压蒸馏、真空干燥、抽提、重结晶法,制得了7.2 g结合型的牛磺鹅去氧胆酸钠(TCDCANa),以TLC及IR法确定其结构。并将其与鹅去氧胆酸钠(CDCANa)进行镇咳、平喘和祛痰作用对比实验。药理实验结果为:TCDCANa和CDCANa的镇咳作用减咳率分别为(29.1±5.6)%和(18.2±6.8)%;平喘作用解痉率分别为(79.9±22.8)%和(73.3±22.7)%,祛痰作用酚红排泌量分别为(1.601±0.391)μg/mL和(1.029±0.308)μg/mL,TCDCANa与CDCANa间存在显著性差异(P<0.01)。药理实验结果表明,TCDCANa具有明显的镇咳、平喘、祛痰和抗炎作用,其作用强于CDCANa。  相似文献   

9.
目的构建针对人高迁移率族蛋白A1(HMGA1)基因的RNA干扰真核表达载体,为研究HMGA1基因在肿瘤细胞中的作用奠定实验基础。方法设计合成特异性针对人HMGA1基因的寡核苷酸序列,梯度退火后,与pU6mRFP载体连接,构建重组载体,转染人肝癌细胞SMMC-7721。通过激光共聚焦显微镜观察红色荧光,估测转染效率,RT-PCR法检测转染细胞HMGA1mRNA水平,流式细胞仪检测细胞凋亡和细胞周期。结果DNA测序证实,成功构建了特异性HMGA1siRNA真核表达载体,转染后72h,转染效率为40%左右。所构建的载体能够特异性沉默转染细胞HMGA1基因的表达。转染细胞HMGA1基因沉默后,细胞凋亡率(27·86%±2·44%)明显高于空载体对照组和SMMC-7721对照组(分别为2·82%±2·39%和2·04%±0·70%),G0-G1期细胞百分数(77·73%±1·78%)明显高于空载体对照组和SMMC-7721对照组(分别为42·19%±3·28%和39·23%±3·63%),G2-S期细胞百分数(22·27%±1·78%)明显低于空载体对照组和SMMC-7721对照组(分别为57·81%±3·28%和60·77%±3·63%)。结论成功构建了HMGA1的RNA干扰真核表达载体。  相似文献   

10.
25%苯醚甲环唑水悬浮剂的研制   总被引:3,自引:2,他引:1  
李波 《现代农药》2009,8(1):30-33
苯醚甲环唑是一种广谱内吸型杀菌剂,对多种作物的病害有较好防治效果。介绍了农药悬浮剂的实验理论依据,并采用优化组合法对25%苯醚甲环唑水悬浮剂的表面活性剂进行了筛选。试验结果表明,该产品悬浮率90%以上,热贮(54℃±2℃,14d)分解率小于5%,产品各项指标符合悬浮剂的要求。  相似文献   

11.
The thermal degradation behavior of the blend based on polylactide (PLA) and poly(1,2‐propanediol 2‐carboxyethyl phenyl phosphinate) (PCPP) was investigated by the thermogravimetric analysis (TGA). Thermal degradation activation energies (Ea) of neat PLA and PLA/15% PCPP blend were calculated via the Flynn–Wall–Ozawa method. The Ea of the blends increased with the addition of PCPP increasing when the conversion was higher than 10%. In addition, the appropriate conversion models for the thermal degradation process of PLA and PLA/15% PCPP were studied via the Criado method. At the same time, the main gaseous decomposition products of PLA and its blend were identified by TGA/infrared spectrometry (TGA–FTIR) analysis. And it revealed that the PCPP improved the flame‐retardant property of PLA via altering the release of the flammable gas and nonflammable gas. Moreover, the PCPP improved the flame‐retardant property of PLA by inhibiting exothermic oxidation reactions in the combustion, which was further proved by pyrolysis–gas chromatography–mass spectrometry analysis. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40480.  相似文献   

12.
采用两种不同分子量的聚(ε-己内酯)(PCL)(粘均分子量60 000和3 000)与聚乳酸(PLA)在175℃下共混10 min制备PLA/PCL共混物。通过动态流变、扫描电子显微镜(SEM)和力学性能等研究了PLA/PCL共混物的结构和性能。动态流变显示,在PCL低含量(质量分数小于15%)时,PCL与PLA是相容的,质量分数为15%时PCL与PLA表现出明显的相分离行为。SEM显示,随着PCL含量的增加,PCL相的尺寸变大;低分子量PCL(L-PCL)的相尺寸明显大于高分子量PCL(H-PCL),而且相形态不是规则的球状。随着PCL含量的增加,共混物的拉伸强度下降,而断裂伸长率增加。当H-PCL质量分数为8.3%时,PLA/H-PCL共混物的断裂伸长率为137.32%。当H-PCL质量分数为15%时,其断裂伸长率高达232.76%。在添加相同含量PCL时,PLA/H-PCL共混物的拉伸强度高于PLA/L-PCL;而PCL质量分数8%时,共混物的断裂伸长率相差不多,当PCL质量分数大于8%时,PLA/H-PCL共混物的断裂伸长率明显比PLA/L-PCL共混物的高。  相似文献   

13.
Isothermal crystallization kinetics and spherulite morphologies of partially immiscible blends of poly(lactic acid) (PLA) and ethylene acrylate copolymer (EAC) were investigated by differential scanning calorimetry (DSC) and polarized optical microscopy. The DSC data obtained was analyzed using the Avrami equation. Crystallization kinetics of PLA from the melt was strongly influenced by the blend composition and the crystallization temperature. At a given crystallization temperature, the overall crystallization rate value was greater in the blends than in PLA suggesting that the presence of EAC enhanced crystallization of PLA. Polarized optical micrographs showed that the crystallization of PLA initially took place at the PLA/EAC interface. At high EAC content (>1 wt %), EAC domains acted as hindrance to crystallization reducing the overall crystallization rate of PLA in the blends. Based on the DSC analysis, the crystallization rate was maximum when PLA blend with 1 wt % EAC was isothermally crystallized at 103 °C. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45487.  相似文献   

14.
In this article, the spherulitic growth rate of neat and plasticized poly(lactic acid) (PLA) with triphenyl phosphate (TPP) was measured and analyzed in the temperature range of 104–142°C by polarizing optical microscopy. Neat PLA had the maximum value of 0.28 μm/s at 132°C, whereas plasticized PLA had higher value than that of neat PLA, but the temperature corresponding to the maximum value was shifted toward lower one with increasing TPP content. The isothermal crystallization kinetics of neat and plasticized PLA was also analyzed by differential scanning calorimetry and described by the Avrami equation. The results showed for neat PLA and its blends with various TPP contents, the average value of Avrami exponents n were close to around 2.5 at two crystallization temperatures of 113 and 128°C, the crystallization rate constant k was decreased, and the half‐life crystallization time t1/2 was increased with TPP content. For neat PLA and its blend with 15 wt % TPP content, the average value of n was 2.0 and 2.3, respectively, the value of k was decreased, and the value of t1/2 was increased with crystallization temperature (Tc). Further investigation into crystallization activation energy ΔEa of neat PLA and its blend with 15 wt % TPP showed that ΔEa of plasticized PLA was increased compared to neat PLA. It was verified by wide‐angle X‐ray diffraction that neat PLA and its blends containing various TPP contents crystallized isothermally in the temperature range of 113–128°C all form the α‐form crystal. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

15.
To explore a potential method for improving the toughness of a polylactide (PLA), we used a thermoplastic polyurethane (TPU) elastomer with a high strength and toughness and biocompatibility to prepare PLA/TPU blends suitable for a wide range of applications of PLA as general‐purpose plastics. The structure and properties of the PLA/TPU blends were studied in terms of the mechanical and morphological properties. The results indicate that an obvious yield and neck formation was observed for the PLA/TPU blends; this indicated the transition of PLA from brittle fracture to ductile fracture. The elongation at break and notched impact strength for the PLA/20 wt %TPU blend reached 350% and 25 KJ/m2, respectively, without an obvious drop in the tensile strength. The blends were partially miscible systems because of the hydrogen bonding between the molecules of PLA and TPU. Spherical particles of TPU dispersed homogeneously in the PLA matrix, and the fracture surface presented much roughness. With increasing TPU content, the blends exhibited increasing tough failure. The J‐integral value of the PLA/TPU blend was much higher than that of the neat PLA; this indicated that the toughened blends had increasing crack initiation resistance and crack propagation resistance. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011  相似文献   

16.
Natural rubber (NR) was melt blended with polylactic acid (PLA) at various ratios using an internal mixer. The impact strength and elongation at break of PLA/NR blend dramatically increased with increasing NR content up to 10% (w/w). Glycidyl methacrylate-grafted natural rubber (NR-g-GMA) was used as a compatibilizer for PLA/NR blend. The effects of content and %grafting of NR-g-GMA on mechanical properties of PLA/NR blend were studied. The experimental result showed that the addition of NR-g-GMA in PLA/NR blend significantly improved impact strength and elongation at break of PLA/NR blend when compared with that of neat PLA and PLA/NR blend without NR-g-GMA. The impact strength and elongation at break of PLA/NR blend increased with increasing NR-g-GMA content up to 1% (w/w). Moreover, with increasing % grafting of NR-g-GMA in PLA/NR blend up to 4.35, the impact strength and elongation at break of the blend increased. Morphological and thermal property of PLA, PLA/NR, and PLA/NR/NR-g-GMA were elucidated as well. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

17.
The present paper aims to obtain a sustainable nanocomposite by using bio-based polyamide 11 and biodegradable poly (lactic acid) blend as matrix and graphene nanoplatelets (GNP) as nanofiller. GNP was incorporated in the PA11/PLA blend matrix in the ratio of 0.5-1-3-5-10 wt% through the twin-screw extruder. The crystallinity of PA11 in the blend, which was 12.9%, increased with the inclusion of GNP, and the highest crystallinity value was observed at 20% for the 1GNP sample. The crystallinity of PLA in the blend, which was 2.3%, increased to 4.6% with 5 wt% GNP addition. The inclusion of GNP to PA11/PLA improved the thermal degradation temperatures and increase the char residue. Also, increments were observed for storage modulus, loss modulus, and glass transition temperature of the matrix with the inclusion of GNP. The addition of GNP caused the tensile strength of the matrix to increase first and then decrease at higher amounts due to the agglomerations. 0.5–1 wt% GNP increased tensile strength by 10% and 5%, respectively. Increasing the amount of GNP to 10 wt% led to a sharp decrease in tensile strength by 24%. Overall, GNP is a suitable nanofiller to enhance the thermal and mechanical features of the PA11/PLA blend.  相似文献   

18.
The objectives of this study are to investigate the effect of silica nanoparticles on the morphology and rheological behavior of immiscible linear low‐density polyethylene/poly(lactic acid) (LLDPE/PLA) blends. Melt blending method is applied to prepare the blends and their nanocomposites. Scanning electron microscope and parallel plate rheometer were used to investigate morphology and rheological behavior of the blend nanocomposites. Scanning electron microscope results demonstrated a significant change in morphology behavior by incorporation of silica nanoparticles. A significant reduction in the PLA droplet for LLDPE/PLA (75/25) with 8 wt % silica was observed. The rheological studies illustrated that for all samples storage modulus and complex viscosity of blend nanocomposites are higher than neat blends. Finally, melt rigidity of blend nanocomposites was estimated by measurement of rheological properties using a rotational rheometer through small amplitude oscillatory shear experiments. As a result, through the shear data, a high value quantity as a criteria for melt rigidity is obtained for the LLDPE/PLA (75/25) with 8 wt % silica in comparing to the other samples. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45526.  相似文献   

19.
The effects of the extrusion rate on the morphological changes of poly(lactic acid) (PLA)/poly(vinyl alcohol) (PVA) blend through a capillary die were investigated. In this study, the extrusion rate or mass flow rate is altered from 0.5 g min?1 to 2 g min?1 with an increment of 0.5 g min?1. The PLA/PVA blend with a composition of 30/70 (wt %) exhibits a particle matrix morphology with dispersed PLA droplets within the PVA matrix. It is found that, the spherical or ellipsoidal dispersed PLA droplets are elongated and coalesced into rod‐like or longer ellipsoidal droplets when they pass through the capillary die. When the extrusion rate increases, the coalescence between the large PLA droplets occurs more intense. However, the changes of the extrusion rate have no strong effect on the coalescence of small droplets having diameter less than about 150 nm. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44257.  相似文献   

20.
T. Cornelissen  G. Reggers  R. Carleer 《Fuel》2008,87(7):1031-1041
High amounts of water present in bio-oil are one of the major drawbacks for its utilisation as a fuel. One technology that shows the potential to satisfy the demand for bio-oil with a reduced water content is the flash co-pyrolysis of biomass with polylactic acid, PLA. The influence of PLA on the pyrolysis of willow is investigated with a semi-continuous home-built pyrolysis reactor. Flash co-pyrolysis of willow/PLA blends (10:1, 3:1, 1:1 and 1:2) show synergetic interaction. A higher bio-oil yield and a lower water content as a function of the willow/PLA ratios are obtained. Among the tested blends, the 1:2 willow/PLA blend shows the most pronounced synergy: a reduction in the production of pyrolytic water of almost 28%, accompanied by an increase of more than 37% in the production of water-free bio-oil. Additionally, PLA shows to have a positive influence on the energetic value of the bio-oil produced and on the resulting energy recuperation.  相似文献   

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