双醛淀粉改性聚醋酸乙烯酯乳液胶粘剂的制备

研究了双醛淀粉作为含醛物料与白乳胶中聚乙烯醇进行缩合反应,制备了环保型聚醋酸乙烯酯乳液胶粘剂。讨论了双醛淀粉的改性机理,并对其影响因素进行了探讨。     

双醛淀粉流变性的研究

双醛淀粉毒性低、化学反应活性高,广泛应用于各种工业,是一种很重要的化工原料,而双醛淀粉的流变性会对双醛淀粉的应用产生重大的影响.本文研究了不同pH下制备双醛淀粉的流变性,结果表明:溶液呈胀流型,提高剪切速率,粘度略有增加,pH3.5下制备双醛淀粉的粘度比pH7下制备双醛淀粉的粘度低.     

环保型DAS-PVA建筑胶粘剂问世

广西贺州学院生化系以聚乙烯醇（PVA）和双醛淀粉（DAS）、高碘酸钠、翻酸等作原料,在一定温度及酸性条件下,制备成功环保型DAS—PVA建筑胶粘剂。该剂外观呈无色或浅红色,游离甲醛含量低（0．001％）。粘接强度达65MPa,固含量20％。该剂耐水性及防腐性能佳,化学稳定性高,生产成本低,产品适合于建筑材料粘接加工作业要求。将双醛淀粉应用于制造建筑胶钻剂是一个新的尝试,具有一定现实意义。     

正交法优化拟均相体系制备双醛淀粉的工艺

以木薯淀粉为原料、高碘酸钠为氧化剂,采用L9(43)正交设计,研究了拟均相体系制备双醛淀粉的最佳工艺条件。结果表明,在温度为35℃、高碘酸钠浓度为0.6 mol.L-1、反应pH值为4、反应时间为2.5 h的最佳条件下,双醛淀粉的双醛含量达到92.5%。     

聚乙烯醇缩丁烯醛胶粘剂的研究进展

综述了聚乙烯醇缩丁烯醛胶的制备原理和制备方法,并主要讨论了聚乙烯醇缩丁烯醛在国内外的应用进展情况。     

聚乙烯醇缩丁烯醛胶的研究进展

综述了聚乙烯醇缩丁烯醛胶的制备原理和制备方法,并讨论了聚乙烯醇缩丁烯醛胶在国内外的应用进展情况.     

光促催化氧化玉米淀粉制备双醛淀粉的研究

用TiO2光催化剂催化玉米淀粉制备双醛淀粉,最佳工艺条件为:反应温度20℃,反应时间3 h,催化剂加入量为淀粉的10%,通入空气量为13 mL/min。实验结果表明,氧化度值为38%,工艺过程简单,污染小,操作费用低,是一种具有开发潜力的双醛淀粉制备新型工艺。     

环保型聚乙烯醇缩丁烯醛胶的制备研究

探讨了聚乙烯醇(PVA)、盐酸、丁烯醛以及反应温度对聚乙烯醇缩丁烯醛水溶液粘度及强度的影响;并探讨了低残余醛水溶液制备的两类工艺方法,从而获得环保型聚乙烯醇缩丁烯醛胶。     

友刊链接

新型脲—双醛淀粉粘合剂的制备王新波,吴佑实(山东大学材料科学与工程学院) //山东化工2 0 0 3- 0 4 - 0 1将淀粉改性制得性能优异的双醛淀粉,代替甲醛与尿素缩合反应,合成出全新无毒的脲—双醛淀粉胶粘剂。讨论了双醛淀粉与尿素的反应机理,并对2者反应的影响因素进行概括分析。UHMWPE纤维用氯丁橡胶粘合剂的制备及应用研究王结良,何洋,梁国正(西北工业大学化工系) //特种橡胶制品2 0 0 3- 0 4 - 0 9研究了丙烯酸丁酯(BA)和氯丁橡胶(CR)粘合剂的接枝共聚合反应。用正交设计方法探讨了引发剂用量、丙烯酸丁酯用量、温度和时间对产物性能…     

淀粉/丙烯酸/PVA互穿网络高吸水性树脂的合成

以淀粉、丙烯酸(AA)和聚乙烯醇( PVA)为原料,N,N-亚甲基双丙烯酰胺为交联剂,采用水溶液聚合法制备了淀粉/丙烯酸/聚乙烯醇互穿网络高吸水性树脂;探讨了淀粉、PVA、引发剂、交联剂用量及丙烯酸中和度对产物吸水倍率的影响;用红外光谱对产物进行了表征.结果表明,所制备的互穿网络高吸水性树脂的吸蒸馏水和生理盐水能力最高...     

淀粉酯的合成、性质及应用

由于淀粉的可再生性和可应用性现已受到人们的广泛关注。通过酯化过程对淀粉改性,使淀粉的性质发生改变,扩大了淀粉的应用领域。文章对琥珀酸淀粉酯、醋酸淀粉酯、柠檬酸淀粉酯、长链脂肪酸淀粉酯、磷酸淀粉酯、硫酸淀粉酯的合成、性质及应用进行了综述,并对其发展前景进行展望。     

The chemical nature of algal (Chlorella) starch and its estimation in whole cells

The estimation of the starch content of chlorella cells was based on the sonication of whole cells in 2M NaOH followed by heating to solubilise the starch. The starch content of the solution was estimated by measurement of the glucose equivalents formed by acid hydrolysis. The starch content of the neutral solution was estimated by measuring light absorbance of its blue complex with iodine. The chlorella starch was purified from cells which had been disrupted in a French press, and the starch was solubilised by boiling with water. The starch was deproteinised, desalted and finally precipitated with ethanol before drying. This purification procedure avoided alkali extraction which degrades the starch. β-Amylase digestion of the purified starch was found to convert 67% of it to maltose. The purified starch gave a bright blue complex with iodine with peak absorbance at 590 nm.     

淀粉/天然橡胶复合材料的研究

将淀粉进行糊化改性,将改性淀粉在乳液状态下与天然胶乳共混,制备淀粉/天然橡胶复合材料。用X-射线衍射（XRD）、差示扫描量热仪（DSC）和扫描电镜（SEM）表征复合材料的结构,并测定了其力学性能。研究结果表明：淀粉经糊化后,复合材料中淀粉粒子的结晶结构消失,粒子在天然橡胶中分散均匀,粒径明显减小。随着淀粉含量的增加,复合材料的硬度、定伸应力、拉伸强度和撕裂强度随之提高,且当其质量分数在20%时,复合材料的综合力学性能最佳。     

An In-depth Analysis of the Mechanical,Electrical, and Drug Release Properties of Gelatin–Starch Phase-Separated Hydrogels

Gelatin–starch-based phase-separated hydrogels were prepared in this study. Corn starch, soluble starch, and hydrated starch were used as the representative starches for the preparation of the hydrogels. Bright field microscopy suggested the formation of phase-separated hydrogels. An increase in the hydrophilic nature of the starch molecules resulted in decrease in the agglomeration of the starch particles within the gelatin matrices. Fourier transform infrared study confirmed the presence of starch particles within the hydrogels. X-ray diffraction studies suggested that the higher degree of crystallinity of corn starch and soluble starch was responsible for the comparative hydrophobic nature of these starch particles. Hydrated starch was found to be amorphous in nature and can be explained by the destruction of the intramolecular associative forces. Stress relaxation and creep recovery studies indicated predominant elastic nature of the hydrogels. Hydrated starch-containing hydrogels were firmer than corn starch and soluble starch because of the better miscibility of the hydrated starch particles within the gelatin matrices. The bulk resistance of the starch-containing hydrogels was higher. This was because of the capability of the starch particles to behave as dielectric medium. Incorporation of starch particles within the gelatin matrix was found to increase the polymer relaxation-mediated drug diffusion. Metronidazole-loaded hydrogels were found to have good antimicrobial activity.     

淀粉的热塑性研究

通过在淀粉中加入增塑剂，制备热塑淀粉，研究了3种不同淀粉－玉米淀粉，木薯淀粉和可溶性淀粉的增塑性情况，研究了甘油、乙二醇、山梨醇、聚乙烯醇4种塑剂的增塑效果，不同的淀粉品种及不同增塑剂的产品性能有所不同。在显微镜下观察到，淀粉经塑化后，次价键断裂，晶区被破坏，使淀粉具备了热塑性，可以加工成薄膜。     

Preparation and properties of biodegradable poly(butylene succinate)/starch blends

The vital differences between the use of untreated starch and gelatinized starch in blends with poly(butylene succinate) (Bionolle) were thoroughly examined in this study. The melting temperature decreased slightly with increasing dosages of untreated and gelatinized starch. The added starch perhaps tended to disrupt the intermolecular hydrogen bonding within the Bionolle matrix. On the other hand, a large increase in the crystallinity was seen with the addition of starch. Starch appeared to play a nucleating role in the blends. The trend of the glass‐transition temperature decreasing with the starch level was similar to the trend of the melting temperature. For the same starch content, the glass‐transition temperature showed some variations. For blends containing a certain amount of gelatinized starch, the thermal stability remained to a certain degree but continued to decrease. This was ascribed to the relatively low heat stability of starch. As for the mechanical properties, a significant increase in the tensile strength (up to 2 times) was observed when untreated starch was replaced with gelatinized starch in the blends. Similarly, the tear strength increased up to 1.5 times if gelatinized starch was employed. Apparently, the gelatinization of starch was efficiently achieved for promoting its compatibility with Bionolle. In all cases, the mechanical properties of Bionolle blended with gelatinized starch were better than those of Bionolle blended with untreated starch. A morphological investigation provided evidence in support of these findings. This relatively low‐cost gelatinization approach provides an alternative to a high‐cost compatibilizer approach for improving the performance of biodegradable blends. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 257–264, 2005     

机械活化对木薯淀粉醋酸酯化反应的强化作用

采用搅拌球磨机对木薯淀粉进行机械活化,以不同活化时间的木薯淀粉为原料,以醋酸酐为酯化试剂、甲磺酸为催化剂制备淀粉醋酸酯,并以取代度为评价指标,分别研究了机械活化时间、反应时间、反应温度、催化剂用量及醋酸酐用量对木薯淀粉醋酸酯化反应的影响. 结果表明,机械活化对木薯淀粉酯化反应有显著的强化作用,活化时间越长,取代度越高. 主要原因是机械活化使木薯淀粉紧密的颗粒表面和结晶结构受到破坏,降低了结晶度,酯化试剂更容易渗透到颗粒内部使淀粉醋酸酯化. 其他因素对淀粉酯化反应的影响规律受活化时间的制约,活化时间越长,酯化反应对反应温度、催化剂及醋酸酐浓度的依赖性越低. 并利用红外光谱对木薯淀粉、活化淀粉及高取代度淀粉醋酸酯的结构进行了表征.     

Morphology,thermomechanical properties,and biodegradability of low density polyethylene/starch blends

The biodegradability of low density polyethylene (LDPE)/starch and LDPE/starch/starch acetate (STAc) blends was tested and observed to be dependent on STAc content. The binary and ternary blends containing up to a maximum concentration of 30% starch were examined for their thermal, mechanical, and morphological properties. The blends with no STAc or 2.5% STAc show almost no adherence of two phases. With 10% STAc, dispersion of starch was observed to increase with some adherence to LDPE. Tensile strength, elongation at break, and Izod impact strength of the blends decreased with increased starch content. However, incorporation of STAc along with starch improved all these properties, particularly elongation at break and toughness. The melt flow index was also improved on partial substitution of starch by STAc. Maximum biodegradability was observed for the blends containing 30% (starch + STAc). Cell growth was observed to increase with increasing concentration of (starch + STAc) in the blends. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2791–2802, 1999     

Effect of amphiphilic phosphate/octenylsuccinate starch on enhancing adhesion to hydrophobic polyester fibers in sizing

Amphiphilic starch at different degree of substitution (DS) was prepared by phosphorylation and octenylsuccinylation of acid-thinned starch with sodium tripolyphosphate and 2-octenylsuccinic anhydride, respectively for improving the adhesion of starch to polyester fibers. Various assessment of starch such as ¹H NMR and FTIR analysis, apparent viscosity, starch clarity, adhesion to polyester fiber, desizing efficiency and biodegradability were conducted. The ¹H NMR and FTIR spectroscopy revealed that octenylsuccinate and phosphate substituents have been attached to the molecular chain of starch. Also, the apparent viscosity, paste clarity, desizing efficiency and biodegradability of the amphiphilic starch increased as the DS of phosphate increased. It was observed that the amphiphilic starch was an effective method for stronger adhesion unto polyester fibers but reduced at the highest DS of phosphate due to excessive hydrophilicity. As compared to acid-thinned starch, the stronger adhesion of the amphiphilic starch was attributed to the steric hindrance caused by the two substituents on starch and the good dispersibility impacted by the phosphate substituents on starch. Conclusively, the strongest adhesion on polyester fibers, good paste clarity, good desizing efficiency and enhanced biodegradability of starch were attained at phosphate and octenylsuccinate DS ratio of 0.031/0.014.     

热重法测定淀粉基塑料中淀粉含量的方法研究

采用热重（TG）法测定淀粉基塑料中的淀粉含量。首先,确定淀粉和淀粉基塑料在TG曲线中的特征温度及该温度所对应的质量损失率,结果表明,淀粉与树脂的热失重特征温度存在明显差异,淀粉基塑料中各组分的失重相对独立,且失重过程与各组分单独失重时相同,因此可通过纯淀粉的失重率采用比例法计算淀粉基塑料中的淀粉含量,当淀粉含量超过10 %时,比例法计算的结果的相对误差小于10 %。