烯基琥珀酸酐疏水化淀粉的性能及其表面施胶应用研究

为制备一种环境友好型表面施胶剂,采用烯基琥珀酸酐(ASA)对淀粉进行疏水改性,使用红外光谱(FT-IR)、X射线衍射(XRD)、扫描电镜(SEM)和表面张力仪等测试手段对其性能进行了表征,并将烯基琥珀酸酐疏水化改性淀粉作为纸张表面施胶剂进行应用研究。结果表明,在淀粉分子上成功引入疏水性长链,淀粉颗粒形貌发生了变化,烯基琥珀酸酐疏水化淀粉施胶浓度为5%时,其施胶度可达206s,动态接触角达120°以上。     

SiO2气凝胶的疏水性改性研究

采用三甲基氯硅烷（TMCS）对硅溶胶制备的湿SiO2气凝胶进行表面疏水改性处理,研究了TMCS与孔洞中水的摩尔比对气凝胶的疏水改性作用与性能,用红外光谱法检测了疏水性改性的SiO2气凝胶,发现气凝胶表面的-OH被-OR基团取代,以此构建SiO2气凝胶的疏水性改性机理及模型,试验结果表明,TMCS与孔洞中水的摩尔比控制在0．35左右时可获得不开裂、完好的、具有憎水性特征的二氧化硅气凝胶。     

改性淀粉微球对废水中Cu2+ 、Ni2+吸附性能的研究

改性淀粉表面和内部聚集了大量的活性基团,多孔的特殊结构使其在废水处理、吸附污染物等方面具有较大的应用潜力。以玉米淀粉为原料,通过改性处理得到接枝丙烯酸甲酯的改性淀粉,以改性淀粉为原料在酶的作用下制备了改性淀粉微球。利用扫描电子显微镜对玉米淀粉、改性淀粉、改性淀粉微球进行了分析,研究了改性淀粉微球对废水中重金属的吸附性能。结果表明:改性淀粉微球在酶溶液体积为0.06mL时吸附作用最为明显,对重金属离子有良好的吸附作用,对Cu~(2+)和Ni~(2+)的最高去除率达到74.53%和67.57%。     

玉米淀粉与铈盐引发丙烯酸甲酯及丙烯酸盐接枝共聚物

玉米淀粉与铈盐引发丙烯酸甲酯及丙烯酸盐接枝共聚物，其主要原料为玉米淀粉、铈盐、丙烯酸甲酯、丙烯酸盐，将淀粉与丙烯酸甲酯经高铈盐引发接技共聚物，它既具有淀粉浆料的特点，又具有合成浆料的特点，它对疏水性纤维的粘着性、浆膜弹性、成膜性、伸度、浆液黏度稳定性、流动性均有很大程度的提高，可取代PVA，降低生产成本，减少环境污染。     

聚偏氟乙烯膜的亲水化改性研究进展

强疏水性聚偏氟乙烯(PVDF)膜的亲水化改性是当前分离膜研究的热点之一.从膜本体及膜表面两个角度对PVDF膜的亲水化改性进行了综述,介绍了共混、共聚、化学改性、等离子体处理及接枝改性等多种改性方法的机理、特点及改性效果.     

仿生超疏水PVDF膜材的研究与制备

PVDF用于建筑膜材料的表层不能满足防污自洁要求。基于荷叶效应原理,采用模板法制备具有粗糙表面的PVDF膜,以CF4为气氛采用低温等离子体技术对薄膜进行低表面能改性。结果表明,粗糙度对膜的疏水性有影响显著;等离子体改性后膜的疏水性能显著提高,达到静态接触角为166.1°,滚动角1.4°的超疏水;SEM图、AFM图显示膜表面具有类荷叶的微纳米分级结构;等离子改性的条件为处理时间5min,压力60Pa,功率200W。     

超细聚磷酸铵的疏水改性

以甲基含氢硅油为改性剂、活性白土为催化剂,滑石粉、云母粉和疏水白炭黑为辅料,通过疏水保持率、含水率、吸湿性及流动性等检测方法,研究甲基含氢硅油、疏水白炭黑加入时间及加入方式、改性温度、云母粉和滑石粉对超细聚磷酸铵疏水改性影响。结果表明:当甲基含氢硅油用量为12 g时,改性超细聚磷酸铵疏水保持率达94.5%;搅拌速率应遵循先大后小、再增大的规律;待甲基含氢硅油交联聚合完成后,疏水白炭黑一次性加入;改性温度包括分散温度55~60℃,成膜温度100~105℃;与传统灭火材料磷酸二氢铵改性工艺相比,活性白土的加入不改变材料的疏水性。     

基于酶促聚合反应的棉织物疏水改性工艺优化

为改善棉织物的疏水性能,选取酶浓度、温度和处理时间3个影响因素,以静态接触角为评价指标,采用三因素三水平正交试验方法,对基于脂肪酶催化聚合反应的棉织物疏水改性工艺进行优化,结果表明,最优工艺条件为处理时间9 h,温度45℃,酶浓度45%(体积分数),此时棉织物的静态接触角为119.58°,润湿时间达109 s。扫描电镜结果表明改性后棉织物的纤维表面被许多颗粒覆盖。采用基质辅助激光解吸电离飞行时间质谱测试仪,对改性棉织物的纤维素酶水解液进行化学表征,结果表明,在改性后棉织物的纤维素酶水解液中,存在脂肪酶催化合成的聚酯低聚物,最高聚合度为7,具有不同种类端基的聚酯分子的平均聚合度分别为3.27(nCA)、5.26(nCC)、5.66(nAA)。综合物理性能表征及化学表征分析,揭示了脂肪酶催化双酯类单体戊二酸二乙酯与乙二醇二乙酸酯在棉织物表面聚合对棉织物进行疏水改性的作用机制:在棉织物表面酶促生成的疏水性聚酯低聚物分子紧密附着或嵌合在棉织物纤维集合体之间,在其表面形成一薄层疏水防护层,赋予棉织物良好的疏水性能。     

纳米TiO_2的改性及其性能研究

采用KH-570、正辛醇和辛酰氯分别对纳米TiO2进行改性,利用傅立叶红外光谱、差热/热重分析及X-射线衍射仪对改性前后纳米TiO2进行表征,结果表明纳米TiO2的改性为化学改性,改性剂与纳米TiO2表面羟基形成稳定的化学键,但并没有改变纳米TiO2的晶型结构。改性后的纳米TiO2在有机溶剂中的分散性和稳定性提高,尤其是KH-570改性纳米TiO2的效果最好,具有更强的疏水性。KH-570改性纳米TiO2与丙烯酸树脂复合后,能在树脂中均匀分散,不易团聚。     

疏水性材料的等离子体表面改性工艺研究

通过等离子体连续处理仪对疏水性材料表面进行表面改性而提高了其润湿性。研究了不同反应条件对高分子材料表面改性的影响;通过测定样品表面的接触角等性能评价了其表面亲水性的变化。经过等离子体表面处理,聚四氟乙烯的接触角有了显著下降;聚乙烯电池隔膜的吸碱率为自身重量的3.5倍,爬高率初始3 min接近100 mm;硅橡胶的接触角由105°下降到30°;聚酯的接触角由98°到15°。通过对材料表面进行丙烯酸接枝,评价了时效性的影响;初步探讨了真空紫外辐射对表面改性的影响。结果表明:改性后疏水性材料表面的润湿性得到了明显改善,该技术与设备在工业应用方面非常具有推广价值。     

淀粉粒度效应对微细化淀粉/LDPE共混体系相态结构的影响

以玉米淀粉为原料,制备不同粒度梯度的微细化淀粉,将其分别疏水化改性后以相同质量分数与LDPE共混,分析不同拉度微细化淀粉与LDPE共混体系的相态结构。扫描电镜显示,随着淀粉粒度的降低,微细化淀粉在LDPE中的分散性提高;流变学分析表明,MST／LDPE共混体系熔体为非牛顿假塑性流体．随着淀粉粒度的降低,熔体非牛顿指数减小,但粘度变化不显著。淀粉粒度降低有利于改善共混体系的加工性能扣力学性能。     

玉米淀粉醋酸酯的制备及成膜性能

以冰醋酸和醋酸酐为改性剂,浓硫酸作催化剂,合成了玉米淀粉醋酸酯,用傅立叶红外(FT-IR)、扫描电镜(SEM)、差示扫描量热法(DSC)、X射线衍射(XRD)分别对淀粉醋酸酯的结构、形貌、玻璃化转变温度和结晶度等进行测试和表征,分析了不同酯化度对淀粉的微观结构和热性能的影响。结果表明,淀粉经酯化后,结晶度降低,热性能提高,制备的酯化淀粉/聚乙烯醇的复合膜具有较好的力学性能和疏水性。     

接枝共聚法合成高吸水性树脂

以过硫酸钾为引发剂,过硫酸钾与玉米淀粉的质量比为0.014;糊化的玉米淀粉与丙烯酸按质量比1∶6的比例发生接枝聚合反应.反应温度50 ℃,反应时间2.5 h～3.0 h,丙烯酸的中和度为92%,制得高吸水性树脂,并讨论了其吸水性能.在室温、中性酸度环境下,合成的高吸水性树脂吸水倍率最高,可达到560 g/g。     

烯基琥珀酸酐改性MS-1淀粉及表面施胶实验

采用烯基琥珀酸酐(ASA)对MS-1淀粉在湿法条件下进行改性,在MS-1淀粉上引进疏水基团,合成一种新型的淀粉表面施胶剂。探讨了反应过程中反应温度、反应物比例、反应时间对施胶效果的影响。结果表明,其最佳合成工艺条件是,反应温度65℃,m(MS-1淀粉)∶m(ASA)=5∶1,反应时间2h。当施胶质量分数为5%时,施胶度可达206s。并利用红外光谱分析仪、表面张力仪、接触角测定仪、扫描电子显微镜对ASA改性MS-1淀粉的结构与性能进行了表征。红外图谱表明,产物在1569 cm-1出现酯羰基的吸收峰,说明ASA与MS-1淀粉发生了酯化反应。当施胶质量分数为5%时,接触角达133°。     

淀粉与丙烯酸接枝共聚物吸水性能的影响因素研究

采用溶液聚合的方法,制备了淀粉与丙烯酸接枝共聚物;用FTIR等方法对共聚产物结构进行了表征;研究了聚合反应温度、糊化时间、丙烯酸中和度、产物烘干温度、丙烯酸与淀粉不同混合比例等因素对接枝产物吸水性能的影响,优化出了在实验室用玉米淀粉和丙烯酸接枝共聚制备高倍率吸水树脂的工艺条件,制备的吸水树脂吸去离子水近1000g/g.     

Effects of pigeon pea and plantain starches on the compressional, mechanical, and disintegration properties of paracetamol tablets

A study has been made of the effects of pigeon pea starch obtained from the plant Cajanus cajan (L) Millisp. (family Fabaceae) and plantain starch obtained from the unripe fruit of Musa paradisiaca L. (family Musaceae) on the compressional, mechanical, and disintegration properties of paracetamol tablets in comparison with official corn starch BP. Analysis of compressional properties was done by using density measurements, and the Heckel and Kawakita equations, whereas the mechanical properties of the tablets were evaluated by using tensile strength (T--a measure of bond strength) and brittle fracture index (BFI--a measure of lamination tendency). The ranking for the mean yield pressure, P(y), for the formulations containing the different starches was generally corn < pigeon pea < plantain starch while the ranking for P(k), an inverse measure of the amount of plasticity, was pigeon pea < plantain < corn starch, which indicated that formulations containing corn starch generally exhibited the fastest onset of plastic deformation, whereas those formulations containing pigeon pea starch exhibited the highest amount of plastic deformation during tableting. The tensile strength of the tablets increased with increase in concentration of the starches while the Brittle Fracture Index decreased. The ranking for T was pigeon pea > plantain > corn starch while the ranking for BFI was corn > plantain > pigeon pea starch. The bonding capacity of the formulations was in general agreement with the tensile strength results. The disintegration time (DT) of the formulation increased with concentration of plantain and corn starches but decreased with concentration of pigeon pea starch. The general ranking of DT values was plantain < pigeon pea < corn starch. Notably, formulations containing pigeon pea starch exhibited the highest bond strength and lowest brittleness, suggesting the usefulness of pigeon pea starch in producing strong tablets with minimal lamination tendency. Plantain starch, on the other hand, would be more useful where faster disintegration of tablet is desired. The results show that the starches could be useful in various formulations depending on the intended use of the tablets with the implication that the experimental starches can be developed for commercial purposes.     

The Effect of Agglomeration Methods on the Micromeritic Properties of a Maltodextrin Product, Maltrin 150™

Maltrin M150 is a fine powder of maltodextrin which is a carbohydrate product made by controlled hydrolysis of corn starch. Agglomerated Maltrin was prepared using a fluidized bed granulation process and a roller compaction method, respectively. The micromeritic properties of these two granular products were compared. Three different sizes of granules (20/30, 40/50 and 80/100 mesh size) were used in the evaluation. Granules produced by the fluidized bed method showed a relatively low bulk density as compared to the roller compacted granules. As the granule size was reduced, the roller compacted granules showed a decrease in bulk density while an increase in bulk density was seen in the fluidized bed granulated product. A better flowability of the roller compacted granules was demonstrated by a higher flow rate and a lower compressibility index. For a given compression pressure, roller compacted granules produced compacts with a lower tensile strength. A significant work-hardening effect was exhibited by the roller compacted product.     

氧化淀粉胶黏剂的交联改性及其性能研究

用玉米淀粉与过硫酸铵反应制备了氧化淀粉胶黏剂,再与二羟甲基双氰胺(DMDCD)进行交联反应,制备了一种交联改性氧化淀粉胶黏剂。采用红外光谱对样品进行了表征,并讨论了交联改性对氧化淀粉胶黏剂耐水性和贮存稳定性的影响。实验结果表明:DMDCD改性提高了淀粉胶黏剂的耐水性与贮存稳定性;当过硫酸铵质量分数为淀粉质量的1.5%,DMDCD质量分数为淀粉质量的3%时,交联改性氧化淀粉胶黏剂的贮存稳定性在45 d以上,其耐水时间、黏度分别为102 h和1680 mPa.s;红外分析证实了DMDCD与氧化淀粉发生了交联反应。     

Effects of Pigeon Pea and Plantain Starches on the Compressional,Mechanical, and Disintegration Properties of Paracetamol Tablets

ABSTRACT

A study has been made of the effects of pigeon pea starch obtained from the plant Cajanus cajan (L) Millisp. (family Fabaceae) and plantain starch obtained from the unripe fruit of Musa paradisiaca L. (family Musaceae) on the compressional, mechanical, and disintegration properties of paracetamol tablets in comparison with official corn starch BP. Analysis of compressional properties was done by using density measurements, and the Heckel and Kawakita equations, whereas the mechanical properties of the tablets were evaluated by using tensile strength (T-a measure of bond strength) and brittle fracture index (BFI-a measure of lamination tendency). The ranking for the mean yield pressure, P_y, for the formulations containing the different starches was generally corn < pigeon pea < plantain starch while the ranking for P_k, an inverse measure of the amount of plasticity, was pigeon pea < plantain < corn starch, which indicated that formulations containing corn starch generally exhibited the fastest onset of plastic deformation, whereas those formulations containing pigeon pea starch exhibited the highest amount of plastic deformation during tableting. The tensile strength of the tablets increased with increase in concentration of the starches while the Brittle Fracture Index decreased. The ranking for T was pigeon pea > plantain > corn starch while the ranking for BFI was corn > plantain > pigeon pea starch. The bonding capacity of the formulations was in general agreement with the tensile strength results. The disintegration time (DT) of the formulation increased with concentration of plantain and corn starches but decreased with concentration of pigeon pea starch. The general ranking of DT values was plantain < pigeon pea < corn starch. Notably, formulations containing pigeon pea starch exhibited the highest bond strength and lowest brittleness, suggesting the usefulness of pigeon pea starch in producing strong tablets with minimal lamination tendency. Plantain starch, on the other hand, would be more useful where faster disintegration of tablet is desired. The results show that the starches could be useful in various formulations depending on the intended use of the tablets with the implication that the experimental starches can be developed for commercial purposes.     

Influence of Ar plasma treatment on the wetting behavior of pharmaceutical powders

In this study, corn starch and ibuprofen are treated in Argon (Ar) plasma to enhance the wettability of the powders without using any additive or guest particle. The powder and pellets were exposed to the Ar plasma for different time intervals (5–20?min) at optimized pressure and voltage. While the morphological changes due to plasma exposure are captured by SEM, the AFM measurement shows the variations in surface roughness for both corn starch and ibuprofen powders. The XPS and surface energy results confirm that the surface groups change is dominating under initial exposure, but longer exposure creates more damaging effect than building the new active sites at the surface. The contact angle (CA) measurement shows that with increase in treatment time, the CA decrease from 48° to 33° for corn starch and 69° to 51° for ibuprofen. A comparison of experimentally obtained CA and that of theoretically calculated CA shows that there exists some difference. This may be attributed to the absence of surface group contribution in the Wenzel model. The present study shows that short exposure is sufficient enough to improve the wetting where the surface group plays a dominant role over surface roughness.