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SUPERVISOR
Sayed Majed Mortazavi
سیدمجید مرتضوی درچه (استاد راهنما)
 
STUDENT
Leila Noori
لیلا نوری

FACULTY - DEPARTMENT

دانشکده مهندسی نساجی
DEGREE
Master of Science (MSc)
YEAR
1388
owadays, it is one of the human’s goals to produce high water retention goods because of their growing applications. Cellulosic absorbent materials are widely used in all around of the world due to their biocompatibility and economical benefits. Most of the cellulosic absorbents can be used as diaper or sanitary tissues, agriculture, and ion exchange resins .Pulp is used also as a cellulosic absorbent, Cellulosic fibers are able to absorb water, which have an essential role in water absorbency, but their water retention is low. Various factors effect the improving of water retention capacity of the fibers such as improving porous structure of fiber, grafting hydrophilic polymer on the fiber and bulk fiber charge. In this research work, it has been tried to improve water retention of cellulosic materials by grafting reaction with cyclodextrin. Cyclodextri are torus-shaped cyclic oligosaccharide made of six, seven, or eight glycoside units linked by ?(1-4 ) bonds and are called a- ?-, and ?-CD respectively. The hydrophobic internal cavity and the hydrophilic external part of this molecular structure are antagonist feature that are at the origin of the original properties of and scienti?c interest in CDs. This product, issued from enzymatic degradation of starch, has the capability to make inclusions (or host–guest) compounds with aliphatic and especially aromatic molecules. Among the possible applications of CDs, encapsulation of active substances, such a as ?avoring agents, fragrances, pesticides or drugs, is often reported. Such supramolecular compounds are of interest because they increase the solubility of the guest in aqueous media, protect the guest against to oxidation and thermal or chemical degradation, and prevent rapid evaporation of the guest. Ghmati and co-workers grafted acrylamidomethylated ?-cyclodextrin (CDNMA) on the cellulose. Swelling evaluation was carried out by measuring the amount of liquid soaked up by the material as a function of time, until saturation. For the cellulose-g-CDNMA samples, absorption was increased of more than 50%. Fratoni and coworker grafted acrylamidomethylated ?-cyclodextri and monochlorotriazinyl-cyclodextrin (CDMCT) to Tencel and water absorbency was measured for untreated Tencel and for the CDNMA and CDMCT-grafted fabrics in water and in a 1M aqueous NaCl solution. The data show that the hydrophilicity of the fabric surface remains almost unaltered, except when Tencel is grafted with CDNMA; this results in a quite higher water absorbency value. In this research work, scouring and mercerizing were carried out on fibers then ?-cyclodextrin has been bonded to cotton fibers, using citric acid as the crosslinking agent. The effect of some parameters such as cyclodextrin, citric acid, catalyst concentrations and temperature on the weight gained by samples was evaluated. The capacity of the water retention of the samples was evaluated, using Iran 5530 standard. The highest recorded water retention of mercerized fibers was 7/3 g/g and for the sample treated with cyclodextrin was 10/86 g/g. This process has increased 52 percent in water retention capacity of the fibers.
مواد سلولزی جاذب آب در سرتاسر جهان به واسطه زیست سازگار بودن و امتیازات اقتصادی بسیار مورد توجه قرار گرفته¬اند. امروزه تولید کالاهای با قابلیت نگهداری آب بالا، به دلیل کاربرد و تقاضای زیاد آن¬ها از اهداف بشر می¬باشد. جذب و نگهداری آب برای مصارف بهداشتی، کشاورزی(کشت بدون خاک)، مبدل¬های یونی( رزین¬های تعویض یون) حائز اهمیت است. پنبه ساختارمتخلخلی دارد و هنگامی که در آب غوطه¬ور شود، الیاف آن متورم و حفره¬ها پر از آب می¬گردد ولی ظرفیت نگهداری آب الیاف پنبه خام پایین است. دراین پروژه به دلیل اهمیت قابلیت نگهداری آب کالای سلولزی تحت نیرو، با تغییر میزان سیکلودکسترین پیوندزده شده روی کالای پنبه¬ای، تأثیرآن بر روی ظرفیت نگهداری آب بررسی شد. . برای اندازه¬گیری ظرفیت نگهداری آب از روش استاندارد ایران به شماره 5530 استفاده شد و بیشترین میزان نگهداری آب برای الیاف مرسریزه شده 3/7 گرم بر گرم و برای نمونه عمل شده با سیکلودکسترین 86/10 گرم بر گرم می¬باشد. این عملیات باعث افزایش 52 درصدی در ظرفیت نگهداری آب شده است.

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