الفهرس 
Chapter 1- IntroductionOnly 14 pages are availabe for public view
 |  | from | 145 |  |  |
| | | from | 145 | | |
Abstract
Summary
In this work, dissolving of cellulose of rice straw with ionic liquid and prepa- ration of cellulose derivatives like methylcellulose (MC) and carboxymethyl cellulose (CMC) which are valued by modifying them into MC hydrogel and CMC hydrogel and using them in the preparation of absorbed paper where they added separately during the preparation of paper making sheet. In this process, they are characterized by their properties (tensil strength, absorbance..).
6-1- Raw Material Analysis:
Agriculture residue (i.e. rice straw) was characterized before and after converting it to the pulp with a high content of the ash and lignin.
6-2- Preparation of Pure Cellulose from Rice Straw:
Delignification of cellulose process (bleaching process) was carried out to obtain pure cellulose. the lignin content was minimized to reach 0.08%. The FT-IR of the delignified Rs pulp was studied to identify the characteristic groups. SEM was performed and fibers of cellulose were clearly appeared as a separated fibers.
6-3- Dissolution of cellulose:
In our work, cellulose was dissolved in ionic liquid. Cellulose solutions was prepared using 1-butyl-3-methylimidazolium-chloride [BMIM ]+Cl-, both methyltion and carboxylation processes were carried out in the presence of [BMIM ]+Cl-.
6- 4- Preparation of Cellulose Derivatives:
6- 4-1- Preparation of Methylcellulose:
Methylcellulose was made from rice straw as mentioned in the experimental part and SEM for MC-Rs illustrated that cellulose fiber where changed from the individ- ual fibers to compact and swollen fibers, which appears as branched fibers having more pores. This increases the absorbing properties of MC-Rs, also FT-IR spectra was performed for MC-Rs.
6-4-2- Preparation of Carboxymethylcellulose:
Carboxymethylcellulose was made from Rice straw as mentioned in the experimental part. SEM of CMC-Rs shows that cellulose fibers was transferred to a tube and gave the cellulose absorbing property to absorb water or any solvent and changed to a very viscous part.Its dissolving or swelling character depends on the DS value.
6-4-3 Preparation of Hand made-Paper Sheet:
The same pulp which resulted from pulping of rice straw and converted into 5 sheets of paper. MC and CMC were loaded into the paper sheet as 5 % (w/w) of the sheet.
6-4-4-Addition of MC and CMC in Hand made Paper-sheet:
MC and CMC were added at equal amount of starch and hydroxyl ethyl cellulose, this solution was added to the paper pulp during formation of the paper sheet (in paper making machine). The paper sheets were tested for both optical and mechanical properties.
6-4-5-Modification of MC and CMC into MC-hydrogel and CMC –hydrogel:
MC and CMC were modified to hydrogel through treatment with neutral acrylic acid in the presence of potassium persulfate and crosslinker. After gelation and formation of hydrogel the absorption test was carried out, CM percent of absorption was (400%) within five minutes and by increasing the amount of water, the swelling of the membrane increases till it reaches (700%). CMC percent of absorption was 445%, and by increasing the amount of water absorbed till (600%), the CMC hydrogel becomes viscous liquid which dries within (30 minutes) returning to its dry state.
6-4-6-Addition of MC-hydrogel and CMC–hydrogel to Hand-made Paper-sheets:
Modified MC and CMC-hydrogel were added to bleached rice straw pulp during preparation of the paper sheet in the paper making sheet machine where it filled the pores between the fibre then the paper was dried and tested for absorbance of water. The hand-made sheets of modified MC-Hydrogel absorbed 455% water from its weight within 2 min and reached up to 773% after 6 min. While CMC-Hydrogel absorbed paper sheet can absorb water up to 600% from its weight within 6 min. Both CMC-hydrogel and MC-hydrogel can be used as absorbed paper for different purposes.
6-5-Recommendations:
- Agriculture residues can be used for the production of valuable products which have benefits for our environment instead of burning it and causing great environmental air pollution and many diseases.
- Cellulose/ILs technology is considered as ecofriendly and in the nearest future it may will go to replace the traditional cellulose dissolution processes to produce regenerate fiber by the green process.
- Rice straw can be used for the preparation of cellulose derivatives i.e. MC, CMC, in the presence of ionic liquid 1-butyl-3 methylimidazolium chloride. The effectiveness of the ILs in biomass dissolution allows broadening the conversion of biomass derived products to multi-functional copolymer.
- Modification of both methylcellulose or carboxymethylcellulose to methylcellulose-hydrogel and carboxymethylcellulose- hydrogel for preparation of absorbed paper which can be used in a large scale of industries.
- Focusing efforts into how developing the efficiency of the dissolution power of IL and reduce the dissolution time. Furthermore, it has to be ensured that the contam- ination of the environment is as low as possible.