| Nowadays,energy and environment become two main bottlenecks in the developing society as non-renewable fossil resources such as petroleum and coal emit pollution.Cellulose has been categorized as nontoxic,biodegradable and has ability to modifying to provide cellulose derivatives.It is line ar polymer of 1-4 linked ?-d-glucose,with intensive hydrogen bonding,which makes the derivatization of cellulose more difficult.Cellulose modifications take place by introducing functional groups in order to substitute the free hydroxyl groups within cellulose by using solvents.Recently,ionic liquids(ILs)have been used as media for dissolving and functionalizing cellulose.Reactive extrusion is a technique that can be used for the chemical moditication of polymers,which can melt during processing.It has been applied widely in with some natural polymers(carbohydrate)especially with starch.But the applying of this technique with cellulose is rarely,this limitation is referring to cellulose nature,which does not melt and flow in the extruder.However,the ease of processing and control of reaction conditions makes this technique attractive for cellulose modification if the suitable processing agents or plasticizer such like ILs was mixed with cellulose to improve theprocessability.Because of the application of melt extrusion process for modifying the cellulose it would be sign of progress in the field of cellulose modification,the main objective of this work is to explore the possibility of modification of cellulose through reactive extrusion by using maleic anhydrides as reagent and ionic liquid as plasticizer in order to find out the more economical and environmentally friendly process for cellulose modification.This aim it can be achieve by:?Modification of cellulose with Maleic anhydride in homogenous phase and study the properties of modified cellulose(hold comparison with modified cellulose by reactive extrusion).? Mixing cellulose with Ionic liquid and extrude the mixture with twin screw extruder.? Applying the plasticizer melt spinning for modified cellulose.Dissolution and regeneration of cotton cellulose using ILs(1-butyl-3-methylmidazoliu-mchloride)as solvent has investigated.The best reaction mass ratios(4%)of the cellulose/IL solution were chosen.The maleylation celluloses can be carried out in IL and a wide range of DS values from 0.68 to 1.46.Also,maleic anhydride modified cellulose was prepared through reactive extrusion using twin screw extruder in attend of ILs without any catalyst.The processing technology of extrusion was studied.Degree of substitution in range of 0.13 to 0.86 was obtained.Meanwhile,changing the corresponding parameters related to the modification of cellulose,the best process conditions were configured.The modified cellulose by two ways have been characterized by FT-IR,solid-state CP/MAS 13CNMR,XRD and thermogravimetry analysis.The results which obtained from FT-IR and 13CNMR analysis confirmed that the reaction between cellulose and MA was done.They were shown the same result.Adding appropriate plasticizer into modified cellulose,the melt spinning of cellulose on a conventional melt-spinning equipment was realized successfully.Therheological properties of modified cellulose/plasticizer(IL)melt were studied.The results and melt spinning research showed that the suitable melt spinning temperature for plasticized modified cellulose melts was 175 ?.The properties of cellulose fibers were investigated by SEM.The SEM photomicrographs of cellulose fiber showed that the tenacity could achieve 0.57cN/dtex without drawing.The maleylation cellulose fibers prepared by plasticized melt spinning possess is a new way to try.After reaction,the IL was effectively recycled and was confirmed by 1HNMR spectroscopy.It implies that no chemical reaction occurred during the recycling of IL(BminCl)and it also has high purity. |
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