Font Size: a A A

The Modification Of Rice Straw And The Study Of Its Properties

Posted on:2006-04-16Degree:DoctorType:Dissertation
Country:ChinaCandidate:D NiuFull Text:PDF
GTID:1101360185977803Subject:Materials Physics and Chemistry
Abstract/Summary:PDF Full Text Request
With the development of plastic industry, the pollution of plastics is seriously increasing. The research for degradable plastics has become one of hotspot in the world. In this thesis, etherification reaction was applied to rice straw to modify it into a thermoplastic material. The microstructure and physics and chemical property of modified rice straw were studied.In the present work, Cellulose modification technique was employed and modification rice straw was carried out with NaOH being used as pretreatment agent and swelling agent, epichlorohydrin and benzyl chloride as etherifying agent, deionized water as solvent, and quaternary ammonium salt as phase transfer catalyst The optimum conditions for modification reaction were determined. In the preprocessing time, firstly, soak the rice straw with 10% NaOH for 12 hours, and then boil it for 1 hour. Under the conditions of temperature for 100℃, Modified each gram rice straw with 8.00mL benzyl chloride, 6.00mL de-ionized water, 8.00mL NaOH with the concentration is 6.0mol/L and 0.010g hexadecyl trim ethyl ammonium bromide respond 4 hours and weighting percentage of benzylated straw is 68.78%.. Compared with raw rice straw, modified rice straw changed much in microstructure and decreased in polarity. DSC showed modified rice straw appears the vitrification point is 147.53 ℃, becoming a kind of thermoplastic material.Nature straw and benzylated straw was respectively mixed with polythene (PE) . With the increase of nature straw and benzylated straw content, breaking strength, bending strength and impact strength are all reduced, but the reduction extent of mechanical behaviors for them are little. From the comparison, we can conclude that benzylated straw can be more effective on replacing PE to improve mechanical behaviors than nature straw. Modified straw is more fit to be padding for PE or it's substitute than nature straw.Analyze the rheological property of the blend mixed with Modified rice straw and polythene with capillary rheometer. The effects of the content of straw sample in the blend, shear stress, shear rate and different temperatures on rheological behavior are discussed. The results show that the blend has definite rheology in experimental range and belongs to Non-Newtonian fluid; its viscosity descends with increasing of both shears...
Keywords/Search Tags:rice straw, modification, rheology, viscosity, biodegradation, photodegradation
PDF Full Text Request
Related items