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عنوان:

تهیه کامپوزیت گوگورد اصلاح شده با استفاده از نانو پرکننده های مناسب و بررسی خواص آن



گروه تخصصی:  فنی و مهندسی

سازمان مجری:  معاونت آموزشی جهاددانشگاهی (پایان نامه ها) 

گروه پژوهشی: 

پژوهشگران: 
تاریخ خاتمه:  بهمن 1390

کارفرما: معاونت آموزشی جهاددانشگاهی

خروجی طرح: 
نوع: پایان نامه

 
تلفن: 

نشانی سازمان مجری: 
 

چکیده:

چکیده و متن کامل این مقاله به زبان انگلیسی می باشد.



کلیدواژگان:

 
 
Title:

Preparation of modified sulfur composite by using suitable nanofiller and investigate on its properties



Abstract:

In this thesis, sulfur composites were prepared by “ Direct mixing” of nanofillers (silica, titania, and clay) with sulfur or plasticized sulfur (sulfur polymer). For plasticizing of sulfur, dicyclopentadiene (DCPD), styrene (St), methyl styrene (MSt) or a mixture of DCPD and St were used. FT-IR spectroscopy was used to characterize the structure of synthesized plasticized sulfur. Mechanical properties, thermal behavior, and morphology study of the prepared composites were also investigated. The surfaces of nanosilica and nanotitania particles were modified by coupling agents in aqueous and non-aqueous solvent, respectively, and then characterized by FT-IR, TGA, DLS, ZETA-sizer potentiometery, UV– Visible spectroscopy and dispersability tests. Afterwards, the modified nanofillers were incorporated into sulfur/plasticized sulfur to prepare sulfur composites. The thermo-mechanical properties of the samples were tested in order to evaluate the capability of the mentioned “ Direct mixing” method. Mechanical properties of the sulfur composite containing microsilica (natural quartz) and nanosilica (fumed) were compared together. Sulfur composites were synthesized using sodium monmorilloinite (Na-MMT) and organically monmorilloinite (O-MMT) particles by two methods. In the first method, nanoparticles of monmorilloinite was swelling in methyl styrene then were mixed with molten sulfur as swelling procedure. In the second method, without swelling of the particles, the plasticized sulfur was prepared with a “ Direct mixing” procedure. Plasticized sulfur (using methyl styrene) was mixed with various percentages of Na-MMT or O-MMT in order to find the best percentage ratio as critical value by evaluating of the mechanical tests including compressive, flexural, tensile strengths. Also, the nanostructure of the prepared plasticized sulfur-O-MMT composite was confirmed by XRD, TEM, and SEM techniques. Sulfur with various ratio of DCPD-St mixture was plasticized to find the best mechanical and elongation properties. Then, various percentages of nanosilica (fumed silica) were added to the optimum plasticized sulfur-DCPD-St. The mechanical tests including compressive, flexural and tensile strengths were measured to find the suitable amounts of nanoparticles (critical value). Also, the effect of mixing rate on the plasticized sulfur-nanosilica composite was investigated by mixing rate of 300 and 10000 rpm and the result showed that changing mixing rate could affect the composite properties. The prepared plasticized sulfur-nanocomposites were used as coating agents on the surface of concrete in order to evaluate the adhesive ability of the prepared materials. Overally, the obtained results showed that “ Direct mixing” can be used as simple and cheap method for preparing various nanocomposites specially products of commercial importance. The results also showed that modified nanofilres can enhance the mechanical properties of the plasticized sulfur more than unmodified nanofilers.



Keyword(s): Sulfur,Plasticized sulfur,Modified sulfur,Sulfur composite,Mechanical properties,Nanoclay,Nanosilica,Nanotitania,Nanocomposite