توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱Effect of Epoxidized Natural Rubber on Dispersion of Organoclay and Curing Behavior of NR\BR\Organoclay Nanocomposites
نویسنده(ها): ،
اطلاعات انتشار: کنفرانس بین المللی فرآورش پلیمرها، سال
تعداد صفحات: ۴
In this work nanocomposite based on (NR\BR\Clay, 60\40\5) were prepared through melt blending in an internal mixer, at a temperature of 80°C and a rotor speed of 60 rpm. Different amounts (5, 10, 15 phr) of Epoxidized Natural Rubber (ENR) with 50 mol% epoxidation (ENR 50) was used as a compatibilizer and its effects on dispersion of organoclay and the curing behavior of prepared nanocomposites was investigated. Evaluation of curing properties through using rubber process analyzer (RPA) equipment showed decrease in the scorch and also cure times of nanocomposites by employing of ENR. Minimum torque of rheometry (ML) of nanocomposites was decreased in presence of ENR; however the difference between maximum and minimum torque of rheometrey (MH–ML) was increased which was attributed to increasing of crosslink density. Nanocomposites exhibited higher tensile properties with the incorporation of ENR due to the more intercalation of silicate layers by the rubber which was shown in the X–ray diffraction (XRD) patterns.<\div>

۲The Effect of Mixing Procedure on Rheology and Morphology of Bitumen Modified by Polybutadiene –Nanoclay
نویسنده(ها): ،
اطلاعات انتشار: کنفرانس بین المللی فرآورش پلیمرها، سال
تعداد صفحات: ۴
A 60\70 penetration grade bitumen was modified by incorporating a combination of high cis 1,4–Polybutadiene Rubber (PBR) and organophilic montmorillonit Closite 15A (C15A). Two procedures were employed to prepare the mixtures: 1) The three components PBR, C15A and Bitumen were loaded into a high shear mixer simultaneously; 2) Closite 15A was initially mixed with the rubber by using melt blending method and then obtained nanocomposite was blended with bitumen in the high shear mixer. The X–ray diffraction analysis results showed different structure with various level of intercalation for the mixtures prepared by the two mentioned procedures. Meanwhile morphological analysis by using florescence microscopy showed better dispersion of PBR in bitumen in presence of C15A. Rheological properties of nanocomposite modified bitumen were evaluated in linear viscoelastic region and higher complexmodulus and lower damping factor was observed for modified systems in compare with neat bitumen<\div>

۳Influence of Rubber Concentration on the Microstructure and Performance Properties of High Cis1, 4–Polybutadiene Rubber– Modified Bitumen
نویسنده(ها): ،
اطلاعات انتشار: کنفرانس بین المللی فرآورش پلیمرها، سال
تعداد صفحات: ۴
In this study, different concentrations (0–7 wt %) of high cis1, 4–Polybutadiene rubber (PBR) was used to modify a 60\70 penetration grade bitumen. Blending of the ingredients of the mixtures was carried out in a high shear mixer. Florescence microscopy was used to investigate the morphology of the mixtures. The results showed that the mixtures containing low concentration of rubber reveals disperse–matrix morphology and increasing the amount of rubber leads to formation of co–continuous morphology. Furthermore, the structural difference between the studied systems was also reflected by measuring of viscosity versus shear rate. To evaluate high temperature storage stability, ring and ball softening point and needle penetration tests were carried out on top and bottom of aluminum tube samples and the results were compared. This showed considerably better high temperature storage stability for the mixture with matrix–dispersed droplet morphology. Susceptibility of modified bitumen to rutting was determined by dynamic creep test, which consisted of 100 cycles of 1–s creep followed by 9–s recovery. The accumulated shear compliance during repeated creep and recovery tests was calculated. Modified system showed smaller accumulation compliance in compare with neat bitumen<\div>

۴Influence of the kind of organoclay on morphology and mechanical properties of (SBR\NBR) as an immiscible rubber blend
اطلاعات انتشار: کنفرانس بین المللی فرآورش پلیمرها، سال
تعداد صفحات: ۴
In this study to prepare nanocomposite two different kinds of organo–modified–layered nanosillicates (Closite 30B:C30B, Closite 15A:C15A) were employed in acrylonitrile butadiene rubber (NBR), styrene butadiene rubber (SBR) and their blend (SBR\NBR; 60\40). Mixing was carried out in an internal mixer at temperature of 90°C. Several compounds with and without organoclay were mixed and cured by using peroxide cure system. X–ray diffraction (XRD) analysis and Field Emission Scanning Electron Microscopy (FE–SEM) were performed to determine the nanocomposites morphology and structure. The obtained results showed that Mooney viscosity of the rubber and the affinity between organoclay and the rubber affect the height of the organoclay’s inter layer spacing. The use of C30B in NBR resulted in more inter layer spacing than that of C15A, which was attributed to greater affinity between C30B and NBR. In SBR nanocomposites containing C30B or C15A, due to higher Mooney viscosity of the used SBR with respect to NBR, greater inter layer spacing of organoclay was observed. Higher viscosity of rubber causes higher shear mixing which resulted in more intercalation of organoclay. Curing characteristics and mechanical properties of the samples were evaluated and the results showed slightly increase in maximum torque of rheometry as well as improvement of tensile properties of a given nanocomposite compare to its correspond unfilled compound.<\div>

۵The Effect of Multiwall Carbon Nanotube Concentration on The Electrical properties of (MWCNT–Polypropylene–Styrene Butadiene Rubber) Nanocomposite
اطلاعات انتشار: پانزدهمین کنگره ملی مهندسی شیمی ایران، سال
تعداد صفحات: ۴
Thermoplastic elastomers are known as the polymeric materials which exhibit the elastic and mechanical properties of cross–linked rubbers as well as the melt processability of thermoplastics. In this study nanocomposites based on dynamically vulcanized thermoplastic elastomer of (polypropylene (PP)\styrene butadiene rubber (SBR) containing multi wall carbon nanotube (MWCNT)) were prepared by melt mixing method. The effect of using different amounts of MWCNT on electrical properties of the prepared nanocomposites was investigated. Results of electrical experiments showed that by incresing the amount of CNT, the electrical conductivity of the nanocomposite increased slowly. This was attributed to a agglomoration of rubber particles and stranding of nano particles between them which prevents the formation of enough CNT–CNT network<\div>
نمایش نتایج ۱ تا ۵ از میان ۵ نتیجه