the effect of high-energy electron beam on drawn and undrawn high density polyethylene fibers

نویسندگان

jalil morshedian

yousef jahani

farshad sharbafian

foroogh zarei

چکیده

hdpe monofilaments were obtained using different extruders and drawn by post-extruder equipments. after solidification, drawn and undrawn monofilaments (draw ratio 7:1) were irradiated with 10 mev electron beams in air at room temperature at 25, 50, 75, 100 and 125 kgy dose ranges to induce a network structure. hdpe crosslinking was studied on the basis of gel content measurements. the fibers were examined by differential scanning calorimetry (dsc) and measurements of mechanical properties.it was noted that gel fraction increased with irradiation dose up to 75 kgy and showed a significant increase with draw ratio, but at higher doses remained without considerable change. melting temperature of drawn fiber increased with raising irradiation dose but decreased in undrawn sample. also a bimodal endotherm peak was observed for drawn polyethylene irradiated in air.the changes in melting temperature and appearance of bimodal endotherm were related to the radiation chemistry of polyethylene in the presence of oxygen and interlamellar interactions. heat of fusion and degree of crystallinity slightly increased for undrawn and drawn samples but, heat of crystallization was reduced by increasing irradiation dose due to increase the degree of crosslinking. results of mechanical properties reveal that no significant changes seen in young’s modulus by increasing irradiation dose. as a result of oxidative degradation happened by presence the oxygen molecules during the irradiation process, tensile properties of irradiated fibers decreased but elongation at yield for undrawn and elongation at break for drawn fibers boosted by increasing irradiation dose up to 125 kgy.

برای دانلود باید عضویت طلایی داشته باشید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

The effect of high-energy electron beam on drawn and undrawn high density polyethylene fibers

HDPE monofilaments were obtained using different extruders and drawn by post-extruder equipments. After solidification, drawn and undrawn monofilaments (draw ratio 7:1) were irradiated with 10 MeV electron beams in air at room temperature at 25, 50, 75, 100 and 125 kGy dose ranges to induce a network structure. HDPE crosslinking was studied on the basis of gel content measurements. The fibers w...

متن کامل

the effect of explicit instruction of metacognitive strategies on reading comprehension among iranian high school students

the present study seeks to determine the effect of explicit instruction of metacognitive strategies on iranian high school students’ reading comprehension ability. it also attempts to investigate the relationship between the learners reading comprehension and metacognitive strategies. furthermore, the study investigates whether iranian efl female high school students are high, medium, or low me...

the effect of keeping reflective journals by language instructors on the process of reading comprehension among iranian high school students

خواندن ودرک مطلب از مهمترین مهارتها در یادگیری زبان خارجی محسوب می شود. این تحقیق تاثیر برگه های تامل برانگیز هدایت شده را در ارتقاع مهارت خواندن ودر ک مطلب در دانش اموزان دبیرستانی ایرانی بررسی می نماید. ازمجموع ?2 دانش آموز سال چهارم دبیرستان شهید رجایی شهرستان اسلامشهر¸ پس از اجرای آزمون استاندارد ((nelson 150a تعداد 39 دانش آموز که نمرات آنها یک سطح انحراف معیار بالاتر یا پایین تر ازمعدل قر...

the effect of traffic density on the accident externality from driving the case study of tehran

در این پژوهش به بررسی اثر افزایش ترافیک بر روی تعداد تصادفات پرداخته شده است. به این منظور 30 تقاطع در شهر تهران بطور تصادفی انتخاب گردید و تعداد تصادفات ماهیانه در این تقاطعات در طول سالهای 89-90 از سازمان کنترل ترافیک شهر تهران استخراج گردید و با استفاده از مدل داده های تابلویی و نرم افزار eviews مدل خطی و درجه دوم تخمین زده شد و در نهایت این نتیجه حاصل شد که تقاطعات پر ترافیک تر تعداد تصادفا...

15 صفحه اول

Immobilization of Rhizomucor miehei Lipase on High Density Polyethylene

 Immobilization of Lipase produced from Rhizomucor miehei on HDPE fine powder was investigated. As compared to an aqueous system, immobilization in a non-aquous organic medium such as n-hexane was not successful and caused enzyme denaturation. Prewetting the support with ethanol increased the immobilized protein and enzyme activity as much as 31% and 34%, respectively. The maximum immobilized a...

متن کامل

Quality of High Density Polyethylene on Plain Carbon Steel and the Role of Primers

In this paper , the effect of curing time and temperature as well as various primers on durability of high density polyethylene on plain carbon steel have been investigated. The aim is to increase adhesion, improve durability and also to produce a defect-free in order to improve the corrosion resistance of steel substrate. For this purpose, after surface preparation and applying a primer (zin...

متن کامل

منابع من

با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید


عنوان ژورنال:
polyolefins journal

ISSN 2322-2212

دوره 2

شماره 2 2015

میزبانی شده توسط پلتفرم ابری doprax.com

copyright © 2015-2023