کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5190573 1381211 2005 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Micromechanical interpretation of the modulus of ethylene-(meth)acrylic acid copolymers
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آلی
پیش نمایش صفحه اول مقاله
Micromechanical interpretation of the modulus of ethylene-(meth)acrylic acid copolymers
چکیده انگلیسی
Statistical incorporation of a comonomer into polyethylene is well known to reduce its crystallinity, and consequently the small-strain modulus. However, we have found that when the comonomer is methacrylic or acrylic acid, the modulus of homogeneous copolymers initially decreases and then increases with increasing comonomer content. The modulus increase is traced to an elevation of the amorphous phase glass transition temperature (Tg) with comonomer content; Tg passes through room temperature at comonomer contents sufficiently low that substantial crystallinity remains. When the modulus is measured at temperatures above Tg, such that the amorphous phase is fully relaxed, a monotonic increase in modulus with crystallinity is both anticipated and observed. Several two-phase composite models are investigated to describe the modulus vs. crystallinity data above Tg; the Davies model provides a good quantitative description for the copolymers examined. The Davies model may also be applied at temperatures where the amorphous phase is incompletely relaxed, to extract its contribution to the semicrystalline polymer's modulus.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer - Volume 46, Issue 20, 23 September 2005, Pages 8838-8845
نویسندگان
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