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Effects of the blending time on the properties and non‐isothermal crystallization behavior of PA6 / EVOH blends
Author(s) -
Lu Weixin,
Lu Chong,
Hu Jing,
Wu Jingjing,
Zhou Qinpeng
Publication year - 2021
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.25695
Subject(s) - materials science , crystallization , crystallinity , rheology , copolymer , polyamide , isothermal process , kinetics , chemical engineering , rheometry , composite material , avrami equation , polymer chemistry , polymer , crystallization of polymers , thermodynamics , physics , quantum mechanics , engineering
Both polyamide 6 (PA6) and ethylene vinyl alcohol copolymer (EVOH) have high fractional crystallinity. Non‐isothermal crystallization kinetics is highly important for the design of processing operations. Furthermore, PA6 and EVOH undergo a chemical reaction to form copolymer when melt blended for a sufficiently long time. Therefore, the effects of the blending time on the mechanical properties, rheological properties, and non‐isothermal crystallization kinetics of PA6/EVOH blends were investigated. Non‐isothermal crystallization kinetics were analyzed through the Jeziorny and Mo′s equations, and the Mo′s equation more appropriately described the crystallization behavior of the blends. Mechanical properties, melt viscosity, and storage modulus gradually enhanced with an increase in the blending time, and the elongation at break first increased and then decreased with an increase in the blending time because when the blending time increased, the degree of the reaction between PA6 and EVOH increased, causing adhesion at interfaces and intermolecular interaction to enhance and causing a decrease in molecular chain fluidity. The former leads to an increase in the mechanical properties of the blend, and the latter renders the regular arrangement of chains for crystallization highly difficulty; hence, crystallization fractions in the blend gradually decrease.