Premium
Real‐time Raman spectroscopic measurement of crystallization kinetics and its effect on the morphology and properties of polyolefin blown films
Author(s) -
Cherukupalli Srinivas S.,
Gottlieb Sarah E.,
Ogale Amod A.
Publication year - 2005
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.22357
Subject(s) - linear low density polyethylene , crystallinity , materials science , crystallization , raman spectroscopy , composite material , polypropylene , ultimate tensile strength , polyolefin , crystallization of polymers , polyethylene , tacticity , polymer , chemical engineering , optics , polymerization , physics , layer (electronics) , engineering
The nonisothermal crystallization half‐time (t 0.5 ), defined as the time taken for a polymer film to reach half of its equilibrium crystallinity, was estimated from Raman spectroscopic measurements of crystallinity during blown film extrusion of a linear low‐density polyethylene (LLDPE) and an isotactic polypropylene (i‐PP). The crystalline a‐ and c‐axis orientation of LLDPE and i‐PP films, respectively, increased with decreasing crystallization half‐time. The transverse direction tensile modulus and tear strengths for LLDPE films also increased with decreasing half‐time. However, for i‐PP films, only the transverse direction tear strength increased with decreasing t 0.5 , while the machine direction properties did not show a significant dependence on half‐time. Our real‐time Raman spectroscopy studies provide experimental evidence to theories proposed in the literature1–3 with regards to the influence of the nonisothermal crystallization process (along the film axis) on the imparted final film structure. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1740–1747, 2005