Artigo de peri??dico
Morphology in multilayer blown films of polypropylene and ethylene-octene copolymer blends
Registro en:
0930-777X
3
33
10.3139/217.3526
aguardando
20.321
40.50
Autor
SILVA, J.
ELIAS, M.
LIMA, N.
CANEVAROLO, S.
Resumen
In this work the microstructure of multilayer blown films consisting
of a core layer placed between two external ones is
studied. The core layer is a blend with 70% (w/w) of a homopolypropylene
PP and 30% of a metallocene-catalyzed ethylene-
octene copolymer mEOC (LLDPE or VLDPE), whereas
the external symmetrical layers are composed of LLDPE or
they have the same composition as the core layer. The PP
and PE crystalline phases formed during the film blowing
were investigated by thermal analysis, mechanical properties,
TEM morphology and X-ray diffraction pole figures. These
films successfully combine the high mechanical strength of
PP with the quasi-isotropic behavior of blown PE. Multilayer
film containing PP/mEOC blends, particularly blends of
PP70/LLDPE30, show better balanced tensile properties
when compared at crossed directions. The presence of
VLDPE in the blends shifts downwards the melting and crystallization
temperatures and crystallinity of PP. X-Ray pole
figures suggest the occurrence of epitaxial crystallization of
the PE phase upon the PP crystals in these PP/mEOC blend
films. Coordena????o de Aperfei??oamento de Pessoal de N??vel Superior (CAPES) Conselho Nacional de Desenvolvimento Cient??fico e Tecnol??gico (CNPq) CAPES: BJT 019/2012 CNPq: PQ 311790/2013-5