TY - JOUR
T1 - Effect of Thermal History and Shear on the Viscoelastic Response of iPP Containing an Oxalamide-Based Organic Compound
AU - Wilsens, Karel
AU - Hawke, Laurence
AU - de Kort, Gijs
AU - Saidi, Sarah
AU - Roy, Manta
AU - Leone, Nils
AU - Hermida-Merino, Daniel
AU - Peters, Gerrit
AU - Rastogi, Sanjay
N1 - Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/4/9
Y1 - 2019/4/9
N2 - We report on the role of temperature and shear on the melt behavior of iPP in the presence of the organic compound N1,N1′-(propane-1,3-diyl)bis(N2-hexyloxalamide) (OXA3,6). It is demonstrated that OXA3,6 facilitates a viscosity suppression when it resides in the molten state. The viscosity suppression is attributed to the interaction of iPP chains/subchains with molten OXA3,6 nanoclusters. The exact molecular mechanism has not been identified; nevertheless, a tentative explanation is proposed. The observed viscosity suppression appears similar to that encountered in polymer melts filled with solid nanoparticles, with the difference that the OXA3,6 compound reported in this study facilitates the viscosity suppression in the molten state. Upon cooling, as crystal growth of OXA3,6 progresses, the decrease in viscosity is suppressed. Retrospectively, segmental absorption of iPP chains on the surface of micrometer-sized OXA3,6 crystallites favors the formation of dangling arms, yielding OXA3,6 crystallites decorated with partially absorbed iPP chains. In other words, the resulting OXA3,6 particle morphology resembles that of a hairy particle or a starlike polymer chain. Such hairy particles effectively facilitate a viscosity enhancement, similar to branched polymer chains. This hypothesis and its implications for the shear behavior of iPP are discussed and supported using plate–plate rheometry and slit-flow experiments combined with small-angle X-ray scattering analysis.
AB - We report on the role of temperature and shear on the melt behavior of iPP in the presence of the organic compound N1,N1′-(propane-1,3-diyl)bis(N2-hexyloxalamide) (OXA3,6). It is demonstrated that OXA3,6 facilitates a viscosity suppression when it resides in the molten state. The viscosity suppression is attributed to the interaction of iPP chains/subchains with molten OXA3,6 nanoclusters. The exact molecular mechanism has not been identified; nevertheless, a tentative explanation is proposed. The observed viscosity suppression appears similar to that encountered in polymer melts filled with solid nanoparticles, with the difference that the OXA3,6 compound reported in this study facilitates the viscosity suppression in the molten state. Upon cooling, as crystal growth of OXA3,6 progresses, the decrease in viscosity is suppressed. Retrospectively, segmental absorption of iPP chains on the surface of micrometer-sized OXA3,6 crystallites favors the formation of dangling arms, yielding OXA3,6 crystallites decorated with partially absorbed iPP chains. In other words, the resulting OXA3,6 particle morphology resembles that of a hairy particle or a starlike polymer chain. Such hairy particles effectively facilitate a viscosity enhancement, similar to branched polymer chains. This hypothesis and its implications for the shear behavior of iPP are discussed and supported using plate–plate rheometry and slit-flow experiments combined with small-angle X-ray scattering analysis.
KW - FLOW-INDUCED CRYSTALLIZATION
KW - X-RAY-SCATTERING
KW - ISOTACTIC POLYPROPYLENE
KW - NUCLEATING-AGENTS
KW - ENHANCED CRYSTALLIZATION
KW - MULTIPHASE CRYSTALLIZATION
KW - ELASTIC PROPERTIES
KW - STRUCTURAL-CHANGE
KW - BRILL TRANSITION
KW - PARTICLE-SIZE
U2 - 10.1021/acs.macromol.8b02612
DO - 10.1021/acs.macromol.8b02612
M3 - Article
C2 - 30983633
SN - 0024-9297
VL - 52
SP - 2789
EP - 2802
JO - Macromolecules
JF - Macromolecules
IS - 7
ER -