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Characterizing Long Chain Branching in Polypropylene
Author(s) -
Cangussú Manoela E.,
de Azeredo Ana P.,
Simanke Adriane G.,
Monrabal Benjamin
Publication year - 2018
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.201700021
Subject(s) - branching (polymer chemistry) , crystallization , differential scanning calorimetry , polypropylene , fractionation , gel permeation chromatography , materials science , dissolution , polymer , extrusion , reactive extrusion , analytical chemistry (journal) , polymer chemistry , chemistry , chemical engineering , chromatography , thermodynamics , composite material , organic chemistry , physics , engineering
In order to improve elongational viscosity of polypropylene, allowing its use in a wide range of applications, different samples of branched polypropylene have been produced by reactive extrusion and evaluated by different techniques. It is known that the long chain branching (LCB) can act as a nucleating agent in the crystallization process. This is confirmed by differential scanning calorimetry (DSC), optical microscopy, and crystallization analysis fractionation (CRYSTAF), where an increase in the crystallization temperature can be observed when comparing linear and branched samples. In the chemical composition distribution profile of the analyzed samples, it is possible to see differences in the amount of crystallized material among the branched PP samples and it is possible to correlate it with the long chain branching content and distribution, measured by Triple Detector Gel Permeation Chromatography (3D‐GPC), using the Mark‐Houwink plot (MH Plot), conformation plot, and gpcBR methodology. A decrease in dissolution temperature, and an increase in soluble fraction is observed by temperature rising elution fractionation (TREF) at increasing LCB content in the polymer samples. These results indicate that the presence, amount, or distribution of long chain branching affects the crystallization kinetics and the crystal morphology. CRYSTAF and TREF show a good correlation with LCB content measured by GPC.