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High molecular weight polypropylene nanospheres: Synthesis and characterization
Author(s) -
Paik Pradip,
Kar Kamal K.
Publication year - 2007
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.26177
Subject(s) - crystallinity , materials science , scanning electron microscope , differential scanning calorimetry , polypropylene , particle size , transmission electron microscopy , fourier transform infrared spectroscopy , nanoparticle , chemical engineering , particle (ecology) , polymer chemistry , nanotechnology , composite material , physics , oceanography , geology , engineering , thermodynamics
The high molecular weight (MW) polypropylene with average particle size of 60 nm was synthesized by controlled growth mechanism using Ziegler–Natta catalyst. The atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) studies showed that PP nanoparticles were spherical in shape. Structure and crystallinity were concomitantly studied through Fourier transform infrared spectroscopy and X‐ray diffraction, respectively. It shows nanospherical PP particles with more crystallinity (∼ 75%) compared with macrosized PP (∼ 59%). In addition, differential scanning calorimetry studies revealed the finite particle size effect on T g and the scale dependence T g followed a first order exponential trend. As particle size goes down to nano‐ scale from macrosize, continuous elevation of T g 's were observed from −25 to −11°C. This phenomenon was directed to configuration entropy of single spherical nanoparticles of PP. The mechanical properties and surface roughness were also evaluated through AFM. At last, the properties of nanosized PP were compared with micron and macrosized particles. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007