High molecular weight polypropylene nanospheres: Synthesis and characterization

Abstract

The high molecular weight (MW) polypropylene with average particle size of 60 nm was synthesized by controlled growth mechanism using ZieglerNatta 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 À25 to À118C. 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.

Kinetics of thermal degradation and estimation of lifetime for polypropylene particles: Effects of particle size

“…Due to higher compactness of chains, it takes much more time to attain the thermal equilibrium as well as degradation process occurred slowly. Additionally, these results may be attributed to the smaller particle size, which may have different surface morphology, surface roughness, crystal structure and higher crystallinity for PP nanoparticles compared with the microsized particles [24]. In this circumstance it is important to mention that the purity of PP macro-, micro-and nanoparticles is same and confirmed by FTIR spectroscopy (figure not shown here).…”

Polypropylene nanosphere: particle size and crystal structure

“…The PP nano and micro particles with high molecular weight were synthesized using the method as discussed in our previous work and the chemical structure was studied through FTIR [18][19][20]. The morphology, particle size and its distribution were studied through SEM, TEM and AFM.…”

“…The authors would like to mention that though the particle size is in nanometer scale but the molecular weight of this nano sized PP is equal to the commercially available PP. The synthesis method has been discussed in detail by the authors [18][19][20].…”

“…We can assert that till date no work is available, which will throw some light on preparation and/or characterization of nanoscale PP without disturbing its high molecular weight. In these perspectives, very recently we have reported a unifi ed approach for the synthesis of PP nanoparticles with spherical shape and standardized the process [18][19][20]. This method has been standardized based on the polymerization condition, recrystallization of polymer with varying polymer concentration, types of solvent used, processing temperature and shear rate.…”

Non-isothermal melt crystallization kinetics of anhydrite-filled polypropylene composites

“…， esistance especially at low temperature considerably limits its application [1,2] . Therefore, numerous studies have been reported concerning the reinforcement of PP using different types of inorganic minerals in order to achieve improvement in many aspects [3] . These include increase of modulus and ， ， strength improved barrier properties increase in sol-， vent and heat resistance good optical transparency and ， reducing the production cost of molded products etc.…”