Silver nanoparticles in isotactic polypropylene (iPP). Part I. Silver nanoparticles as metallic nucleating agents for B-iPP polymorph

Abstract

Isotactic polypropylene (iPP) nanocomposites containing 0.1, 0.2, 0.4 and 0.6 wt % of silver nanoparticles (nAg) were prepared by melt compounding in a one-screw extruder. Selected samples were isothermally recrystallized at different temperatures 50, 75, 100, 125, 130 and 135 °C, and under non-isothermal conditions. The size of the silver particles dispersed in the iPP matrix were estimated by ultraviolet/visible spectroscopy (UV-VIS). The effects of nAg additions on the structure of the iPP were studied by wide angle X-ray scattering (WAXS) and differential scanning calorimetry (DSC) techniques. The results clearly indicate that the addition of nAg induces the formation of the b-iPP polymorph. It is shown that the relative amount of the b form in the recrystallized nanocomposites depends on both the concentration of silver nanoparticles and thermal conditions of recrystallization.

Novel polypropyleneβ‐nucleating agent with polyhedral oligomeric silsesquioxane core: synthesis and application

“…In previous literature, various β ‐NAs have been reported, such as: γ ‐quinacridone E3B, Indigosol Grey IBL and Cibantine Blue 2B pigments, calcium salts of suberic or pimelic acid, calcium tetrahydrophthalate, dicyclohexylterephthalamide, p ‐cyclohexylamidecarboxybenzene, the most commonly used N , N ′‐dicyclohexylnaphthalene‐2,6‐dicarboxamide and others …”

“…In previous literature, various -NAs have been reported, such as: -quinacridone E3B, Indigosol Grey IBL and Cibantine Blue 2B pigments, 12 -16 calcium salts of suberic or pimelic acid, 17 -19 calcium tetrahydrophthalate, 20 dicyclohexylterephthalamide, 21 p-cyclohexylamidecarboxybenzene 22 , the most commonly used N,N ′ -dicyclohexylnaphthalene-2,6-dicarboxamide 23 and others. 24 -31 Polyhedral oligomeric silsesquioxanes (POSSs) are hybrid organic-inorganic nanosized fillers and modifiers widely used for polymer modification. 32 -37 Numerous studies of the application of silsesquioxanes as NAs for iPP have been reported.…”

Silver nanoparticles in isotactic polypropylene. Part II. Molecular modelling of polypropylene chains arrangement on the surface of silver nanoparticles

“…The present article is a continuation of our previous study published as Part I [20]. The aim of this study was to check the above mentioned hypothesis and show the possible arrangements of iPP chains on the surface of silver.…”

“…On the other hand, a comparison of the distances between the chains arranged in the (001) plane in the a form and the lengths of multiplicity of the parameter a of silver unit cell, the conditions for epitaxy are also satisfied. Experimental data presented in [20] showed that besides the majority of b iPP the samples studied contained about 30 % of a form. However, it is well known that a iPP can be formed with no need of any additives.…”

“…In our previous study [20] we have found that the content of b iPP is strongly related to the amount of silver nanoparticles added as well as temperature conditions of crystallization. The highest amount of b form (k parameter) [21] was observed in the samples containing 0.6 wt % nAg after isothermal crystallization at 125°C and 130°C (k » 70 %) as well as in the sample obtained under non-isothermal conditions (k » 67 %).…”