Optimization of the crystallinity of polypropylene/submicronic-talc composites: The role of filler ratio and cooling rate

Abstract

Abstract. Micronic and submicronic mineral fillers recently appeared as efficient reinforcing agents for polyolefins in addition to the benefit of bypassing the exfoliation/dispersion problem encountered in the case of incorporation of nanoscopic fillers such as clay. Submicronic-talc, designated as µ-talc, belongs to this kind of new fillers. This work was aimed at searching to optimize the crystallinity ratio of isotactic polypropylene in the presence of µ-talc in relation to the filler ratio of the composites and the cooling rate from the melt. In order to highlight the efficiency of the µ-talc on the crystallization of polypropylene comparison has been made with PP composites containing conventional talc particles. The study has been carried out on samples having µ-talc weight fractions covering the range 3-30%. In the context of optimizing the crystallinity ratio of the polypropylene matrix in the composites, calorimetric experiments have been planned using a full factorial design. The results were statistically processed by analysis of the variance via mathematical models for predicting the crystallinity ratio in relation to the cooling rate and the filler ratio. Contour graphs have been plotted to determine the effect of each parameter on crystallinity. The cooling rate proved to have a significantly stronger influence on crystallinity than the type and content of filler.

Shrinkage and Warpage Optimization of Expanded‐Perlite‐Filled Polypropylene Composites in Extrusion‐Based Additive Manufacturing

“…F20 exhibits for all investigated filler loadings, except for 30 vol%, a higher nucleating activity than F80. This could be due to the larger specific surface area of the smaller particles, as reported for other fillers, such as microfibrous cellulose or talc …”

“…This could be due to the larger specific surface area of the smaller particles, as reported for other fillers, such as microfibrous cellulose [89] or talc. [90] 3.1.2. Morphology Figure 5 depicts the fracture surface of the cryo-fractured filaments of the compounds PP/F20-30 and PP/F80-30.…”

Application of ashes as filling in reprocessed polypropylene: thermomechanical properties of composites

“…Rigid particles must be separated and create a free volume in the blend in a submicronic size level, which it is explained with the mechanism of cavitation in the hardened rubber systems [9] . Through time, the fillers most commonly used in polypropylene have been calcium carbonate and talc [10][11][12] , however, currently it continues being studied alternatives for the use of inorganic fillers from physic-chemical, thermal or biological degradation of agricultural residues as the case of ashes [13] . Rice husk is one of the main products of agricultural waste, according to statistics of FAO, rice global production was approximately of 756.7 millions tons in 2017, moreover, a production of 989.96 tons were reported by DANE in Colombia in the first half of 2017 [14] .…”

Chemical degradation of reinforced epoxy‐cement composites under CO2‐rich environments

“…In contrast, yield stress and Charpy notch toughness decrease with increasing talc content; at the highest filler concentration both properties decrease below the matrix level. Although there is a vast literature on the production of composites with talc and different polymer matrices, such as polypropylene , polyurethane , and poly(vinyl alcohol) , the research related to talc‐filled epoxy resins is limited and therefore it is still open to further investigation.…”