Nucleation and crystallization of polypropylene by mineral fillers: relationship to impact strength

McGenity, P.M.; Hooper, Jessica; Paynter, Chris; Riley, Andrew M.; Nutbeem, Chris; Elton, N. J.; Adams, James M.

doi:10.1016/0032-3861(92)90804-6

Cited by 158 publications

(112 citation statements)

References 25 publications

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“…In fact, the predominant deterioration of mechanical properties of PP by nucleating mineral fillers has been reported in the literature. 75 Load cycling the materials below the yield exhibits macroscopic and nanoscopic fatigue detected from a decay of the peak stresses and peak nanostructure parameters, respectively. From the respective lifetimes we have for the first time assessed the reinforcement of the composite and the weakening of the PP by the MMT.…”

Section: Discussionmentioning

confidence: 99%

Properties and Semicrystalline Structure Evolution of Polypropylene/Montmorillonite Nanocomposites under Mechanical Load

et al. 2011

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Small-angle X-ray scattering (SAXS) monitors tensile and load-cycling tests of metallocene isotactic polypropylene (PP), a blend of PP and montmorillonite (MMT), and two block copolymer compatibilized PP/MMT nanocomposites. Mechanical properties of the materials are similar, but the semicrystalline nanostructure of the PP differs. This is explained by a nucleation effect of the MMT. Competitive crystal growth diminishes crystallite sizes. The reinforcing effect of the MMT filler appears consumed by weakening the PP matrix. Decays of mechanical and nanostructure response in dynamic load cycling indicate materials fatigue. Lifetimes describe the reinforcing and weakening effects. Addition of 3% MMT halves the fortifying effect of the PP nanostructure. A net gain of reinforcement (11%) is observed with the highly compatibilized composite in which the strength of the semicrystalline PP is reduced to 25%. Other results concern the evolution of Strobl's block structure and void formation during tensile loading.

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Section: Discussionmentioning

confidence: 99%

Properties and Semicrystalline Structure Evolution of Polypropylene/Montmorillonite Nanocomposites under Mechanical Load

et al. 2011

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“…All three methods of the pre-treatment of nanoadditives incorporated into the PP matrix did not show any differences in crystallization temperatures. However, the rate of PP crystallization in the fibres containing nCaCO 3 is higher than for C30B at the same cooling rate, which demonstrates the decrease of T c or W c , mainly in the case of the nCaCO 3 -based composite [17]. This means that at these conditions, the C30B does not behave like a nucleating agent.…”

Section: Thermal Properties Of Pp/ncaco 3 and Pp/c30b Nanocomposite Fmentioning

confidence: 90%

“…Nanoclay Cloisite 30B-C30B consists of plate-shaped filler particles with high aspect ratio which produce more numerous nucleating sites for PP crystallization than do CaCO 3 nanoparticles, which have spherical particles and lower aspect ratio is [17]. The chemically modified CaCO 3 caused significant changes in the thermal behaviour mainly during PP crystallization.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Inorganic Nanoadditives on the Thermal, Mechanical and UV Radiation Barrier Properties of Polypropylene Fibres

Ujhelyiová¹,

Slobodová²,

Ryba³

et al. 2012

OJOPM

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The objective of this study of modified polypropylene (PP) fibres using nanoadditives (nano-CaCO 3 and Cloisite 30B) was to determine the influence of these additives on thermal and mechanical properties, but especially on the barrier properties of the nanocomposite fibres against UV radiation. The DSC data obtained from measurements of PP/CaCO 3 or PP/C30B nanocomposite fibres were used for determination of the constants n and K of the Avrami equation and in the estimation of other thermal properties of the fibres, such as their crystallization half-time t 1/2 , rate of crystallization  1/2 , the necessary time for maximum crystallization t max and free energy per unit area of surface in the lamella perpendicular to the axis of a high-molecular chain  e . The nano-CaCO 3 or Closite 30B fillers (pre-treated separately in three different solvents: glycerine, acetone and water) did not influence the melting temperatures but caused an increase in PP crystallization temperatures in comparison with the pure PP fibres. The pre-treatments of nanoadditives resulted in increase of n, K,  1/2 values and decrease of t 1/2 , t max as well as the values of free surface energies per unit area of the modified PP fibres. There was also observed a decrease in the mechanical properties, however, there was an increase of barrier properties against UV radiation of nanocomposite PP fibres in comparison with neat PP fibres, which was one of the main objectives of the study.

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“…Isotactic polypropylene (iPP) filled with mineral particles such as calcium carbonate (CaCO 3 ) or with short glass fibers has been the subject of a lot of research [1][2][3][4][5][6][7][8]. The role of fillers in polymer based composites is multiple: it helps reducing the composite cost as it is generally less expensive than the polymer, but it also contributes to improving the mechanical performances and the physical properties if properly dispersed in the polymer matrix.…”

Section: Introductionmentioning

confidence: 99%

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

Makhlouf¹,

Satha²,

Frihi³

et al. 2016

Express Polym. Lett.

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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.

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Nucleation and crystallization of polypropylene by mineral fillers: relationship to impact strength

Cited by 158 publications

References 25 publications

Properties and Semicrystalline Structure Evolution of Polypropylene/Montmorillonite Nanocomposites under Mechanical Load

Properties and Semicrystalline Structure Evolution of Polypropylene/Montmorillonite Nanocomposites under Mechanical Load

The Effect of Inorganic Nanoadditives on the Thermal, Mechanical and UV Radiation Barrier Properties of Polypropylene Fibres

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

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