Characterization of polypropylene and ethylene–propylene copolymer blends for industrial applications

Bedia, Elinor L.; Astrini, Nuri; Sudarisman, Aris; Sumera, Florentino C.; Kashiro, Yashikazu

doi:10.1002/1097-4628(20001107)78:6<1200::aid-app40>3.3.co;2-a

Cited by 4 publications

(5 citation statements)

References 8 publications

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“…This effect is less pronounced for PP5341, probably because of an already large amount of fibrils. Figure 7b shows that the addition of 20 wt% random copolymer reduces the tensile strength and increases the elongation at break, confirming the finding of Nitta et al (2005); and Bedia et al (2000). No yielding in the mechanical responses along MD is seen, possibly due to a strong fibril structure of the stretched films (Sadeghi and Carreau, 2008a).…”

Section: Resultssupporting

confidence: 77%

Properties of uniaxially stretched polypropylene films: effect of drawing temperature and random copolymer content

et al. 2010

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Cast films of two linear polypropylenes (PP) having different molecular weights and their blends with 20 wt% random copolymer were prepared by extrusion. The produced cast films were then uniaxially hot drawn at T = 110 and 140 • C under a draw ratio (DR) of 6 using a machine direction orientation (MDO) unit. The effects of drawing temperature and addition of random copolymer on the properties of the films were investigated. The type of crystals (spherulites or fibrils) was studied using differential scanning calorimetry (DSC). The drawing process generated a highly oriented fibrillar crystalline structure, resulting in an increase in the melting point of the films by about 10 • C. The films drawn at 140 • C revealed coexisting lamellae and fibrils whereas at 110 • C mainly a fibrillar structure was observed. Tensile measurements showed a greater strength for the sample stretched at lower temperature (i.e., 110 • C). The effect of drawing temperature and copolymer content on tear resistance was also explored. The medium-molecular weight PP film stretched at 110 • C showed greater tear resistance than at 140 • C. The addition of the random copolymer into the medium-molecular weight PP reduced the tear resistance significantly whereas the impact for the high-molecular weight was not noticeable. Adding the random copolymer significantly decreased the haze for the films and hence drastically improved the clarity.Des feuilles coulées de deux polypropylènes (PP) linéaires avec des poids moléculaires différents et leurs mélanges avec 20% d'équivalent en poids de copolymère aléatoire ontété préparées par extrusion. Les feuilles coulées produites ont alorsétéétiréesà chaud de façon uniaxialeà T = 110 et 140 • C en vertu d'un rapport d'étirage de 6à l'aide d'une unité d'orientation de sens machine. On aétudié les effets de la température d'étirage et l'ajout du copolymère aléatoire sur les propriétés des feuilles. Le type de cristaux (sphérulites ou fibrilles) aétéétudiéà l'aide de la calorimétriè a balayage différentiel (CBD). Le processus d'étirage a produit une structure cristalline fibrillaire fortement orientée, menantà une augmentation du point de fusion des feuilles d'environ 10 • C. Les feuillesétiréesà 140 • C ont révélé des lamelles et fibrilles coexistantes, tandis qu'à 110 • C, on a observé principalement une structure fibrillaire. Les mesures de la traction ont indiqué une résistance supérieure pour l'échantillonétiréà une température basse (c.-à-d., 110 • C). On aégalement exploré l'effet de la température d'étirage et du contenu en copolymère sur la résistance au déchirement. La feuille de PP de poids moléculaire moyenétiréeà 110 • C a démontré une résistance au déchirement supérieur qu'à 140 • C. L'ajout du copolymère aléatoire dans le PP de poids moléculaire moyen a réduit la résistance au déchirement de façon considérable, tandis que l'effet pour le poids moléculaireélevé n'était pas visible. L'ajout du copolymère aléatoire a considérablement réduit le trouble des feuilles et, par conséquent, a amélioré r...

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Section: Resultssupporting

confidence: 77%

Properties of uniaxially stretched polypropylene films: effect of drawing temperature and random copolymer content

et al. 2010

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“…Therefore, the general trend is significant, but individual points are not significant. This relationship has also been observed for PP/EPR blends 69. It is due to the thickening of amorphous layers between lamellae, which is caused by the increased amorphous content of the PP‐ g ‐EPR.…”

Section: Resultssupporting

confidence: 62%

“…The EPR in PP/EPR blends does not usually affect the T m of the PP 40, 68, 70. However, Bedia et al reported a decrease in T m of 2.8°C from homoPP to a 50% EPR blend 69. The lack of change in T m suggests that the incorporation of EPR does not affect lamellar thickness.…”

Section: Resultsmentioning

confidence: 97%

Differential scanning calorimetry of copolymer of isotactic polypropylene backbone with grafted poly(ethylene‐co‐propylene) branches

Whitney¹,

Zhu²

2006

J of Applied Polymer Sci

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A series of graft polymers having polypropylene (PP) backbone and poly(ethylene-co-propylene) (EPR) side chains was prepared. PP backbone molecular weight (M n ) was 28 -98 kg/mol, EPR side chain M n was 2.6 -17 kg/mol, and EPR content was 0 -16 wt %. In this work, thermal analysis of the copolymers was performed using differential scanning calorimetry (DSC). Nonisothermal crystallization was performed at different cooling rates. The DSC thermograms revealed multiple melting peaks for slowly cooled samples, most likely the result of the melting of thinner tangential lamellae followed by the melting of thicker radial lamellae. Equilibrium melting temperature (T m 0 ) was determined using the linear Hoffman-Weeks method. Another approach was also used for determining

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“…Moreover, the size of the rubber particles is decreased when the grafted polymers are added to the blend, in particular, in blends containing both functionalized polymers, this being one of the aspects responsible for the better impact behavior. Bedia et al 35 demonstrated that, as the EPR content increases, the rubber domain dispersed in the continuous matrix increases, this effect being particularly evident at concentrations above 40% of EPR in the blend. On the other hand, they observed that the highest impact strength was obtained at 40% EPR and starts to decrease for higher concentrations.…”

Section: Morphological Analysismentioning

confidence: 99%

Effect of monomethyl itaconate‐grafted HDPE and EPR on the compatibility and properties of HDPE–EPR blends

López–Manchado

Yazdani‐Pedram

Retuert

et al. 2003

J of Applied Polymer Sci

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ABSTRACT:To improve the compatibility and properties of blends based on high-density polyethylene (HDPE) and the ethylene-propylene copolymer (EPR), the functionalization of both through grafting with an itaconic acid derivative, monomethyl itaconate (MMI), was investigated. The grafting reaction was performed at 180°C in a Brabender Plasticorder using an initial monomer concentration of 3 phr in the case of HDPE and 5 phr in the case of EPR. 2,5-Dimethyl-2,5-bis(tert-butylperoxy)hexane was used as a radical initiator for the functionalization of HDPE and dicumyl peroxide was used as a radical initiator for the modification of EPR. The degree of grafting was 1.56% by weight for HDPE and 0.8% by weight for EPR. The effect of grafting on the processability, morphology, and thermal and mechanical properties of the blends are of particular interest. The results show that the grafting reaction increases the toughness and elongation at break of all tested blends and they retained their strength and stiffness. Moreover, the grafted polymers behaved as nucleating agents, accelerating the HDPE crystallization. These results are particularly relevant when both polymeric phases are modified. Morphological studies are in concordance with the mechanical characterization, showing a reduction of the rubber particle size and a better interfacial adhesion when both polymers are functionalized with MMI.

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Characterization of polypropylene and ethylene–propylene copolymer blends for industrial applications

Cited by 4 publications

References 8 publications

Properties of uniaxially stretched polypropylene films: effect of drawing temperature and random copolymer content

Properties of uniaxially stretched polypropylene films: effect of drawing temperature and random copolymer content

Differential scanning calorimetry of copolymer of isotactic polypropylene backbone with grafted poly(ethylene‐co‐propylene) branches

Effect of monomethyl itaconate‐grafted HDPE and EPR on the compatibility and properties of HDPE–EPR blends

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