Influence of stearic acid treatment of filler particles on the structure and properties of ternary-phase polypropylene composites

Premphet, K.; Horanont, P.

doi:10.1002/(sici)1097-4628(19991227)74:14<3445::aid-app19>3.0.co;2-0

Cited by 86 publications

(54 citation statements)

References 26 publications

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“…Two boundary structures may form in such multicomponent materials: the two components, i.e. the elastomer and the filler, can be distributed separately from each other in the polymer matrix [18][19][20], or the elastomer may encapsulate the reinforcement to create embedded structure [11][12][13]21]. The actual structure is determined by the adhesion and shear forces prevailing in the melt during homogenization, the first favors embedding because of thermodynamic reasons, while the second promotes separate dispersion through the shearing of the elastomer layer apart from the filler [22].…”

mentioning

confidence: 99%

Wood fiber reinforced multicomponent, multiphase PP composites: Structure, properties, failure mechanism

Sudár¹,

Burgstaller²,

Renner³

et al. 2014

Composites Science and Technology

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Polypropylene (PP) was reinforced with wood flour and impact modified with elastomers to increase stiffness and impact resistance simultaneously. Elastomer was added in 0, 5, 10 and 20 wt%, while wood content changed from 0 to 60 wt% in 10 wt% steps. Structure and adhesion were controlled by the addition of functionalized (maleated) polymers. Composites were homogenized in a twin-screw extruder and then injection molded to tensile bars. The results showed that composite structure is determined by the relative strength of adhesion and shear forces prevailing during processing. Structure can be controlled by the application of functional polymers within limits. Although embedding is favored by thermodynamics and further promoted by coupling, de-encapsulation occurs at the large shear stresses of injection molding even in the presence of a functionalized elastomer. Composite properties depend on composition, increasing elastomer content results in decreasing stiffness and strength. Model calculations showed that the elastomer does not contribute to load bearing, average stress in the matrix increases with increasing elastomer content. Local stresses and adhesion define the initiation of deformation processes around wood particles, which start at the same stress irrespectively of elastomer content. Local processes determine the mechanism of failure and composite strength independently of their mechanism.

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mentioning

confidence: 99%

Wood fiber reinforced multicomponent, multiphase PP composites: Structure, properties, failure mechanism

Sudár¹,

Burgstaller²,

Renner³

et al. 2014

Composites Science and Technology

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“…from each other in the polymer matrix [13][14][15], or the elastomer can encapsulate the reinforcement to create embedded structure [6][7][8]16]. The actual structure is determined by the adhesion and shear forces prevailing in the melt during homogenization, the first favoring embedding because of thermodynamic reasons, while the second separate dispersion through the shearing apart of the elastomer layer from the wood fiber [17].…”

mentioning

confidence: 99%

Tensile and impact properties of three-component PP/wood/elastomer composites

Keledi

Sudár

Burgstaller³

et al. 2012

Express Polym. Lett.

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Polypropylene (PP) was reinforced with wood flour and impact modified with elastomers to increase stiffness and impact resistance simultaneously. Elastomer content changed in four (0, 5, 10 and 20 wt%), while that of wood content in seven steps, the latter from 0 to 60 wt% in 10 wt% steps. Structure and adhesion were controlled by the addition of functionalized (maleated) polymers. Composites were homogenized in a twin-screw extruder and then injection molded to tensile bars. Fracture resistance was characterized by standard and instrumented impact tests. The results showed that the components are dispersed independently of each other even when a functionalized elastomer is used for impact modification, at least under the conditions of this study. Impact resistance does not change much as a function of wood content in PP/wood composites, but decreases drastically from the very high level of the PP/elastomer blend to almost the same value obtained without impact modifier in the three-component materials. Increasing stiffness and fiber related local deformation processes led to small fracture toughness at large wood content. Micromechanical deformation processes depend mainly on the strength of PP/wood interaction; debonding and pull-out take place at poor adhesion, while fiber fracture dominates when adhesion is strong. Composites with sufficiently large impact resistance cannot be prepared in the usual range of wood contents (50–60 wt%)

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“…It is not usual to observe an invariable impact resistance in an iPP composition while the mechanical endurance is introduced, and one possible explanation is given by the formation of a new beta crystalline phase [1,2,22] .…”

Section: Waxd (Wide Angle X-ray Diffractometry)mentioning

confidence: 99%

“…Tjong et al [1] analyzed iPP composites having up to 40% of CaCO 3 and concluded that a drop in impact resistance and yield strength with increasing filler content is due to a decrease in the concentration of the tougher polymer matrix, an increase in the amount of the weaker filler/matrix interface, and to the debonding of the filler from the polymer matrix. Premphet & Horanont [2] demonstrated that up to 10% in volume of surface treated CaCO 3 , iPP composites may exhibit higher impact strength, however, concomitantly, a significant reduction in the tensile yield strength. Many researchers [1][2][3][4][5][6][7] have studied the toughening of iPP with CaCO 3 , so the improvement of the impact strength followed by the reduction of yield strength, flexural strength and modulus of the composites are the ordinary outcome.…”

Section: Introductionmentioning

confidence: 97%

“…Premphet & Horanont [2] demonstrated that up to 10% in volume of surface treated CaCO 3 , iPP composites may exhibit higher impact strength, however, concomitantly, a significant reduction in the tensile yield strength. Many researchers [1][2][3][4][5][6][7] have studied the toughening of iPP with CaCO 3 , so the improvement of the impact strength followed by the reduction of yield strength, flexural strength and modulus of the composites are the ordinary outcome. It was also observed, that among different types of calcium carbonate particles, those which were surface treated and submicron sized gave composites with superior combination of mechanical properties [3][4][5][6][7] .…”

Section: Introductionmentioning

confidence: 99%

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Influence of the beta crystalline phase fraction on the mechanical behavior of polypropylene/calcium carbonate/polypropylene - graft - maleic anhydride composites

2014

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Abstract:The formation of the crystalline phase of polypropylene in the presence of four different types of CaCO 3 was studied. All composites were prepared by melt mixing and extrusion and the concentration of CaCO 3 was maintained at 5 wt %. Furthermore, in another series of composites, 5 wt % of polypropylene-graft-maleic anhydride (PP-g-MA) was added for comparison. The tensile strength, flexural modulus and impact resistance of the composites were determined. The composites were also analyzed by DSC (differential scanning calorimetry) and WAXD (wide angle x-ray diffractometry) in order to understand and quantify the beta crystalline phase. The results indicated that the composite having the smallest CaCO 3 size and PP-g-MA presented the best combined mechanical properties, therefore, the highest impact resistance, flexural modulus and tensile strength were observed, which were attributed to the proportionally higher concentration of beta crystalline phase.

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Influence of stearic acid treatment of filler particles on the structure and properties of ternary-phase polypropylene composites

Cited by 86 publications

References 26 publications

Wood fiber reinforced multicomponent, multiphase PP composites: Structure, properties, failure mechanism

Wood fiber reinforced multicomponent, multiphase PP composites: Structure, properties, failure mechanism

Tensile and impact properties of three-component PP/wood/elastomer composites

Influence of the beta crystalline phase fraction on the mechanical behavior of polypropylene/calcium carbonate/polypropylene - graft - maleic anhydride composites

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