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Velasco, José Ignácio; Martínez, Alejandro Rosillo; Arencón, D.; Pérez, Miguel Ángel Rodríguez; Saja, J.A. de

doi:10.1023/a:1004565822502

Cited by 23 publications

(18 citation statements)

References 5 publications

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“…The energy absorbed would be dominated by plastic bending at the edges when thinner cell walls exist. In this study, a low stress was applied to the sample compared to that used by the other researchers [10,22,26], so it was expected that deformation of the foam cells would by dominated by cell wall bending and buckling. In addition, because the produced foam had a closed-cell structure, gas compression could take place, thereby providing pneumatic cushioning as an additional energy absorption mechanism [27].…”

Section: Energy Absorptionmentioning

confidence: 99%

“…In most of the previous research on PE foams, the researchers concentrated only on the characterization or testing of foams, while their samples were obtained com-mercially from established industries [9][10][11]. Bearing this scenario in mind, this work presents a study that includes the in-house production of tailored PE foams through the manipulation of processing parameters (foaming temperature) and expandable polymer compound formulation (crosslinking agent and blowing agent), as well as the response of the foams toward mechanical and impact deformation.…”

Section: Introductionmentioning

confidence: 99%

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Effects of parameter changes on the structure and properties of low‐density polyethylene foam

Zakaria¹,

Ariff²,

Sipaut³

2009

Vinyl Additive Technology

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Several parameters, such as crosslinking agent concentration, blowing agent concentration, and temperature, were varied to evaluate their effects on the structure and mechanical properties of low‐density polyethylene (LDPE) foams. Dicumyl peroxide (DCP) was used as crosslinking agent, while azodicarbonamide (ADC) was utilized as the blowing agent at different levels. The formulations were prepared by using a thermostatically controlled heated two‐roll mill and foamed by using a compression molding technique via a single‐stage foaming process at three foaming temperatures (165, 175, and 185°C). The resultant LDPE foams were characterized and found to have a closed cell structure. The density and gel content increased proportionally with crosslinking level, whereas density decreased when ADC level and foaming temperature were increased. Another characteristic evaluated was the foam cell size decreased when the crosslinking level and foaming temperature were increased. In contrast, increasing the ADC concentration only gave a maximum cell size increase up to 6 phr that decreased when 8 phr of ADC was used. Results also indicated that compression stress increased proportionally with DCP level and decreased when ADC concentration and foaming temperature were increased. Impact studies on the prepared foams showed that their ability to absorb impact energy decreased with increasing crosslinking level, foaming temperature, and blowing agent concentration. J. VINYL ADDIT. TECHNOL., 2009. © 2009 Society of Plastics Engineers

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Section: Energy Absorptionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Effects of parameter changes on the structure and properties of low‐density polyethylene foam

Zakaria¹,

Ariff²,

Sipaut³

2009

Vinyl Additive Technology

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“…In talc‐filled PP, the influence of these particles on PP crystallization is singular and is very different that occurs with other inorganic fillers, although having the same laminar morphology 4–6. Studies based on X‐ray diffraction confirm that talc produces a constrained crystalline structure in PP where polymer chains align regularly on the basal planes of talc particles 7, 8. Talc can initiate heterogeneous crystallization, thus changing the morphology, chain orientation, crystal type, and crystallinity degree of PP, conferring significant changes in optical, thermal, mechanical, and barrier properties of the composites 9, 10…”

Section: Introductionmentioning

confidence: 99%

Influence of talc genesis and particle surface on the crystallization kinetics of polypropylene/talc composites

Castillo

Barbosa

Capiati

2012

J of Applied Polymer Sci

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Talc is a laminar silicate, considered as an excellent nucleating agent for polypropylene (PP) crystallization. However, properties of PP/talc composites depend on the morphology, size, and surface of mineral particles. In this sense, talc from several ores, having different morphology, imparts specific characteristics on these materials. Also, taking into account that PP-talc adhesion is not necessarily good due to the apolar character of PP, talc surface has been modified in order to increase this parameter. In this work, the effects of talc genesis, geomorphologic aspects, and particle surface characteristics on crystallization of PP/talc composites are analyzed. Isothermal crystallization of PP/talc composites was studied by using differential scanning calorimetry, based on Avrami model. The final crystalline morphology of talc-filled PP was analyzed by means optical microscopy. The results show that the blocky talc morphology favors even more the crystallization compared to the platy one, at the same particle size. Taking into account the surface treatment studied in this work, the talc surface is made hydrophobic and the particle delamination is favored. As a consequence, so-modified talc is very effective in increasing the crystallization temperature of PP and the nuclei number that grow during the crystallization with respect to the untreated talc.

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“…However, T c and Δ H c present a small variation with talc concentration. It can be explained from the fact that the nucleating effect is dominant during PP crystallization, but saturation is reached at about 1 wt% of talc [19]. Indeed, the addition of A10A talc leads to composites with T c slightly lower than A10 ones: T c reaches up to 125.6°C with 10 wt% of A10A and 126.5°C with the same concentration of A10.…”

Section: Resultsmentioning

confidence: 99%

“…The smaller the particle size, the greater the surfaces, consequently the more uniform the stress transfer throughout the composite which favors the yield stress. Also, the increment in σ y may be associated with the finer crystalline morphology (smaller and thinner lamellar spherulites) by talc nucleated PP crystallization [19]. In this sense, a smaller spherulitic size is usually related to a greater yield stress [25].…”

Section: Resultsmentioning

confidence: 99%

Surface‐modified talc particles by acetoxy groups grafting: Effects on mechanical properties of polypropylene/talc composites

Castillo

Barbosa

Capiati

2012

Polymer Engineering & Sci

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This article deals with the effects of surface‐modified talc particles on mechanical properties of polypropylene (PP)/talc composites. These materials were prepared by injection molding of PP blended with different concentrations of nontreated and treated talc, under the same processing conditions. Differential thermal calorimetry and scanning electron microscopy were used to assess thermal properties and morphology of the final composites. The reinforcing effect of talc, either treated or nontreated surface, on PP is analyzed through the tensile properties as a function of the mineral content (0–10 wt%). Morphological structure of composites revealed that the talc treatment improved the particle dispersion and distribution within the PP matrix and enhanced the interfacial PP‐talc adhesion. The mechanical properties of these composites, especially the Young modulus, tensile strength and elongation at break, were found to be improved respect to PP‐untreated talc ones. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

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Untitled

Cited by 23 publications

References 5 publications

Effects of parameter changes on the structure and properties of low‐density polyethylene foam

Effects of parameter changes on the structure and properties of low‐density polyethylene foam

Influence of talc genesis and particle surface on the crystallization kinetics of polypropylene/talc composites

Surface‐modified talc particles by acetoxy groups grafting: Effects on mechanical properties of polypropylene/talc composites

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