New aspects of the β–α polymorphic transition in plastically deformed isotactic polypropylene studied by microindentation hardness

Boyanova, M.; Calleja, F. J. Baltá; Fakirov, S.

doi:10.1007/s10853-006-0323-1

Cited by 12 publications

(7 citation statements)

References 24 publications

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“…Another important change that can be observed is the presence of three new peaks associated with metallic copper (face-centered cubic structure, FCC). These peaks were found at 2θ = 43.6, 50.7, and 74.6°, corresponding to planes (111), (200), and (220), respectively [ 40 , 41 , 42 , 43 ].…”

Section: Resultsmentioning

confidence: 99%

Antimicrobial Property of Polypropylene Composites and Functionalized Copper Nanoparticles

et al. 2021

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Copper nanoparticles (CuNPs) functionalized with polyethyleneimine (PEI) and 4-aminobutyric acid (GABA) were used to obtain composites with isotactic polypropylene (iPP). The iPP/CuNPs composites were prepared at copper concentrations of 0.25–5.0 wt % by melt mixing, no evidence of oxidation of the CuNP was observed. Furthermore, the release of copper ions from iPP/CuNPs composites in an aqueous medium was studied. The release of cupric ions was higher in the composites with 2.5 and 5.0 wt %. These composites showed excellent antibacterial activity (AA) toward Pseudomona aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus). The incorporation of CuNP into the iPP polymeric matrix slightly decreased the thermal stability of the composite material but improved the crystallinity and the storage modulus. This evidence suggests that CuNPs could work as nucleating agents in the iPP crystallization process. The iPP/CuNPs composites presented better AA properties compared to similar composites reported previously. This behavior indicates that the new materials have great potential to be used in various applications that can be explored in the future.

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Section: Resultsmentioning

confidence: 99%

Antimicrobial Property of Polypropylene Composites and Functionalized Copper Nanoparticles

et al. 2021

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“…a), after HDT test, the β ‐phase peak weakens dramatically, only a large α ‐crystal peak appears, suggesting the β ‐ α phase transition occurs during the HDT test process. It can be ascribed to the relatively high flexural strain applied on the skin layer, inducing the β ‐ α phase transition . Compared with β ‐PP, α‐ PP possesses higher stiffness, hardness and flexural modulus, resulting from its compact stacking of molecular chains and peculiar crosshatched lamellar morphology.…”

Section: Resultsmentioning

confidence: 99%

Effect of β‐nucleating agent on the crystallization, mechanical properties, and heat resistance of impact‐resistant propylene–ethylene copolymer

Dou

2016

Vinyl Additive Technology

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In this study, β‐nucleated impact‐resistant propylene–ethylene copolymer (IPC) samples were prepared via melt compounding. The effect of β‐nucleating agents (β‐NAs: NT‐A and NT‐C) on the nonisothermal crystallization and melting behaviors of IPC was investigated by means of differential scanning calorimetry (DSC). Spherulitic morphology, mechanical properties and heat resistance of the samples were investigated. The nonisothermal crystallization kinetics was analyzed by Mo's method and the crystallization activation energy was calculated by Kissinger's method. The results show that the content of β‐crystals and the crystallization rate of the β‐nucleated IPCs are greater than those of the neat IPC, indicating that NT‐C is more efficient than NT‐A as a β‐NA. It is also found that the addition of β‐NAs decreases the size and increases the number of spherulites significantly. The Izod notched impact strength and heat deflection temperature (HDT) of IPC are also improved by β‐NAs, accompanied with marginal loss of tensile strength. It is found that the β‐α phase transition occurred during the HDT tests for β‐ nucleated IPCs. It is also indicated that Mo's method well describes the nonisothermal crystallization kinetics of the samples. The addition of β‐NAs remarkably decreases the activation energy of nonisothermal crystallization of IPC. J. VINYL ADDIT. TECHNOL., 24:E36–E47, 2018. © 2016 Society of Plastics Engineers

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“…As efficient nucleating agents, sorbitol derivatives have abilities to make the crystalline form of isotactic polypropylene. This point is well known and has been thoroughly investigated [5][6][7][8] . In contrast with many other nucleating agents, the sorbitol derivatives are designed to dissolve and recrystallize in the melted polymer, causing the formation of a well-dispersed, large surface area, tridimensional nanofibrillar network 9 .…”

Section: Introductionmentioning

confidence: 95%

Influence of Nucleating Agent on Properties of Isotactic Polypropylene

Wang¹,

Zhang²,

Zhu³

et al. 2014

Asian J. Chem.

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As a nucleating agent, 1,3-2,4-di(p-hydroxy)benzylidene sorbitol (DHDBS) at mass percents (0.1, 0.2, 0.3, 0.4 and 0.5 wt. %) was added into isotactic polypropylene matrix by solution/precipitation method and compression-molded method. The crystallization morphology, spherulite dimensions and crystallinity were studied by polarizing microscope, scanning electron microscope and X-ray diffraction. The result showed that 1,3-2,4-di(p-hydroxy)benzylidene sorbitol can induce a crystal and increase the degree of crystallization of isotactic polypropylene The melting peak of isotactic polypropylene analyzed by differential scanning calorimetry was raised. It explained why crystalline perfect degree of polypropylene was increased. Thermogravimetric analysis showed that adding 1,3-2,4-di(p-hydroxy)benzylidene sorbitol can improve the stability of isotactic polypropylene. Mechanical properties of isotactic polypropylene, which were measured by use of impact test enginery and microcomputer control universal test machine, were improved. The optimal amount of nucleating agent was 0.3 wt. %.

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New aspects of the β–α polymorphic transition in plastically deformed isotactic polypropylene studied by microindentation hardness

Cited by 12 publications

References 24 publications

Antimicrobial Property of Polypropylene Composites and Functionalized Copper Nanoparticles

Antimicrobial Property of Polypropylene Composites and Functionalized Copper Nanoparticles

Effect of β‐nucleating agent on the crystallization, mechanical properties, and heat resistance of impact‐resistant propylene–ethylene copolymer

Influence of Nucleating Agent on Properties of Isotactic Polypropylene

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