Influence of Polylactide Modification with Blowing Agents on Selected Mechanical Properties

Tor-Świątek, Aneta; Garbacz, Tomasz; Sedlařík, Vladimír; Stloukal, Petr; Kucharczyk, Pavel

doi:10.12913/22998624/80850

Cited by 5 publications

(4 citation statements)

References 12 publications

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“…Fundamentally, PLA has the potential to be processed into microcellular form through various conventional techniques, including compression molding, extrusion, and injection molding . Microcellular extrusion is considered one of the most promising procedures for decreasing density for biomedical application .…”

Section: Introductionmentioning

confidence: 99%

Microcellular antibacterial polylactide‐based systems prepared by additive extrusion with ALUM

Moghaddam

Stloukal

Kucharczyk

et al. 2019

Polymers for Advanced Techs

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This work investigates preparation by extrusion of microcellular antimicrobial polylactide (PLA) with an additive, the latter comprising 1% potassium aluminum sulfate dodecahydrate (ALUM), and 3% or 5% of a mixture of sodium hydrogen carbonate and sodium dihydrogen phosphate (1:1). Study was made as to the properties of the materials, their hydrolysis, release profiles, and antimicrobial properties in comparison with the pure polymer. Measuring the molecular weight of samples by gel permeation chromatography revealed that, during thermal processing, the molecular weight of the PLA prepared with additives mentiond above had reduced by approximately 43%. A mechanical test confirmed a decline in mechanical properties after processing as compared with the pure PLA. Release of the antimicrobial compound and the subsequent antimicrobial activity against Staphylococcus aureus and Escherichia coli was evaluated according to ISO 22196:2007. The release of ALUM from the microcellular specimens took place in two steps. During the first 10 days, the rate of release was extremely high in contrast with the remaining period.However, the release rate of the nonporous sample was seen to equal less than 1% in the first 10 days, a phenomenon probably arising through its less active surface.

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Section: Introductionmentioning

confidence: 99%

Microcellular antibacterial polylactide‐based systems prepared by additive extrusion with ALUM

Moghaddam

Stloukal

Kucharczyk

et al. 2019

Polymers for Advanced Techs

Self Cite

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“…For PLA, rather lower expansion can be expected with chemical blowing agents because of the limited gas yield. Consequently, only a few reports were done, mainly with azodicarbonamide (ADC) [ 43 , 59 , 60 , 84 , 99 , 110 ]. Also, nitrogen is rarely applied as a blowing agent for PLA and rather less expansion was achieved [ 61 ].…”

Section: Processesmentioning

confidence: 99%

Chemical Modification and Foam Processing of Polylactide (PLA)

et al. 2019

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Polylactide (PLA) is known as one of the most promising biopolymers as it is derived from renewable feedstock and can be biodegraded. During the last two decades, it moved more and more into the focus of scientific research and industrial use. It is even considered as a suitable replacement for standard petroleum-based polymers, such as polystyrene (PS), which can be found in a wide range of applications—amongst others in foams for packaging and insulation applications—but cause strong environmental issues. PLA has comparable mechanical properties to PS. However, the lack of melt strength is often referred to as a drawback for most foaming processes. One way to overcome this issue is the incorporation of chemical modifiers which can induce chain extension, branching, or cross-linking. As such, a wide variety of substances were studied in the literature. This work should give an overview of the most commonly used chemical modifiers and their effects on rheological, thermal, and foaming behavior. Therefore, this review article summarizes the research conducted on neat and chemically modified PLA foamed with the conventional foaming methods (i.e., batch foaming, foam extrusion, foam injection molding, and bead foaming).

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“…CBAs are rarely used for the reasons stated above. Examples of CBAs used and reported in the literature in extrusion foaming include azodicarbonamide, which was used mainly with PLA [103,104], PLA blends with poly(butyleneadipate-coterephthalate) (PBAT) [105], and PLA composites. Other studies that used CBAs reported a mixture of sodium bicarbonate and citric acid to obtain the foamed material [106,107].…”

Section: Extrusion Foamingmentioning

confidence: 99%

Forefront Research of Foaming Strategies on Biodegradable Polymers and Their Composites by Thermal or Melt-Based Processing Technologies: Advances and Perspectives

Gonçalves,

Reis,

Fernandes

2024

Polymers

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The last few decades have witnessed significant advances in the development of polymeric-based foam materials. These materials find several practical applications in our daily lives due to their characteristic properties such as low density, thermal insulation, and porosity, which are important in packaging, in building construction, and in biomedical applications, respectively. The first foams with practical applications used polymeric materials of petrochemical origin. However, due to growing environmental concerns, considerable efforts have been made to replace some of these materials with biodegradable polymers. Foam processing has evolved greatly in recent years due to improvements in existing techniques, such as the use of supercritical fluids in extrusion foaming and foam injection moulding, as well as the advent or adaptation of existing techniques to produce foams, as in the case of the combination between additive manufacturing and foam technology. The use of supercritical CO2 is especially advantageous in the production of porous structures for biomedical applications, as CO2 is chemically inert and non-toxic; in addition, it allows for an easy tailoring of the pore structure through processing conditions. Biodegradable polymeric materials, despite their enormous advantages over petroleum-based materials, present some difficulties regarding their potential use in foaming, such as poor melt strength, slow crystallization rate, poor processability, low service temperature, low toughness, and high brittleness, which limits their field of application. Several strategies were developed to improve the melt strength, including the change in monomer composition and the use of chemical modifiers and chain extenders to extend the chain length or create a branched molecular structure, to increase the molecular weight and the viscosity of the polymer. The use of additives or fillers is also commonly used, as fillers can improve crystallization kinetics by acting as crystal-nucleating agents. Alternatively, biodegradable polymers can be blended with other biodegradable polymers to combine certain properties and to counteract certain limitations. This work therefore aims to provide the latest advances regarding the foaming of biodegradable polymers. It covers the main foaming techniques and their advances and reviews the uses of biodegradable polymers in foaming, focusing on the chemical changes of polymers that improve their foaming ability. Finally, the challenges as well as the main opportunities presented reinforce the market potential of the biodegradable polymer foam materials.

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Influence of Polylactide Modification with Blowing Agents on Selected Mechanical Properties

Cited by 5 publications

References 12 publications

Microcellular antibacterial polylactide‐based systems prepared by additive extrusion with ALUM

Microcellular antibacterial polylactide‐based systems prepared by additive extrusion with ALUM

Chemical Modification and Foam Processing of Polylactide (PLA)

Forefront Research of Foaming Strategies on Biodegradable Polymers and Their Composites by Thermal or Melt-Based Processing Technologies: Advances and Perspectives

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