Effect of processing conditions on the cell morphology distribution in foamed injection molded PLA samples

Volpe, Valentina; Filitto, Martina De; Klofacova, Vera; Santis, Felice De; Pantani, Roberto

doi:10.1063/1.5016727

Cited by 4 publications

(5 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the examined literature, only a few publications on the foam injection molding of PLA with CBAs can be found [ 75 , 96 ]. Common physical blowing agents used for foam injection molding of PLA include N 2 [ 74 , 90 , 92 ] and CO 2 [ 58 , 76 , 246 ]. As far as the data given in the publications about injection-foamed PLA (cf.…”

Section: Processesmentioning

confidence: 99%

See 1 more Smart Citation

Chemical Modification and Foam Processing of Polylactide (PLA)

et al. 2019

View full text Add to dashboard Cite

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).

show abstract

Section: Processesmentioning

confidence: 99%

“…Intensive work on FIM of PLA with nitrogen was carried out by the group of Pantani and Volpe [ 89 , 90 , 92 , 93 , 95 ]. In an early work, they pointed out that higher injection flow rates resulted in a more homogeneous cell morphology and density reduction along the flow path.…”

Section: Processesmentioning

confidence: 99%

Chemical Modification and Foam Processing of Polylactide (PLA)

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The few examples found used Azodicarbonamide [119,120]. The main PBAs used in foam injection moulding include CO 2 [121,122] and N 2 [123][124][125][126]. Nitrogen has a higher cell nucleating force, although it shows a lower solubility in polymers compared to carbon dioxide [53].…”

Section: Foam Injection Mouldingmentioning

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

View full text Add to dashboard Cite

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.

show abstract

“…Different works have reported the use of SFCs as foaming agents for PLA. Nitrogen was used for injection molding [ 63 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 ] and batch foaming [ 72 ]. However, Li et al [ 73 ] showed that the solubility of CO 2 in PLA is approximately ten times that of N 2 .…”

Section: Introductionmentioning

confidence: 99%

Foaming of PLA Composites by Supercritical Fluid-Assisted Processes: A Review

et al. 2020

View full text Add to dashboard Cite

Polylactic acid (PLA) is a well-known and commercially available biopolymer that can be produced from different sources. Its different characteristics generated a great deal of interest in various industrial fields. Besides, its use as a polymer matrix for foam production has increased in recent years. With the rise of technologies that seek to reduce the negative environmental impact of processes, chemical foaming agents are being substituted by physical agents, primarily supercritical fluids (SCFs). Currently, the mass production of low-density PLA foams with a uniform cell morphology using SCFs as blowing agents is a challenge. This is mainly due to the low melt strength of PLA and its slow crystallization kinetics. Among the different options to improve the PLA characteristics, compounding it with different types of fillers has great potential. This strategy does not only have foaming advantages, but can also improve the performances of the final composites, regardless of the implemented foaming process, i.e., batch, injection molding, and extrusion. In addition, the operating conditions and the characteristics of the fillers, such as their size, shape factor, and surface chemistry, play an important role in the final foam morphology. This article proposes a critical review on the different SCF-assisted processes and effects of operating conditions and fillers on foaming of PLA composites.

show abstract

Effect of processing conditions on the cell morphology distribution in foamed injection molded PLA samples

Cited by 4 publications

References 18 publications

Chemical Modification and Foam Processing of Polylactide (PLA)

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

Foaming of PLA Composites by Supercritical Fluid-Assisted Processes: A Review

Contact Info

Product

Resources

About