Batch foaming of chain extended PLA with supercritical CO2: Influence of the rheological properties and the process parameters on the cellular structure

Corre, Yves-Marie; Maazouz, Abderrahim; Duchet, Jannick; Reignier, Joël

doi:10.1016/j.supflu.2011.03.006

Cited by 199 publications

(136 citation statements)

References 35 publications

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“…The observed increase could be due to shorter overlapping time of macromolecules during elongational flow. Thus, the occurrence of the strain hardening behavior of linear PLA has been reported in few studies and might be due to its stereo-regularity [15][16][17][18][19][20][21][22][23][24][25][26][27]. In fact, the stereo-regularity of high L-content PLA (98% of L-content in our case) may allow them to form a range of structures when stretched, where helical conformations may form in the melt as a precursor to strain-induced crystallization.…”

Section: Uniaxial Extensional Experimentsmentioning

confidence: 83%

“…According to Figure 6b,c, the Cox-Merz rule works fairly well with neat polymers into the shear thinning region but still shows slightly deviation for the modified polymers and their blends. The polydispersity and the heterogeneity explain this deviation from the rule [12][13][14][15][16][17][18][19][20][21][22]. By this way, the elongation properties during processing can ben also influenced.…”

Section: Linear Viscoelastic and Shear Capillary Flow Properties Of Nmentioning

confidence: 99%

“…Yamane et al, showed that the addition of small amounts of poly(D,L-lactic acid) (PDLA) into PLLA could lead to strain-hardening in poly(L-lactic acid) (PLLA) melts due to the stereocomplex formation acting as branching points on the PLA chains. The effects of chain branching of PLA on foaming ability have been investigated by extensional flow experiment [14,16,17]. The authors found that the chemical chain-extension enhanced the extensional flow of PLA where a relevant strain hardening appeared due to the presence of long chain branches when the macromolecular chain disentanglement rate is too low in relation with the deformation rate.…”

Section: Introductionmentioning

confidence: 99%

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Biopolymer Blends Based on Poly (lactic acid): Shear and Elongation Rheology/Structure/Blowing Process Relationships

2015

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This study was dedicated to the blown film extrusion of poly(lactic acid), which mainly presents poor shear and elongation viscosities, and its blends. In order to enhance its melt strength, two main routes were selected (i) a structural modification through chain extension and branching mechanisms by adding a reactive multifunctional epoxide (named Joncryl) and (ii) blending with poly(butylene adipate-co-terephtalate), named PBAT in presence (or not) of Joncryl. The effects of the reactive agent on the shear and elongation rheology, morphological, and interfacial properties of the blends were systematically investigated. A decrease of the interfacial tension has been also demonstrated according to the deformed drop retraction method (DDRM). Hence, the role of Joncryl as a compatibilizer was highlighted. Consequently, finer morphology of the dispersed phase was obtained. Furthermore, the impact of the two modification routes on the blown film extrusion ability of PLA has been studied. Based on the improved shear and elongational rheological properties, a great enlargement of the blowing processing window of PLA modified with Joncryl was demonstrated. Indeed, with the addition of Joncryl into OPEN ACCESSPolymers 2015, 7 940 PLA-PBAT blends, a reduction of the instability defects has been detected. Finally, the induced crystalline structure and the thermo-mechanical properties of blown films were shown to be improved.

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Section: Uniaxial Extensional Experimentsmentioning

confidence: 83%

Section: Linear Viscoelastic and Shear Capillary Flow Properties Of Nmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Biopolymer Blends Based on Poly (lactic acid): Shear and Elongation Rheology/Structure/Blowing Process Relationships

2015

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“…Low melt strength of PLA induces cell coalescence during cell growth. Addition of chain extenders to PLA increased the rheological properties of PLA, and depending on this, cell morphology is enhanced [43][44][45].…”

Section: Polylactic Acid-based Foamsmentioning

confidence: 98%

Thermoplastic Foams: Processing, Manufacturing, and Characterization

Altan¹

2018

Recent Research in Polymerization

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Polymer foams have wide application area due to their light weight, resistance to impact, high thermal insulation, and damping properties. Automotive, packing industry, electronic, aerospace, building construction, bedding, and medical applications are some of the ields that polymer foams have been used. However, depending on their cell structure-open or closed cell-polymer foams have diferent properties and diferent application areas. In this work, the most used thermoplastic foams with closed cells such as polypropylene, polyethylene, and polystyrene or polylactic acid have been focused. Their melt strength, degree of crystallinity for semi-crystalline ones, and viscosity have great importance on cell morphology. Cells in small diameter with high dense in polymer matrix are preferable. However, obtaining ine cells is not easy in each case, and it is still under investigation for some polymers. There are several ways to improve cell morphology, and one of them is addition of nanoparticle to the polymer. During foaming process, nanoparticles behave like nucleating agent that cells nucleate at the boundary between polymer and the nanoparticle. Besides, foaming agents contribute the homogenous dispersion of the nanoparticles in the polymer matrix, and this improves the properties of the polymer foams and generates multifunctional material as polymer nanocomposite foams.

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“…Koros' result agrees well with the diffusivity coefficient from this study since the experimental conditions are similar (i.e., 25°C, 5.5 MPa vs. 35°C, 2.3 MPa). 2 systems The dielectric constants shown in Figure 2 are the average values from three different experiments measured at 1 kHz, at a temperature of 25°C, a relative humidity of 45% for data consistency. The difference in polymer weight percentage changes in the polymer/gas systems, reported in Figure 1, were normalized and used in the comparison between dielectric constant change and the weight percentage change experiments during CO 2 desorption.…”

mentioning

confidence: 99%

A new gas/supercritical fluid (SCF) diffusivity measurement method for CO2 saturated polymer systems using a dielectric property

Yao¹,

Lee²

2017

Express Polym. Lett.

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Batch foaming of chain extended PLA with supercritical CO2: Influence of the rheological properties and the process parameters on the cellular structure

Cited by 199 publications

References 35 publications

Biopolymer Blends Based on Poly (lactic acid): Shear and Elongation Rheology/Structure/Blowing Process Relationships

Biopolymer Blends Based on Poly (lactic acid): Shear and Elongation Rheology/Structure/Blowing Process Relationships

Thermoplastic Foams: Processing, Manufacturing, and Characterization

A new gas/supercritical fluid (SCF) diffusivity measurement method for CO2 saturated polymer systems using a dielectric property

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