Preparation of polylactic acid (PLA) foams with supercritical carbon dioxide and their applications for reflectors of white light-emitting diode (LED) lamps

Extrusion assisted by supercritical CO 2 (sc-CO 2) is an emerging method for the microcellular foaming of polymer. Instead of batch foaming, which requires formation of single-phase polymer/CO 2 solution in long cycle times, the extrusion assisted by supercritical fluids overcomes this issue by providing rapid mixing and dissolution of CO 2 in the polymer melt. Because the sc-CO 2 is soluble in many molten polymers and acts as a removable plasticizer, its introduction in an extruder will permit a decrease of the processing temperature. This technic allows the use of fragile component like active molecule or starchy and proteinaceous materials. At the end of the extruder, the pressure drop will create instability and phase separation with the creation of porosity. This review is dedicated to the extrusion assisted by sc-CO 2 with different types of biopolymer. Industrial application domains include agro-food, biomedical, pharmaceutical, packaging and many others.

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“…Kuo et al [61] worked on a different problematic. They managed to create PLA foams with high reflectivity.…”

Section: Other Applicationsmentioning

confidence: 99%

Extrusion assisted by supercritical CO 2 : A review on its application to biopolymers

Chauvet

Sauceau

Fages

2017

The Journal of Supercritical Fluids

126

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“…The water absorption decreases as the content of the bicycloalkyl group increases. The lowest water absorption occurs for a copolymerization ratio of 10% [22,23,24].…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Physical Properties of Non-Crystalline Nylon 6 Containing Dimer Acid

Huang

et al. 2019

Polymers

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In this study, a long carbon chain dimer acid is introduced into a nylon 6 structure and is copolymerized with different structural amines to produce amorphous nylon 6 by 4,4′-methylenebis(2-methylcyclohexylamine) (MMCA) in different copolymerization ratios. The effect of different structures and copolymerization ratios on the properties of nylon 6 is determined, along with the thermal properties, crystallinity, water absorption, dynamic mechanical properties, and optical properties. It is found that the melting point and the thermal cracking temperature Td10 of nylon 6 are respectively between 176 °C and 213 °C and 378 °C to 405 °C. The effect of introducing a bicyclohexane group containing a methyl side chain is greater than that of a meta-benzene ring, so COMM (synthesized by Caprolactam (C), dimer oleic acid (OA), and 4,4′-Methylenebis(2-methylcyclohexylamine) (MMCA)) has the lowest melting point, enthalpy, and crystallinity. As the copolymerization ratio increases, its thermal properties decrease. 10% is the lowest crystallinity. The amine structure containing a bicycloalkyl group has lower water absorption and a 10% copolymerization ratio gives the lowest water absorption. It contains the bicycloalkyl group, COM (synthesized by Caprolactam (C), dimer oleic acid (OA) and 4,4′-Methylenebis(cyclohexylamine) (MCA)), which has the highest loss modulus. The lowest loss modulus is noted for a copolymerization ratio of 7% and the value of tan δ increases as the copolymerization ratio increases. The introduction of nylon 6 with the bicycloalkyl groups, COMM and COM, significantly increases transparency. As the copolymerization ratio increases, the transparency increases and the haze decreases. The best optical properties are achieved for 10% copolymerization.

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“…Finally, in all cases the produced porous structures had pore diameters of several micrometers. The production of pores with considerably smaller sizes (even in the nanoscale) would expand the field of applications of such flexible porous structures to far more advanced applications . In this direction, the possibility of synthesizing flexible PLLA block copolymers that possess self‐assembly capabilities in supercritical CO 2 and CO 2 expandable liquids may be explored .…”

Section: Discussionmentioning

confidence: 99%

Preparation of porous poly(L-lactic acid)-co -(trimethylene-carbonate) structures using supercritical CO₂ as antisolvent and as foaming agent

et al. 2016

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In this work, porous structures of poly(L-lactic acid)-co-(tri-methylene-carbonate) (PLLA-co-TMC) were successfully fabricated using two experimental methods, that is, using supercritical CO 2 as antisolvent and as foaming agent through the pressure induced phase separation technique. Considering the phase inversion method, the effect of the initial polymer concentration of the solution, pressure, and temperature on the morphology of the final porous structure (pore size, porosity, and cell density) was investigated. The L-L demixing process was suggested as the dominant mechanism for the phase separation and pore production. The temperature window, for which PLLA-co-TMC porous structures are successfully produced using the pressure induced phase separation technique, was determined at 150 and 210 bar. The effect of temperature on the final porous structure was investigated.

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Preparation of polylactic acid (PLA) foams with supercritical carbon dioxide and their applications for reflectors of white light-emitting diode (LED) lamps

Cited by 17 publications

References 27 publications

Extrusion assisted by supercritical CO 2 : A review on its application to biopolymers

Extrusion assisted by supercritical CO 2 : A review on its application to biopolymers

Synthesis and Physical Properties of Non-Crystalline Nylon 6 Containing Dimer Acid

Preparation of porous poly(L-lactic acid)-co -(trimethylene-carbonate) structures using supercritical CO₂ as antisolvent and as foaming agent

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Preparation of polylactic acid (PLA) foams with supercritical carbon dioxide and their applications for reflectors of white light-emitting diode (LED) lamps

Cited by 17 publications

References 27 publications

Extrusion assisted by supercritical CO 2 : A review on its application to biopolymers

Extrusion assisted by supercritical CO 2 : A review on its application to biopolymers

Synthesis and Physical Properties of Non-Crystalline Nylon 6 Containing Dimer Acid

Preparation of porous poly(L-lactic acid)-co -(trimethylene-carbonate) structures using supercritical CO2 as antisolvent and as foaming agent

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Product

Resources

About

Preparation of porous poly(L-lactic acid)-co -(trimethylene-carbonate) structures using supercritical CO₂ as antisolvent and as foaming agent