Preparation of poly(lactic acid) composites containing calcium carbonate (vaterite)

The effect of stearic acid-coated nano calcium carbonate (NCC) on transitions and chain mobility of poly(lactic acid) (PLA) was investigated. Dispersion state of NCC in polymeric matrix was explored using scanning electron microscopy and surface tension component measurements. Trends of PLA transitional phenomena were investigated using the results of dynamical mechanical analysis (DMA) and differential scanning calorimetry (DSC) in the nanocomposite systems based on PLA and NCC. In addition, two types of crystal structures and decreasing the glass transition temperature were distinguished using temperature-modulated DSC (TMDSC). Higher melting points of polymer crystals were found in TMDSC experiments due to low and dynamic heating rate compared to the conventional DSC. Dynamics of polymer chains, affected by NCC, were quantified using cooperativity length, ξ α, and the number of relaxing structural units, Nα, in the glass transition region. NCC particles hindered the cooperative motion of polymer chains at glass transitions and crystallization in TMDSC measurements, whereas the DMA results indicated that NCC particles may act as lubricant and simplified chain mobility.

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Non-isothermal cold crystallization kinetics of poly(lactic acid)/poly(butylene adipate-co-terephthalate)/treated calcium carbonate composites

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-014-4162-z ◽

2014 ◽

Vol 119 (1) ◽

pp. 635-642 ◽

Cited By ~ 30

Author(s):

Nan Shi ◽

Qiang Dou

Keyword(s):

Lactic Acid ◽

Calcium Carbonate ◽

Crystallization Kinetics ◽

Cold Crystallization ◽

Poly Lactic Acid ◽

Kinetics Of

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Comparison between Mechanical and Thermal Properties of Polylactic Acid and Natural Rubber Blend Using Calcium Carbonate and Vetiver Grass Fiber as Fillers

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.410.59 ◽

2011 ◽

Vol 410 ◽

pp. 59-62 ◽

Cited By ~ 9

Author(s):

Punmanee Juntuek ◽

Chaiwat Ruksakulpiwat ◽

Pranee Chumsamrong ◽

Yupaporn Ruksakulpiwat

Keyword(s):

Tensile Strength ◽

Lactic Acid ◽

Thermal Properties ◽

Calcium Carbonate ◽

Impact Strength ◽

Natural Rubber ◽

Poly Lactic Acid ◽

Mechanical And Thermal Properties ◽

Vetiver Grass ◽

Elongation At Break

From our previous study, natural rubber (NR) was used to improve toughness of poly (lactic acid) (PLA). Impact strength and elongation at break of PLA was increased when adding NR. Moreover, by using NR-g-GMA as compatibilizer for PLA and NR blend, impact strength and elongation at break was improved. However, tensile strength and modulus of PLA/NR blend with and without NR-g-GMA were decreased. In this study, calcium carbonate (CaCO3) and vetiver grass fiber were used as fillers in PLA/NR blend. With the addition of CaCO3 into PLA/NR blend with NR-g-GMA, impact strength and modulus of the composite were further increased with a loss in tensile strength. In contrast, the addition of vetiver grass fiber into PLA/NR blend with NR-g-GMA led to an increase in tensile strength and modulus and a decrease in impact strength and elongation at break. The onset degradation temperatures of PLA composites were lower than that of PLA and PLA/NR blend.

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Properties and Skin Compatibility of Films Based on Poly(Lactic Acid) (PLA) Bionanocomposites Incorporating Chitin Nanofibrils (CN)

Journal of Functional Biomaterials ◽

10.3390/jfb11020021 ◽

2020 ◽

Vol 11 (2) ◽

pp. 21 ◽

Cited By ~ 9

Author(s):

Maria-Beatrice Coltelli ◽

Laura Aliotta ◽

Alessandro Vannozzi ◽

Pierfrancesco Morganti ◽

Luca Panariello ◽

...

Keyword(s):

Lactic Acid ◽

Calcium Carbonate ◽

Chain Scission ◽

Poly Lactic Acid ◽

Butylene Succinate ◽

Agar Diffusion Test ◽

Wide Range ◽

Poly Ethylene ◽

Skin Compatibility ◽

Die Extrusion

Nanobiocomposites suitable for preparing skin compatible films by flat die extrusion were prepared by using plasticized poly(lactic acid) (PLA), poly(butylene succinate-co-adipate) (PBSA), and Chitin nanofibrils as functional filler. Chitin nanofibrils (CNs) were dispersed in the blends thanks to the preparation of pre-nanocomposites containing poly(ethylene glycol). Thanks to the use of a melt strength enhancer (Plastistrength) and calcium carbonate, the processability and thermal properties of bionanocomposites films containing CNs could be tuned in a wide range. Moreover, the resultant films were flexible and highly resistant. The addition of CNs in the presence of starch proved not advantageous because of an extensive chain scission resulting in low values of melt viscosity. The films containing CNs or CNs and calcium carbonate resulted biocompatible and enabled the production of cells defensins, acting as indirect anti-microbial. Nevertheless, tests made with Staphylococcus aureus and Enterobacter spp. (Gram positive and negative respectively) by the qualitative agar diffusion test did not show any direct anti-microbial activity of the films. The results are explained considering the morphology of the film and the different mechanisms of direct and indirect anti-microbial action generated by the nanobiocomposite based films.

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