Effect of d-isomer content on strain-induced crystallization behaviour of Poly(lactic acid) polymer under high speed uniaxial drawing

Abstract This research concentrates on the marked discrepancies in the crystalline structure of poly(lactic acid) (PLA) nano- and microfibres, achieved by different annealing strategies. PLA nonwoven mats were produced by high-speed electrospinning. The high-speed production technique allowed the manufacturing of PLA microfibres with diameters of 0.25–8.50 µm with a relatively high yield of 40 g h−1. The crystalline content of the inherently highly amorphous microfibres was increased by two methods; thermal annealing in an oven at 85 °C was compared to immersion in absolute ethanol at 40 °C. The morphology of the fibres was examined by scanning electron microscopy; crystalline forms and thermal properties were assessed using X-ray diffractometry, Raman spectrometry, differential scanning calorimetry (DSC) as well as modulated DSC. As a consequence of 45-min heat treatment, the crystalline fraction increased up to 26%, while solution treatment resulted in 33% crystallinity. It was found that only disordered α′ crystals are formed during the conventional heat treatment; however, the ethanol-induced crystallization favours the formation of the ordered α polymorph. In connection with the different crystalline structures, noticeable changes in the macroscopic properties such as heat resistance and mechanical properties were evinced by localized thermomechanical analysis and static tensile test, respectively.

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Effect of cellulose nanocrystals derived from Dunaliella tertiolecta marine green algae residue on crystallization behaviour of poly(lactic acid)

Carbohydrate Polymers ◽

10.1016/j.carbpol.2021.117881 ◽

2021 ◽

pp. 117881

Author(s):

Kona Mondal ◽

Shinichi Sakurai ◽

Yoko Okahisa ◽

Vaibhav V. Goud ◽

Vimal Katiyar

Keyword(s):

Lactic Acid ◽

Green Algae ◽

Cellulose Nanocrystals ◽

Dunaliella Tertiolecta ◽

Crystallization Behaviour ◽

Poly Lactic Acid

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Study of Strain-Induced Crystallization and Enzymatic Degradation of Drawn Poly(l-lactic acid) (PLLA) Films

Macromolecules ◽

10.1021/ma301482j ◽

2012 ◽

Vol 45 (18) ◽

pp. 7397-7403 ◽

Cited By ~ 29

Author(s):

Deepika Rangari ◽

Nadarajah Vasanthan

Keyword(s):

Lactic Acid ◽

Enzymatic Degradation ◽

Strain Induced Crystallization ◽

Induced Crystallization

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Strain-induced crystallization behaviour of natural rubbers from guayule and rubber dandelion revealed by simultaneous time-resolved WAXD/tensile measurements: indispensable function for sustainable resources

RSC Advances ◽

10.1039/c6ra22455e ◽

2016 ◽

Vol 6 (98) ◽

pp. 95601-95610 ◽

Cited By ~ 14

Author(s):

Yuko Ikeda ◽

Preeyanuch Junkong ◽

Takumi Ohashi ◽

Treethip Phakkeeree ◽

Yuta Sakaki ◽

...

Keyword(s):

Natural Rubber ◽

Crystallization Behaviour ◽

Time Resolved ◽

Sustainable Resources ◽

Strain Induced Crystallization ◽

Induced Crystallization

Guayule and rubber dandelion natural rubbers are useful alternatives forHeveanatural rubber in terms of their strain-induced crystallization behaviours.

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