Effect of processing conditions on the development of morphological features of banded or nonbanded spherulites of poly(3-hydroxybutyrate) (PHB) and polylactic acid (PLLA) blends

2011 ◽  
Vol 51 (11) ◽  
pp. 2191-2202 ◽  
Author(s):  
Ahmed Mohamed El-Hadi
Keyword(s):  
Polylactic Acid ◽  
Morphological Features ◽  
Processing Conditions

The effect of processing conditions for polylactic acid based fibre composites via twin-screw extrusion

2013 ◽  
Vol 33 (7) ◽  
pp. 648-662 ◽  
Author(s):  
Michael A Gunning ◽  
Luke M Geever ◽  
John A Killion ◽  
John G Lyons ◽  
Clement L Higginbotham
Keyword(s):  
Polylactic Acid ◽  
Processing Conditions ◽  
Twin Screw Extrusion ◽  
Fibre Composites ◽  
Screw Extrusion ◽  
Twin Screw

Effect of kaolin nanofiller and processing conditions on the structure, morphology, and biofilm development of polylactic acid

2015 ◽  
Vol 132 (42) ◽  
pp. n/a-n/a ◽  
Author(s):  
Edwin A. Segura González ◽  
Dania Olmos ◽  
Gustavo González-Gaitano ◽  
Belén Orgaz ◽  
Javier González-Benito
Keyword(s):  
Polylactic Acid ◽  
Processing Conditions ◽  
Structure Morphology ◽  
Biofilm Development

scholarly journals Effective methods for evaluating the properties of polymer products

2020 ◽  
pp. 69-71
Author(s):  
N. N. Tikhonov ◽  
N. Yu. Nikolaeva ◽  
O. I. Kladovschikova
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Vickers Microhardness ◽  
Acoustic Method ◽  
Morphological Features ◽  
Processing Conditions ◽  
Microhardness Test ◽  
Ultra High Molecular Weight

The application of the acoustic method and the Vickers microhardness test allow obtaining information on the effect of processing conditions on the morphological features and properties of products made of ultra-high molecular weight polyethylene.

Oriented polylactic acid/graphene oxide nanocomposites with high mechanical and thermal properties

2021 ◽  
pp. 089270572110386
Author(s):  
Ehsan Bagheri ◽  
Hadi Rahnama ◽  
Mohammad Ali Hassannia ◽  
Tayebeh Behzad ◽  
Peiman Mosaddegh
Keyword(s):  
Graphene Oxide ◽  
Polylactic Acid ◽  
Barrier Properties ◽  
Polymer Chains ◽  
Mechanical And Thermal Properties ◽  
Drawing Ratio ◽  
Processing Conditions ◽  
Structural Studies ◽  
Scanning Calorimetry ◽  
Thermal Stabilities

Oriented polylactic acid (PLA)/graphene oxide (GO) nanosheets tapes were prepared via uniaxial solid state drawing. The effect of various drawing conditions, including drawing ratio (DR), temperature (DT), and speed (DS) on mechanical, thermal, structural, and barrier properties were studied. Structural studies showed oriented structure for the drawn tapes with aligned polymer chains and GO nanosheets. Differential scanning calorimetry revealed improved glass transition temperature (Tg) and crystallinity (Xc) after drawing. In addition, Tg and Xc were increased more by increasing DR and DT. The highest Tg and Xc were achieved for 3/70/50 tape with values of 73°C and %22, respectively. Higher thermal stabilities and enhanced barrier properties were achieved after drawing, especially at the higher DR. Finally, tensile testing revealed simultaneous improvement in stiffness and toughness due to strain hardening for all the drawn tapes. The strength and elastic modulus were increased after increasing DR, DS, and DT and reached the highest values of 149 MPa and 3.6 GPa for 3/70/50. Overall, the properties were controllable by the processing conditions.

scholarly journals Formation of Stereocomplex Crystal and Its Effect on the Morphology and Property of PDLA/PLLA Blends

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2515
Author(s):  
Xiaolong Su ◽  
Lihua Feng ◽  
Demei Yu
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Polylactic Acid ◽  
Dielectric Spectroscopy ◽  
Degree Of Crystallinity ◽  
Cross Linking ◽  
Processing Conditions ◽  
Mass Ratio ◽  
Mechanism Of Formation ◽  
The Degree Of Crystallinity

Stereocomplex-polylactic acid (SC-PLA) is obtained in poly(d-lactic) acid/poly(l-lactic) acid (PDLA/PLLA) blends under adjusting processing conditions. It is found that the degree of crystallinity of overall SC-PLA is up to 43.7% in PDLA/PLLA blends of 1:1 mass ratio. Formation of stereocomplex (SC) crystals forces molecular chains in the blends to be more closely arranged and further enhances interaction between molecular chains, thus forming a physical cross-linking network in the SC crystals, resulting in the blends having a special microstructure. The mechanism of formation of the SC crystal physical cross-linking network is elucidated by dielectric spectroscopy, and the relationships between homocomplex (HC) crystals, SC crystals, and amorphous regions in the blends are also analyzed. Interestingly, mechanical properties of the blends are significantly improved due to formation of an SC crystal cross-linking network.

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