Highly toughened polylactide (PLA) nanocomposites with balanced stiffness and strength were successfully prepared by combining the modification of 5 wt% silica (SiO) nanoparticles and uniaxial pre-stretching. The PLA/5 wt% SiO nanocomposites fractured in a brittle way due to the network structure composed of cohesional entanglements. After pre-stretching, the elongation at break was increased to 168% at pre-stretching ratio (PSR) of only 0.5, which should be attributed to the destruction of the network structure of cohesional entanglements. With the increment of PSR, the modulus and tensile strength were improved obviously (2725 MPa, 101.6 MPa at PSR = 2.0) while the elongation at break (56% at PSR = 2.0) reduced gradually because of the formation of orientation and mesophase. However, the elongation at break was still larger than that of undrawn PLA (5.4%) and undrawn PLA nanocomposites (7.2%), indicating that the uniaxial pre-stretching was an effect way to strengthen and toughen PLA nanocomposites.
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http://dx.doi.org/10.1016/j.ijbiomac.2021.08.218 | DOI Listing |
Int J Biol Macromol
October 2024
Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China; School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China.
Sustainable poly (lactic acid) (PLA) with excellent strength, toughness, heat resistance, transparency, and biodegradability was achieved by uniaxial pre-stretching at 70 °C. The effect of pre-stretched ratio (PSR) on the microstructure and properties of the PLA was investigated. The undrawn PLA was brittle.
View Article and Find Full Text PDFFront Bioeng Biotechnol
July 2024
Laboratorio de Biomecánica y Biomateriales, Departamento de Ingeniería Mecánica, Universidad de Santiago de Chile, USACH, Santiago de Chile, Chile.
Gestation under chronic hypoxia causes pulmonary hypertension, cardiovascular remodeling, and increased aortic stiffness in the offspring. To mitigate the neonatal cardiovascular risk, pharmacological treatments (such as hemin and sildenafil) have been proposed to improve pulmonary vasodilation. However, little is known about the effects of these treatments on the aorta.
View Article and Find Full Text PDFCarbohydr Polym
July 2022
College of Chemistry and Molecular Sciences, Engineering Research Center of Natural Polymer-based Medical Materials in Hubei Province, Laboratory of Biomedical Polymers of Ministry of Education, Wuhan University, Wuhan 430072, China. Electronic address:
Considering that the poor mechanical performances of polysaccharide hydrogels always limit their practical applications, herein, we design and fabricate tough all-polysaccharide hydrogels by incorporating uniaxially/planarly oriented tunicate cellulose nanocrystals in physically cross-linked alginate networks. Firstly, alginate chains were loosely cross-linked by surface quaternized tunicate cellulose nanocrystals (Q-TCNCs) and Ca through electrostatic interaction. Secondly, the loosely cross-linked hydrogel was pre-stretched and immersed into CaCl solution, obtaining uniaxially oriented hydrogel, whose tensile strength was 31.
View Article and Find Full Text PDFPolymers (Basel)
February 2022
School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
shaped poly(methyl methacrylate) (PMMA) samples were pre-stretched at different temperatures (within the glass transition range and slightly above) to different strains. Subsequently, these pre-stretched samples were aged at 40 °C for up to three months, and finally, all samples were uniaxially stretched to fracture. The Young's modulus, ultimate stress and toughness of the samples were obtained and plotted as a function of the temperature, and strain in pre-stretching in the contour format.
View Article and Find Full Text PDFInt J Biol Macromol
November 2021
Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
Highly toughened polylactide (PLA) nanocomposites with balanced stiffness and strength were successfully prepared by combining the modification of 5 wt% silica (SiO) nanoparticles and uniaxial pre-stretching. The PLA/5 wt% SiO nanocomposites fractured in a brittle way due to the network structure composed of cohesional entanglements. After pre-stretching, the elongation at break was increased to 168% at pre-stretching ratio (PSR) of only 0.
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