Electrospun hyperbranched polylactic acid–modified cellulose nanocrystals/polylactic acid for shape memory membranes with high mechanical properties

2019 ◽  
Vol 31 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Qingyuan Peng ◽  
Jingzhen Cheng ◽  
Shaorong Lu ◽  
Yuqi Li
Keyword(s):  
Mechanical Properties ◽  
Shape Memory ◽  
Polylactic Acid ◽  
Cellulose Nanocrystals ◽  
Modified Cellulose

scholarly journals Mechanical and Optical Properties of Polylactic Acid Films Containing Surfactant-Modified Cellulose Nanocrystals

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Jose Luis Orellana ◽  
Derek Wichhart ◽  
Christopher L. Kitchens
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Optical Properties ◽  
Polylactic Acid ◽  
Cellulose Nanocrystals ◽  
Cetyltrimethylammonium Bromide ◽  
Polymeric Matrices ◽  
Nanoscale Structure ◽  
Surface Modified ◽  
Modified Cellulose

The addition of surface-modified cellulose nanocrystals (CNCs) to polymeric matrices can lead to an enhancement of the mechanical and optical properties of host polymers. The use of surfactants can provide an easy and effective way to change the CNC functionality and to evaluate the effects of surface chemistry in the reinforcement mechanisms. In this work, CNCs were solution blended with polylactic acid (PLA) and melt extruded into films. The PLA toughness increased from 1.70 MJ/m3to 2.74 MJ/m3, a 61% increase, with the addition of 1% of decylamine-modified CNCs without a decrease of the tensile strength or modulus. In this work, we investigated the use of two surfactants, decylamine and cetyltrimethylammonium bromide, to enhance CNC compatibility with the hydrophobic PLA matrix. Decylamine at 1.0 wt.% with respect to CNC loading was found to significantly enhance CNC compatibility and property enhancement. The low concentration of surfactant is notable, as other works typically use significantly higher loadings for CNC incorporation and property enhancement. At high CNC concentrations, mechanical properties decreased but the aligned assembly of the CNCs provided intricate colors to the films when observed between crossed polars. The alignment and nanoscale structure of CNCs within the films play an important role in the properties obtained.

scholarly journals Effect of GNPs on the Piezoresistive, Electrical and Mechanical Properties of PHA and PLA Films

Fibers ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 86
Author(s):  
Gonzalo Mármol ◽  
Usha Kiran Sanivada ◽  
Raul Fangueiro
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Polyethylene Glycol ◽  
Polylactic Acid ◽  
Cellulose Nanocrystals ◽  
Graphene Nanoplatelets ◽  
Gauge Factor ◽  
Solvent Casting ◽  
Nanoparticle Distribution ◽  
Primary Focus

Sustainability has become the primary focus for researchers lately. Biopolymers such as polyhydroxyalkanoate (PHA) and polylactic acid (PLA) are biocompatible and biodegradable. Introducing piezoresistive response in the films produced by PLA and PHA by adding nanoparticles can be interesting. Hence, a study was performed to evaluate the mechanical, electrical and piezoresistive response of films made from PHA and PLA. The films were produced by solvent casting, and they were reinforced with graphene nanoplatelets (GNPs) at different nanoparticle concentrations (from 0.15 to 15 wt.%). Moreover, cellulose nanocrystals (CNC) as reinforcing elements and polyethylene glycol (PEG) as plasticizers were added. After the assessment of the nanoparticle distribution, the films were subjected to tests such as tensile, electrical conductivity and piezoresistive response. The dispersion was found to be good in PLA films and there exist some agglomerations in PHA films. The results suggested that the incorporation of GNPs enhanced the mechanical properties until 0.75 wt.% and they reduced thereon. The addition of 1% CNCs and 20% PEG in 15 wt.% GNPs’ tensile values deteriorated further. The PHA films showed better electrical conductivity compared to the PLA films for the same GNPs wt.%. Gauge factor (GF) values of 6.30 and 4.31 were obtained for PHA and PLA, respectively.

scholarly journals Surface Modification of Cellulose Nanocrystals with Lactone Monomers via Plasma-Induced Polymerization and Their Application in ABS Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2699
Author(s):  
Ramón Díaz de León ◽  
Ediberto Guzmán ◽  
Ricardo López González ◽  
Alejandro Díaz Elizondo ◽  
Ilse Magaña ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Yield Stress ◽  
Cellulose Nanocrystals ◽  
Polymeric Materials ◽  
Environmental Problems ◽  
Plasma Power ◽  
Polymeric Matrices ◽  
Promising Application ◽  
Modified Cellulose

The growing concern for environmental problems has motivated the use of materials obtained from bio-based resources such as cellulose nanocrystals which have a promising application acting as fillers or reinforcements of polymeric materials. In this context, in this article, plasma-induced polymerization is proposed as a strategy to modify nanocrystals at different plasma power intensities using ε-caprolactone and δ-decalactone to improve their compatibility with polymeric matrices. The characterization was carried out using techniques such as FTIR, TGA, XRD, XPS, and AFM, with which a successful functionalization was demonstrated without altering the inherent properties of the nanocrystals. The preparation of ABS nanocomposites was carried out with the modified nanoparticles and the evaluation of the mechanical properties indicates an increase in Young’s modulus and yield stress under certain concentrations of modified cellulose nanocrystals.

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