Interfacial improvements in cellulose nanofibers reinforced polylactide bionanocomposites prepared by in situ reactive extrusion

The shear-induced and cellulose-nanofiber nucleated crystallization of two novel aliphatic–aromatic copolyesters is outlined due to its significance for the in situ generation of biodegradable nanocomposites, which require the crystallization of nanofibrous sheared inclusions at higher temperatures. The shear-induced non-isothermal crystallization of two copolyesters, namely, poly(butylene adipate-co-succinate-co-glutarate-co-terephthalate) (PBASGT) and poly(butylene adipate-co-terephthalate) (PBAT), was studied following a light depolarization technique. To have a deep insight into the process, the effects of the shear rate, shear time, shearing temperature and cooling rate on the initiation, kinetics, growth and termination of crystals were investigated. Films of 60 μm were subjected to various shear rates (100–800 s−1) for different time intervals during cooling. The effects of the shearing time and increasing the shear rate were found to be an elevated crystallization temperature, increased nucleation density, reduced growth size of lamella stacks and decreased crystallization time. Due to the boosted nucleation sites, the nuclei impinged with each other quickly and growth was hindered. The effect of the cooling rate was more significant at lower shear rates. Shearing the samples at lower temperatures, but still above the nominal melting point, further shifted the non-isothermal crystallization to higher temperatures. As a result of cellulose nanofibers’ presence, the crystallization of PBAT, analyzed by DSC, was shifted to higher temperatures.

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In Situ Generation of Green Hybrid Nanofibrillar Polymer-Polymer Composites—A Novel Approach to the Triple Shape Memory Polymer Formation

Polymers ◽

10.3390/polym13121900 ◽

2021 ◽

Vol 13 (12) ◽

pp. 1900

Author(s):

Ramin Hosseinnezhad ◽

Iurii Vozniak ◽

Fahmi Zaïri

Keyword(s):

Polymer Blends ◽

Shape Memory ◽

Shape Memory Polymer ◽

Cellulose Nanofibers ◽

Polymeric Materials ◽

Novel Approach ◽

Phase Transition Temperatures ◽

Triple Shape Memory

The paper discusses the possibility of using in situ generated hybrid polymer-polymer nanocomposites as polymeric materials with triple shape memory, which, unlike conventional polymer blends with triple shape memory, are characterized by fully separated phase transition temperatures and strongest bonding between the polymer blends phase interfaces which are critical to the shape fixing and recovery. This was demonstrated using the three-component system polylactide/polybutylene adipateterephthalate/cellulose nanofibers (PLA/PBAT/CNFs). The role of in situ generated PBAT nanofibers and CNFs in the formation of efficient physical crosslinks at PLA-PBAT, PLA-CNF and PBAT-CNF interfaces and the effect of CNFs on the PBAT fibrillation and crystallization processes were elucidated. The in situ generated composites showed drastically higher values of strain recovery ratios, strain fixity ratios, faster recovery rate and better mechanical properties compared to the blend.

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Lignin-mediated in-situ synthesis of CuO nanoparticles on cellulose nanofibers: A potential wound dressing material

International Journal of Biological Macromolecules ◽

10.1016/j.ijbiomac.2021.01.050 ◽

2021 ◽

Vol 173 ◽

pp. 315-326 ◽

Cited By ~ 1

Author(s):

Md. Kaiser Haider ◽

Azeem Ullah ◽

Muhammad Nauman Sarwar ◽

Yusuke Saito ◽

Lei Sun ◽

...

Keyword(s):

Wound Dressing ◽

Cellulose Nanofibers ◽

In Situ Synthesis ◽

Cuo Nanoparticles

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Injectable and Gellable Chitosan Formulations Filled with Cellulose Nanofibers for Intervertebral Disc Tissue Engineering

Polymers ◽

10.3390/polym10111202 ◽

2018 ◽

Vol 10 (11) ◽

pp. 1202 ◽

Cited By ~ 18

Author(s):

Ingo Doench ◽

Maria Torres-Ramos ◽

Alexandra Montembault ◽

Paula Nunes de Oliveira ◽

Celia Halimi ◽

...

Keyword(s):

Intervertebral Disc ◽

Rheological Behavior ◽

Biomedical Application ◽

Flow Behavior ◽

Cellulose Nanofibers ◽

Nanofibrillated Cellulose ◽

The Body ◽

Mechanical Reinforcement ◽

Invasive Approach

The development of non-cellularized injectable suspensions of viscous chitosan (CHI) solutions (1.7–3.3% (w/w)), filled with cellulose nanofibers (CNF) (0.02–0.6% (w/w)) of the type nanofibrillated cellulose, was proposed for viscosupplementation of the intervertebral disc nucleus pulposus tissue. The achievement of CNF/CHI formulations which can gel in situ at the disc injection site constitutes a minimally-invasive approach to restore damaged/degenerated discs. We studied physico-chemical aspects of the sol and gel states of the CNF/CHI formulations, including the rheological behavior in relation to injectability (sol state) and fiber mechanical reinforcement (gel state). CNF-CHI interactions could be evidenced by a double flow behavior due to the relaxation of the CHI polymer chains and those interacting with the CNFs. At high shear rates resembling the injection conditions with needles commonly used in surgical treatments, both the reference CHI viscous solutions and those filled with CNFs exhibited similar rheological behavior. The neutralization of the flowing and weakly acidic CNF/CHI suspensions yielded composite hydrogels in which the nanofibers reinforced the CHI matrix. We performed evaluations in relation to the biomedical application, such as the effect of the intradiscal injection of the CNF/CHI formulation in pig and rabbit spine models on disc biomechanics. We showed that the injectable formulations became hydrogels in situ after intradiscal gelation, due to CHI neutralization occurring in contact with the body fluids. No leakage of the injectate through the injection canal was observed and the gelled formulation restored the disc height and loss of mechanical properties, which is commonly related to disc degeneration.

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Interfacial Improvements in a Green Biopolymer Alloy of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and Lignin via in Situ Reactive Extrusion

ACS Sustainable Chemistry & Engineering ◽

10.1021/acssuschemeng.6b00495 ◽

2016 ◽

Vol 4 (6) ◽

pp. 3465-3476 ◽

Cited By ~ 50

Author(s):

Shupin Luo ◽

Jinzhen Cao ◽

Armando G. McDonald

Keyword(s):

Reactive Extrusion

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Green Fabrication of Thermal-stable oxidized Cellulose Nanocrystals by Evolutive Fenton Reaction and In-Situ Nanoreinforced Thermoplastic Starch

10.21203/rs.3.rs-221425/v1 ◽

2021 ◽

Author(s):

Bingbing Gao ◽

Jiahui Yang ◽

Shuidong Zhang ◽

Xiangyu Li

Keyword(s):

Fenton Reaction ◽

Primary Alcohol ◽

Average Diameter ◽

Reactive Extrusion ◽

Thermoplastic Starch ◽

Degree Of Crystallinity ◽

Carboxyl Content ◽

In Situ Forming ◽

Interfacial Compatibility

Abstract High performances fiber and improved interfacial interaction can enhance the properties of polymer composites. Herein, microcrystalline cellulose (MCC) was oxidized by H2O2/CuSO4, a new Fenton process, to achieve oxidized MCC (OCNCs) with 16 ± 1% carboxyl content. Noteworthy, the thermal stability of OCNC was superior to CNC prepared by acid hydrolysis. Interestingly, the primary alcohol groups of MCC were selective oxidized and OCNCs achieved 11.0 nm, 231.6 nm and 72% of average diameter, length and degree of crystallinity, respectively. Then glycerol, starch and OCNCs were reactive extruded to fabricate TPS/OCNC bionanocomposites and their structure and performances were evaluated systematically. Strikingly, significant improvement in glass transition temperature (from 63.1 to 94.5 °C) and notch impact strength (from 1.3 to 3.9 kJ/m2) were noted for the amorphous TPS/OCNC with 1 wt% OCNC, and its tensile strength achieved 20.5 MPa, simultaneously. The improved mechanism of these performances was assigned to In-Situ forming “Carboxyl-Hydroxyl” hydrogen bonds which acted as the physically cross-linking interactions and improved the interfacial compatibility. We showcase Fenton reaction and reactive extrusion as the facile strategy to prepare sustainable and biodegradable TPS/OCNC bionanocomposites with properties more suitable for daily applications to replace petroleum-based plastic and eliminated the pollution of “microplastics.”

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Effects of Methylenediphenyl 4,4’-Diisocyanate and Maleic Anhydride as Coupling Agents on the Properties of Polylactic Acid/Polybutylene Succinate/Wood Flour Biocomposites by Reactive Extrusion

Materials ◽

10.3390/ma13071660 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1660

Author(s):

Young-Rok Seo ◽

Sang-U Bae ◽

Jaegyoung Gwon ◽

Qinglin Wu ◽

Birm-June Kim

Keyword(s):

Maleic Anhydride ◽

Polylactic Acid ◽

Viscoelastic Properties ◽

Interfacial Adhesion ◽

Wood Flour ◽

Flexural Modulus ◽

Reactive Extrusion ◽

Coupling Agents ◽

Polybutylene Succinate

Polylactic acid (PLA)/polybutylene succinate (PBS)/wood flour (WF) biocomposites were fabricated by in situ reactive extrusion with coupling agents. Methylenediphenyl 4,4’-diisocyanate (MDI) and maleic anhydride (MA) were used as coupling agents. To evaluate the effects of MDI and MA, various properties (i.e., interfacial adhesion, mechanical, thermal, and viscoelastic properties) were investigated. PLA/PBS/WF biocomposites without coupling agents revealed poor interfacial adhesion leading to deteriorated properties. However, the incorporation of MDI and/or MA into biocomposites showed high performances by increasing interfacial adhesion. For instance, the incorporation of MDI resulted in improved tensile, flexural, and impact strengths and an increase in tensile and flexural modulus was observed by the incorporation of MA. Specially, remarkably improved thermal stability was found in the PLA/PBS/WF biocomposites with 1 phr MDI and 1 phr MA. Also, the addition of MDI or MA into biocomposites increased the glass transition temperature and crystallinity, respectively. For viscoelastic property, the PLA/PBS/WF biocomposites with 1 phr MDI and 1 phr MA achieved significant enhancement in storage modulus compared to biocomposites without coupling agents. Therefore, the most balanced performances were evident in the PLA/PBS/WF biocomposites with the hybrid incorporation of small quantities of MDI and MA.

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