scholarly journals Biocomposites of Bio-Polyethylene Reinforced with a Hydrothermal-Alkaline Sugarcane Bagasse Pulp and Coupled with a Bio-Based Compatibilizer

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2158
Author(s):  
Nanci Vanesa Ehman ◽  
Diana Ita-Nagy ◽  
Fernando Esteban Felissia ◽  
María Evangelina Vallejos ◽  
Isabel Quispe ◽  
...  

Bio-polyethylene (BioPE, derived from sugarcane), sugarcane bagasse pulp, and two compatibilizers (fossil and bio-based), were used to manufacture biocomposite filaments for 3D printing. Biocomposite filaments were manufactured and characterized in detail, including measurement of water absorption, mechanical properties, thermal stability and decomposition temperature (thermo-gravimetric analysis (TGA)). Differential scanning calorimetry (DSC) was performed to measure the glass transition temperature (Tg). Scanning electron microscopy (SEM) was applied to assess the fracture area of the filaments after mechanical testing. Increases of up to 10% in water absorption were measured for the samples with 40 wt% fibers and the fossil compatibilizer. The mechanical properties were improved by increasing the fraction of bagasse fibers from 0% to 20% and 40%. The suitability of the biocomposite filaments was tested for 3D printing, and some shapes were printed as demonstrators. Importantly, in a cradle-to-gate life cycle analysis of the biocomposites, we demonstrated that replacing fossil compatibilizer with a bio-based compatibilizer contributes to a reduction in CO2-eq emissions, and an increase in CO2 capture, achieving a CO2-eq storage of 2.12 kg CO2 eq/kg for the biocomposite containing 40% bagasse fibers and 6% bio-based compatibilizer.

Author(s):  
Reza R. Rizvi ◽  
Jae K. Kim ◽  
Hani E. Naguib

This paper investigates the processing and its effects and the effect of multiwall carbon nanotube (MWNT) composition on the thermal, electrical and mechanical properties of polylactide (PLA)-MWNT composites. The composite films were prepared by a solvent casting process using two solvents, chloroform and 1,4-dioxane. The dispersion of the MWNTs in PLA was examined using a scanning electron microscope and was found to be more improved when 1,4-dioxane was used as the solvent as compared to chloroform. The thermal characteristics of the composites were examined on Differential Scanning Calorimetry and Thermo-gravimetric Analysis. Composites prepared using 1,4-dioxane had greater improvements in composite decomposition temperature, glass transition temperature and displayed faster crystallization kinetics. The mechanical properties of the composites were tested in uniaxial tension. Composites prepared using chloroform had a lower modulus than composites prepared using 1,4-dioxane. The electrical AC conductivity of the composites was measured over a broad frequency spectrum. Composites prepared using 1,4-dioxane displayed electrical percolation at 0.5 wt.% MWNT in PLA while percolation was absent in 0.5 wt.% MWNT composites prepared using chloroform.


2021 ◽  
pp. 1-8
Author(s):  
Ching-Cheng Huang

BACKGROUND: The biologic scaffolds derived from decellularized tissues and organs have been successfully developed in a variety of preclinical and/or clinical studies. OBJECTIVE: The new decellularized liver-regenerative 3D printing biomaterials were designed and prepared for cell-based liver therapies. METHODS: An extraction process was employed to remove the tissue and cellular molecules from porcine liver via pretreatment of supercritical fluid of carbon dioxide (ScCO2). Varying porosities of the decellularized liver tissues were created using papain-containing reagent treatments after ScCO2. RESULTS: The resulting liver-regenerative 3D printing biomaterials of decellularized liver collagen scaffolds were characterized by Fourier transform infrared spectroscopy, thermo-gravimetric analysis, differential scanning calorimetry and scanning electron microscopy. CONCLUSIONS: The decellularized liver collagen scaffolds with good thermal stability (>150 °C) were obtained and employed as liver-regenerative 3D printing biomaterials for cell-based liver therapies.


Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3006 ◽  
Author(s):  
Mihaela Tanase-Opedal ◽  
Eduardo Espinosa ◽  
Alejandro Rodríguez ◽  
Gary Chinga-Carrasco

Biopolymers from forestry biomass are promising for the sustainable development of new biobased materials. As such, lignin and fiber-based biocomposites are plausible renewable alternatives to petrochemical-based products. In this study, we have obtained lignin from Spruce biomass through a soda pulping process. The lignin was used for manufacturing biocomposite filaments containing 20% and 40% lignin and using polylactic acid (PLA) as matrix material. Dogbones for mechanical testing were 3D printed by fused deposition modelling. The lignin and the corresponding biocomposites were characterized in detail, including thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction analysis (XRD), antioxidant capacity, mechanical properties, and scanning electron microscopy (SEM). Although lignin led to a reduction of the tensile strength and modulus, the reduction could be counteracted to some extent by adjusting the 3D printing temperature. The results showed that lignin acted as a nucleating agent and thus led to further crystallization of PLA. The radical scavenging activity of the biocomposites increased to roughly 50% antioxidant potential/cm2, for the biocomposite containing 40 wt % lignin. The results demonstrate the potential of lignin as a component in biocomposite materials, which we show are adequate for 3D printing operations.


2018 ◽  
Vol 5 (3) ◽  
pp. 171686 ◽  
Author(s):  
Xiaoxiao Zhang ◽  
Tingyuan Gong ◽  
Hong Chi ◽  
Tianduo Li

Size control has been successfully achieved in inorganic materials, but it remains a challenge in polymer nanomaterials due to their polydispersity. Here, we report a facile approach to tailor the diameters of polyurethane (PU) nanoparticles (490 nm, 820 nm and 2.1 µm) via perylene bisimide (PBI) assisted self-assembly. The formed morphologies such as spindle, spherical and core–shell structures depend on the ratio of PBI and polymer concentrations. It is shown that the formation of PU nanoparticles is directed by π–π stacking of PBI and the morphology transition is not only affected by the amount of PBI incorporated, but also influenced by solvent, which controls the initial evaporation balance. Furthermore, the prepared PUs exhibit retained optical stability and enhanced thermal stability. The PUs, designed to have conjugated PBI segments in backbones, were synthesized via ring-opening and condensation reactions. Compared with the neat PU, gel permeation chromatography shows narrower molecular weight distribution. Fluorescence spectra and ultraviolet–visible spectra indicate retained maximum emission wavelength of PBI at 574 nm and 5.2% quantum yields. Thermo-gravimetric analysis and differential scanning calorimetry reveal 79°C higher decomposition temperature and 22°C higher glass transition temperature. This study provides a new way to fabricate well-defined nanostructures of functionalized PUs.


2020 ◽  
Vol 4 (1) ◽  
pp. 17-27
Author(s):  
Nasir Abbas ◽  
Nadia Qamar ◽  
Amjad Hussain ◽  
Sumera Latif ◽  
Muhammad Sohail Arshad ◽  
...  

Aim: The aim of the present work was to fabricate customized tablets of ciprofloxacin hydrochloride through 3D printing for optimized dosing. Materials & methods: A hot melt extrusion technique was employed to produce polyvinyl alcohol filaments with differing strengths of ciprofloxacin hydrochloride. Drug-loaded filaments were characterized for mechanical strength, thermal behavior and structural characteristics prior to printing of tablets by varying the infill percentage. Final formulations were evaluated for drug release profiles. Results: The prepared formulations contained 15–20% drug. The drug release patterns of different formulations were found to be reliant on infill percentage. Differential scanning calorimetry and thermo-gravimetric analysis confirmed that degradation temperature of drug is way above the printing temperature. Conclusion: This work is potentially significant for optimized antibiotic dosing, which in turn leads to enhanced clinical outcome.


Author(s):  
Abdel-Hamid I. Mourad ◽  
Omar G. Ayad ◽  
Ashfakur Rahman ◽  
Ali Hilal-Alnaqbi ◽  
Basim I. Abu-Jdayil

This work is concerned with the synthesis and characterization of Multi-Walled Carbon Nanotube (MWCNT) reinforced Kevlar KM2Plus composites with various MWCNT contents (0.2, 0.3, 0.4, 0.5, 0.6, and 0.8 wt. %), by the wet lay-up technique. These samples were experimentally investigated for their thermo-mechanical properties using Thermo-Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), tensile testing and three-point bending techniques. The mechanical properties showed remarkable improvement with increasing MWCNT wt.% up to certain content. The results revealed that the addition of MWCNT fillers has no significant effect on the thermal stability of the composites.


2011 ◽  
Vol 284-286 ◽  
pp. 1894-1900
Author(s):  
Kai Feng Li ◽  
Peng Fu ◽  
Chuan Lin Liu ◽  
Qing Xiang Zhao ◽  
Min Ying Liu

A kind of semi-aromatic polyamide, poly(dodecamethylene terephthalamide) (PA12T) was synthesized via a three-step reaction of terephthalic acid and 1,12-dodecanediamine. The structure of the prepared PA12T was characterized by Fourier transform infrared (FT-IR) spectroscopy and proton nuclear magnetic resonance (1H-NMR). The thermal behaviour of PA12T was determined by differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA) and dynamic mechanical analysis (DMA). Melting temperature (Tm), glass transition temperature (Tg) and decomposition temperature (Td) of PA12T are 311°C, 144°C and 429°C, respectively. Isothermal crystallization kinetics of PA12T have been investigated in the temperature range of 270-280°C using DSC. The activation energies (ΔE) were determined to be -170.4 kJ/mol for the isothermal crystallization processes by the Arrhenius’ methods.


2009 ◽  
Vol 28 (3) ◽  
pp. 179-191 ◽  
Author(s):  
Imelda Olivas-Armendariz ◽  
Perla E. García-Casillas ◽  
Alberto Martínez-Villafañe ◽  
Carlos A. Martinez-Pérez

In this work the synthesis and characterization of polyurethane (PU)-chitosan(CH) porous prepared by thermal induced phase separation (TIPS) is described, the obtained products were characterized by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC), evidence of the interaction between both polymers was acquired from infrared spectroscopy. The morphology of the scaffolds was studied by scanning electron microscopy also the mechanical properties were acquired. The results showed that the TIPS technique is appropriate for the production of PU-CH porous materials.


2013 ◽  
Vol 785-786 ◽  
pp. 714-717 ◽  
Author(s):  
Yi Zhou ◽  
Yong Zhu Cui ◽  
Guo Jun Liu ◽  
Li Hua Lv

An intumescent flame retardant (IFR) containing phosphorus and APP was applied to polyester fabric. The finishing process was optimized and the properties of treated fabric were characterized. The optimum process was as follows: the total dosage of IFR system was 40%, the mass ratio of phosphorus-containing flame retardants and APP was 7:3, and curing temperature was 180°C. The treated PET fabrics imparted good resistance to melt drop. Characterization of the thermo-gravimetric analysis, differential scanning calorimetry (DSC) indicated that much more residual char with intumescent structure, the incombustible gas and water were formed during combustion of flame retardant polyester fabric, whose decomposition temperature was lower compared to that of the untreated sample.


2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Huashan Yang ◽  
Yujun Che

The agglomeration of nano-CaCO3 (NC) is the largest bottleneck in applications in cementitious materials. If nano-CaCO3 modifies the surface of micron-scale limestone powder (LS), then it will form nano-CaCO3/limestone composite particles (NC/LS). It is known that micron-scale limestone is easily dispersed, and the “dispersion” of NC is governed by that of LS. Therefore, the dispersion of nano-CaCO3 can be improved by the NC/LS in cementitious materials. In this work, the preparation of NC/LS was carried out in a three-necked flask using the Ca(OH)2-H2O-CO2 reaction system. The morphology of NC/LS was observed by a field emission scanning electron microscope (FE-SEM). The effects of NC/LS on the hydration products and pore structure of cementitious materials are proposed. 5% NC/LS was added into cement paste and mortar, and the mechanical properties of the specimens were measured at a certain age. Differential scanning calorimetry (DSC), thermal gravimetric analysis (TG), and backscattered electron imaging (BSE) were conducted on the specimens to investigate the hydration products and pore structure. The properties of specimens with NC/LS were compared to that of control specimens (without NC/LS). The results revealed that NC/LS reduced the porosity and improved the mechanical properties of the cementitious materials.


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