Study of the Influence of the Almond Shell Variety on the Mechanical Properties of Starch-Based Polymer Biocomposites

This article is focused on the development of a series of biodegradable and eco-friendly biocomposites based on starch polymer (Mater-Bi DI01A) filled with 30 wt% almond shell (AS) of different varieties (Desmayo Rojo, Largueta, Marcona, Mollar, and a commercial mixture of varieties) to study the influence of almond variety in the properties of injected biodegradable parts. The different AS varieties are analysed by means of Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD). The biocomposites are prepared in a twin-screw extruder and characterized in terms of their mechanical (tensile, flexural, Charpy impact, and hardness tests) and thermal properties (differential scanning calorimetry (DSC) and TGA). Despite observing differences in the chemical composition of the individual varieties with respect to the commercial mixture, the results obtained from the mechanical characterisation of the biocomposites do not present significant differences between the diverse varieties used. From these results, it was concluded that the most recommended option is to work with the commercial mixture of almond shell varieties, as it is easier and cheaper to acquire.

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Recyclability Analysis of Starch Thermoplastic/Almond Shell Biocomposite

Polymers ◽

10.3390/polym13071159 ◽

2021 ◽

Vol 13 (7) ◽

pp. 1159

Author(s):

Ana Ibáñez-García ◽

Asunción Martínez-García ◽

Santiago Ferrándiz-Bou

Keyword(s):

Linseed Oil ◽

Charpy Impact ◽

Melt Flow Index ◽

Flow Index ◽

Almond Shell ◽

Scanning Calorimetry ◽

Twin Screw ◽

Visual Properties ◽

Shell Powder ◽

Do So

This article is focused on studying the effect of the reprocessing cycles on the mechanical, thermal, and aesthetic properties of a biocomposite. This process is based on starch thermoplastic polymer (TPS) filled with 20 wt% almond shell powder (ASP) and epoxidized linseed oil (ELO) as a compatibilizing additive. To do so, the biocomposite was prepared in a twin-screw extruder, molded by injection, and characterized in terms of its mechanical, thermal, and visual properties (according to CieLab) and the melt flow index (MFI). The analyses carried out were tensile, flexural, Charpy impact tests, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). The effects of the reprocessing were also studied for the biodegradable unfilled TPS polymer. The results showed that TPS and TPS/ASP biocomposite suffer changes progressively on the properties studied after each reprocessing cycle. Furthermore, it was observed that the addition of ASP intensified these effects regarding TPS. However, in spite of the progressive degradation in both cases, it is technically feasible to reprocess the material at least three times without needing to incorporate virgin material.

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High-Tribological-Performance Polymer Nanocomposites: An Approach Based on the Superlubricity State of the Graphene Oxide Agglomerates

Polymers ◽

10.3390/polym13142237 ◽

2021 ◽

Vol 13 (14) ◽

pp. 2237

Author(s):

Eder H. C. Ferreira ◽

Angela Aparecida Vieira ◽

Lúcia Vieira ◽

Guilhermino J. M. Fechine

Keyword(s):

Graphene Oxide ◽

High Viscosity ◽

Tribological Performance ◽

Multilayer Graphene ◽

High Concentration ◽

Scanning Calorimetry ◽

Mechanical Reinforcement ◽

Transmission Electron ◽

Twin Screw ◽

Mechanical Tensile

Here, nanocomposites of high-molecular-weight polyethylene (HMWPE) and HMWPE-UHMWPE (80/20 wt.%) containing a low amount of multilayer graphene oxide (mGO) (≤0.1 wt.%) were produced via twin-screw extrusion to produce materials with a higher tribological performance than UHMWPE. Due to the high viscosity of both polymers, the nanocomposites presented a significant concentration of agglomerates. However, the mechanical (tensile) and tribological (volumetric loss) performances of the nanocomposites were superior to those of UHMWPE. The morphology of the nanocomposites was investigated using differential scanning calorimetry (DSC), microtomography, and transmission electron microscopy (TEM). The explanation for these results is based on the superlubricity phenomenon of mGO agglomerates. It was also shown that the well-exfoliated mGO also contained in the nanocomposite was of fundamental importance as a mechanical reinforcement for the polymer. Even with a high concentration of agglomerates, the nanocomposites displayed tribological properties superior to UHMWPE’s (wear resistance up to 27% higher and friction coefficient up to 57% lower). Therefore, this manuscript brings a new exception to the rule, showing that agglomerates can act in a beneficial way to the mechanical properties of polymers, as long as the superlubricity phenomenon is present in the agglomerates contained in the polymer.

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Liquid crystalline polyureas with oligo(ethylene glycol) sequences

e-Polymers ◽

10.1515/epoly.2010.10.1.1425 ◽

2010 ◽

Vol 10 (1) ◽

Author(s):

Shahram Mehdipour-Ataei ◽

Leila Akbarian-Feizi

Keyword(s):

Liquid Crystalline ◽

Spectroscopic Method ◽

Polymerization Reaction ◽

X Ray Diffraction ◽

Subsequent Reaction ◽

Scanning Calorimetry ◽

Polar Solvents ◽

X Ray ◽

H Nmr ◽

Ft Ir

AbstractA diamine monomer containing ester, amide and ether functional groups was prepared and its polymerization reaction with different diisocyanates to give main chain poly(ester amide ether urea)s was investigated. The monomer was synthesized via reaction of terephthaloyl chloride with 4-hydroxybenzoic acid and subsequent reaction of the resulted diacid with 1,8-diamino-3,6-dioxaoctane. The polymers were characterized by FT-IR and 1H-NMR spectroscopic method and elemental analysis. The resulting polymers exhibited excellent solubility in polar solvents. Crystallinity of the resulted polymers was evaluated by wide-angle X-ray diffraction (WXRD) method, and they exhibited semi-crystalline patterns. The glass transition temperatures (Tg) of the polymers determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were in the range of 88-112 °C. The temperatures for 10% weight loss (T10) from their thermogravimetric analysis (TGA) curves were found to be in the range of 297-312 °C in air. Also the prepared polyureas showed liquid crystalline character.

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Synthesis and Properties of Thermotropic Liquid Crystalline Polyesters with Flexible Polymethylene Spacer

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.428-429.126 ◽

2010 ◽

Vol 428-429 ◽

pp. 126-131

Author(s):

Wei Zhong Lu ◽

Chun Wei ◽

Qui Shan Gao

Keyword(s):

Optical Microscopy ◽

Liquid Crystalline ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

X Ray ◽

Structure Morphology ◽

Temperature Ranges ◽

Ft Ir ◽

Diffraction Peaks ◽

Ubbelohde Viscometer

Polymethylene bis(p-hydroxybenzoates) were prepared from methyl p-hydroxybenzoate and different diols by melted transesterification reaction. Three liquid crystalline polyesters were synthesized from terephthaloyl dichloride and polymethylene bis(p-hydroxybenzoates). Its structure, morphology and properties were characterized by Ubbelohde viscometer, Fourier transform infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC), polarized optical microscopy (POM) with a hot stage, and wide-angle X-ray diffraction (WAXD). Results indicated that the intrinsic viscosities were between 0.088 and 0.210 dL/g. Optical microscopy showed that the TLCP has a highly threaded liquid crystalline texture and a high birefringent schlieren texture character of nematic phase and has wider mesophase temperature ranges for all polyesters. DSC analysis were found that the melting point (Tm), isotropic temperature (Ti) of TLCPs decreased and the temperature range of the liquid crystalline phase became wider with increased number of methylene spacers in the polyester. The WAXD results showed that TLCPs owned two strong diffraction peaks at 2θ near 19° and 23°.

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SOLID-STATE PROPERTIES AND SOLUBILITY STUDIES OF NOVEL PHARMACEUTICAL COCRYSTAL OF ITRACONAZOLE

International Journal of Applied Pharmaceutics ◽

10.22159/ijap.2018v10i5.26663 ◽

2018 ◽

Vol 10 (5) ◽

pp. 97

Author(s):

Stevanus Hiendrawan ◽

Bambang Veriansyah ◽

Raymond R. Tjandrawinata

Keyword(s):

Sebacic Acid ◽

Aqueous Solubility ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Solution Ph ◽

Pharmaceutical Ingredients ◽

Naphthoic Acid ◽

Pharmaceutical Cocrystal ◽

Solvent Evaporation Process ◽

The Individual

Objective: Pharmaceutical cocrystal is a promising method to improve the solubility of active pharmaceutical ingredients (APIs). Itraconazole (ITZ) is a BCS class II antifungal drug with poor aqueous solubility, therefore an attempt was made to improve the solubility of ITZ using cocrystallization technique. In this work, six novel pharmaceutical cocrystals of ITZ with various coformers, including 4-hydroxybenzoic acid (4HBA), trans-cinnamic acid (TCA), suberic acid (SUB), sebacic acid (SBC), 1-hydroxy-2-naphthoic acid (1H2N), and benzamide (BZD) were prepared.Methods: ITZ cocrystals was prepared by solvent evaporation process. The cocrystals produced were characterized using powder x-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and fourier transform infrared (FTIR) spectroscopy. Solubility analysis was performed to evaluate the cocrystals.Results: PXRD and DSC analysis revealed that the pattern of all ITZ cocrystals was distinguishable from the individual compounds which indicates the formation of new phase. The solubility of ITZ and its cocrystals from highest to lowest after 24 h in 0.1 N HCl solution (pH 1.2) follows the order ITZ-TCA (1.97-fold), ITZ-SBC (1.09-fold), ITZ, ITZ-1H2N (0.58-fold) and ITZ-4HBA (0.46-fold).Conclusion: This study demonstrates that the selection of coformers has pronounced an impact on the physicochemical properties of ITZ. Based on this study, it can be concluded that cocrystallization offers a valuable way to improve the solubility of ITZ.

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Compatibility between Magnesium Stearate and Pharmaceutical Acidic Active Compounds/Excipients with DSC

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.856.190 ◽

2020 ◽

Vol 856 ◽

pp. 190-197

Author(s):

Pornsit Chaiya ◽

Thawatchai Phaechamud

Keyword(s):

Differential Scanning Calorimetry ◽

Magnesium Stearate ◽

X Ray Diffraction ◽

Salt Form ◽

Scanning Calorimetry ◽

Powder Mixtures ◽

X Ray ◽

Pharmaceutical Excipients ◽

Drug Compounds ◽

Ft Ir

Compatibility investigation was performed between magnesium stearate and acidic drug compounds (ibuprofen, indomethacin and valproic acid) and acidic pharmaceutical excipients (lactic acid and citric acid) using differential scanning calorimetry (DSC). DSC study indicated the possible incompatibility for the mixture between magnesium stearate and any compounds. Alteration in DSC thermogram was found in all mixtures. The eutectic phenomenon was found in the powder mixture of magnesium stearate and ibuprofen. In addition, the presence of melting endothermic peak of stearic acid in other powder mixtures except the mixture of magnesium stearate and indomethacin indicating breakage of salt form of magnesium stearate. This alteration could relate to the influence on physicochemical properties of drug compounds and pharmaceutical excipients which powder x-ray diffraction (PXRD) and Fourier Transform Infrared Spectroscopy (FT-IR) should be further analyzed to confirm the interactions between compounds.

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Stress-Induced Crystal-to-Crystal Transformations in High-Density Polyethylene-Layered Silicate Nanocomposites: A Spectroscopic Study

Applied Spectroscopy ◽

10.1366/0003702055012519 ◽

2005 ◽

Vol 59 (9) ◽

pp. 1148-1154 ◽

Cited By ~ 6

Author(s):

Spiros Tzavalas ◽

Vasilis G. Gregoriou

Keyword(s):

High Density Polyethylene ◽

Mechanical Strain ◽

Layered Silicate ◽

High Density ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Polyethylene Matrix ◽

Dsc Measurements ◽

Infrared Measurements ◽

Ft Ir

High-density polyethylene (HDPE)–clay nanocomposites have been prepared using the melt intercalation technique. Organically modified montmorillonite at various loadings (0.5–7%) was used as a nanoadditive. Fourier transform infrared spectroscopy (FT-IR) was utilized for the first time to monitor the stress-induced crystal-to-crystal transformations of the polyethylene matrix with respect to the clay loading as well as to the degree of mechanical strain. In addition, polarized infrared measurements revealed information on both the orientation and the stress-induced distortion of the crystals. It was concluded that the crystal-to-crystal transformations are hindered by the presence of the clay, which also prevented the crystals from orienting even at low clay loadings (1%). Finally, X-ray diffraction (XRD) and differential scanning calorimetry (DSC) measurements confirmed the presence of the stress-induced crystalline structures in agreement with the infrared measurements.

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Preparation and Properties of Ginger Essential Oil β-Cyclodextrin/Chitosan Inclusion Complexes

Coatings ◽

10.3390/coatings8090305 ◽

2018 ◽

Vol 8 (9) ◽

pp. 305 ◽

Cited By ~ 9

Author(s):

Yan Zhang ◽

Hui Zhang ◽

Fang Wang ◽

Li-Xia Wang

Keyword(s):

Particle Size ◽

Essential Oil ◽

Spray Drying ◽

Small Particle Size ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

X Ray ◽

Ft Ir ◽

Thermal Stability Of ◽

Scanning Electron

The ginger essential oil/β-cyclodextrin (GEO/β-CD) composite, ginger essential oil/β-cyclodextrin/chitosan (GEO/β-CD/CTS) particles and ginger essential oil/β-cyclodextrin/chitosan (GEO/β-CD/CTS) microsphere were prepared with the methods of inclusion, ionic gelation and spray drying. Their properties were studied by using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermo-gravimetry analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). The results showed that the particle size of GEO/β-CD composite was smaller than that of β-CD and GEO/β-CD/CTS particles were loose and porous, while the microsphere obtained by spray drying had certain cohesiveness and small particle size. Besides, results also indicated that β-CD/CTS could modify properties and improve the thermal stability of GEO, which would improve its application value in food and medical industries.

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Structures and physicochemical properties of vortioxetine salts

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520616010556 ◽

2016 ◽

Vol 72 (5) ◽

pp. 723-732 ◽

Cited By ~ 6

Author(s):

Xinbo Zhou ◽

Xiurong Hu ◽

Suxiang Wu ◽

Jiali Ye ◽

Mengying Sun ◽

...

Keyword(s):

Antidepressant Drug ◽

Drug Candidate ◽

X Ray Diffraction ◽

High Solubility ◽

Scanning Calorimetry ◽

Intrinsic Dissolution ◽

X Ray ◽

Acidic Proton ◽

Water Ph ◽

Ft Ir

In the present work, novel salts of the multimodal antidepressant drug vortioxetine (VT) were crystallized with pharmaceutically acceptable acids, aiming to improve the solubility of VT. The acids for VT were selected based on ΔpKabeing greater than 2 or 3. Salts of hydrobromic acid (HBr), hydrochloric acid (HCl),p-hydroxybenzoic acid (PHBA), saccharin (SAC) and L-aspartic acid (ASP) were reported. All salts were characterized by single-crystal X-ray diffraction, FT–IR, powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC). The acidic proton is transferred to the secondary N atom on the piperazine ring of VT, forming the charge-assisted hydrogen bond N+—H...X−(X= Cl, Br, O). Solubility and intrinsic dissolution rate (IDR) experiments were carried out in distilled water (pH = 7.0) to compare the solubilities of the salts with that of VT. The VT–ASP–H2O (1:1:2) salt showed 414 times higher solubility and 1722 times faster IDR compared with VT. VT–ASP–H2O (1:1:2) is a high solubility salt that is stable in a slurry experiment at 298 K in 95% ethanol. The experimental data for the VT–ASP–H2O (1:1:2) salt identify it as a promising drug candidate.

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Tuning of HDPE Properties for 3D Printing

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.773.67 ◽

2018 ◽

Vol 773 ◽

pp. 67-71 ◽

Cited By ~ 3

Author(s):

Paweesinee Chatkunakasem ◽

Panisa Luangjuntawong ◽

Aphiwat Pongwisuthiruchte ◽

Chuanchom Aumnate ◽

Pranut Potiyaraj

Keyword(s):

3D Printing ◽

Melt Flow Index ◽

Flow Index ◽

Melt Blending ◽

X Ray Diffraction ◽

Screw Extruder ◽

Scanning Calorimetry ◽

Crystalline Polymers ◽

Twin Screw ◽

Low Crystalline

The objective of this study is to improve high density polyethylene (HDPE) properties for 3D printing by addition of graphene and low density polyethylene (LDPE). Graphene was prepared by modified Hummer’s method. The prepared graphene was characterized by the infrared spectroscopy and the X-ray diffraction analysis (XRD). Graphene/HDPE and LDPE/HDPE composites were successfully prepared through the melt-blending technique using a twin-screw extruder. The melt flow index (MFI) and differential scanning calorimetry (DSC) were employed to characterize neat HDPE and the modified HDPE. FTIR and XRD results show that graphite was successfully changed into graphene completely and MFI of graphene/HDPE and LDPE/HDPE decreased as the amount of graphene and LDPE in the composite blends increased. DSC results show that the addition of low crystalline polymers can reduce a crystallization temperature and crystallinity content.

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