scholarly journals Plastic Bottle Cap Recycling—Characterization of Recyclate Composition and Opportunities for Design for Circularity

2020 ◽  
Vol 12 (24) ◽  
pp. 10378
Author(s):  
Markus Gall ◽  
Andrea Schweighuber ◽  
Wolfgang Buchberger ◽  
Reinhold W. Lang
Keyword(s):  
High Performance ◽  
Regulatory Requirements ◽  
Scanning Calorimetry ◽  
Comprehensive Strategy ◽  
Polymer Resin ◽  
Plastic Bottle ◽  
Use Phase ◽  
Slip Agent ◽  
Beverage Packaging

In line with efforts to create a circular economy of plastics, recent EU legislation is strengthening plastic bottle recycling by ambitious separate collection targets and mandatory recycled content obligations. Furthermore, explicit design requirements on the caps of bottles and composite beverage packaging have been introduced. These caps are typically made of polyethylene or polypropylene and often contain additives such as slip agents and anti-statics. Commercially available bottle cap recyclates (BCRs) as well as specifically formulated model compounds were analyzed in terms of composition by means of infrared spectroscopy, differential scanning calorimetry, and high-performance liquid chromatography. Their composition was found to be heterogeneous due to polyolefin cross-contamination, directly reflecting the diversity of cap materials present in the market. Slip agent legacy additives originating from the initial use phase were found and quantified in both commercial and model cap recyclates. This highlights the opportunity for redesigning plastic bottle caps not only in response to regulatory requirements, but to pursue a more comprehensive strategy of product design for circularity. By including considerations of polymer resin and additive choice in cap manufacturing, more homogeneous waste streams could be derived from plastic bottle cap recycling, enabling recycling into more demanding and valuable applications.

Purification and characterization of kraft lignin

Holzforschung ◽  
2015 ◽  
Vol 69 (8) ◽  
pp. 943-950 ◽  
Author(s):  
Wenwen Fang ◽  
Marina Alekhina ◽  
Olga Ershova ◽  
Sami Heikkinen ◽  
Herbert Sixta
Keyword(s):  
Thermal Properties ◽  
High Performance ◽  
Inorganic Compounds ◽  
Gel Permeation Chromatography ◽  
Kraft Lignin ◽  
Hot Water ◽  
Scanning Calorimetry ◽  
Target Values ◽  
Lower Glass Transition Temperature

Abstract To upgrade the utilization of kraft lignin (KL) for high-performance lignin-based materials (e.g., carbon fiber), the purity, molecular mass distribution (MMD), and thermal properties need to be improved and adjusted to target values. Therefore, different methods, such as ultrasonic extraction (UE), solvent extraction, dialysis, and hot water treatment (HWT), were applied for the purification of KL. The chemical and thermal properties of purified lignin have been characterized by nuclear magnetic resonance, Fourier transform infrared, gel permeation chromatography, elemental analysis, differential scanning calorimetry, and thermogravimetric analysis. The lignin fractions obtained by UE with ethanol/acetone (E/A) mixture (9:1) revealed a very narrow MMD and were nearly free of inorganic compounds and carbohydrates. Further, the E/A-extracted lignin showed a lower glass transition temperature (Tg) and a clearly detectable melting temperature (Tm). Dialysis followed by HWT at 220°C is an efficient method for the removal of inorganics and carbohydrates; however, lignin was partly forming condensed structures during the treatment.

On the Development and Characterization of Rheological and Mechanical Properties of Polylactide Blends with Polybutylene Adipate Terephthalate

2020 ◽  
Vol 850 ◽  
pp. 118-123
Author(s):  
Arturs Eriks Nesaule ◽  
Elina Didrihsone ◽  
Remo Merijs-Meri ◽  
Oskars Grigs ◽  
Jānis Zicāns
Keyword(s):  
Polymer Blend ◽  
High Performance ◽  
Impact Resistance ◽  
Structural Features ◽  
Scanning Calorimetry ◽  
Multi Stage ◽  
Research Cycle ◽  
Twin Screw ◽  
First Results

Within the current report the first results of the upcoming multi-stage research cycle on the development of high-performance environmentally friendly PLA/PBAT blend based composite materials are presented. Development and basic characterization of PLA/PBAT blends at various wt.-to-wt. ratios of the base polymeric components is performed. Rheological properties of PLA and PBAT have been investigated by means of rotational viscometry to define the optimal blending parameters. PLA/PBAT blends have been obtained by using twin-screw extrusion. Structural features of the obtained polymer blend compositions have been revealed by means of Fourier transform infrared spectroscopy. Crystallization behavior of the obtained polymer blend compositions have been characterized by means of differential scanning calorimetry. Thermal stability of the obtained polymer blend compositions has been studied by using thermogravimetric analysis. Mechanical behavior of the obtained polymer blend compositions has been studied by means of both quasistatic (in respects to tensile and flexural properties) and dynamic tests (impact resistance).

Development and characterization of homo, co and terpolyimides based on BPDA, BTDA, 6FDA and ODA with low dielectric constant

2014 ◽  
Vol 34 (9) ◽  
pp. 867-873 ◽  
Author(s):  
Revathi Purushothaman ◽  
I. Mohammed Bilal
Keyword(s):  
Dielectric Constant ◽  
High Performance ◽  
Low Dielectric Constant ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Low Dielectric ◽  
Imide Ring ◽  
Thermal Imidization ◽  
Tetracarboxylic Dianhydride

Abstract Polyimides are a sophisticated family of materials, which cover an exhaustive range of high performance polymers and find applications from aerospace to microelectronics. Microelectronic applications demand low dielectric constant and high performance. Aromatic terpolyimides were synthesized by reacting 3,3′,4,4′-biphenyl tetracarboxylic dianhydride (BPDA), 3,3′,4,4′-benzophenone tetracarboxylic dianhydride (BTDA) and 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) with 4,4′-oxydianiline (ODA) by thermal imidization with the view to decrease their dielectric constant without compromising thermal properties and mechanical properties compared to their homo and copolyimides. They were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Their FTIR spectra established formation of polyimide by the characteristic vibrations at 1375 cm-1 (C-N stretch) and 1113 cm-1 (imide ring deformation). The TGA results showed decomposition of imides at about 515°C. The glass transition temperature (Tg) of the polymers varied from 261°C to 281°C. The XRD spectrum of BPDA/BTDA/6FDA-ODA, which contained 50% of 6FDA, showed a broadened envelope with a peak at 16.8° (2θ), illustrating a semicrystalline nature. Incorporation of 6FDA, with a bulky bridging group into the backbone of BPDA/6FDA-ODA and BPDA/BTDA/6FDA-ODA (0.25:0.25:0.5::1) caused a decrease in the dielectric constant (2.13 and 2.38, respectively). Such polyimides can find application in microelectronics such as flexible printed circuits and tape automated bonding applications.

Characterization of Red Seaweed Extracts Treated by Water, Acid and Alkaline Solutions

2018 ◽  
Vol 14 (4) ◽  
Author(s):  
Ahmed Al-Alawi ◽  
Pothiraj Chitra ◽  
Abdullah Al-Mamun ◽  
Insaaf Al-Marhubi ◽  
Mohammad Shafiur Rahman
Keyword(s):  
High Performance ◽  
Thermal Characteristics ◽  
Bimodal Distribution ◽  
Ester Group ◽  
Alkaline Solutions ◽  
Molecular Characteristics ◽  
Red Seaweed ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry

Abstract Seaweed contained health functional polysaccharides and polyphenols. Five extracts were prepared from red seaweed Melanothamnus somalensis; two of these were aqueous at 20°C (F1) and 70°C (F2), followed by acid (F3), alkali (F4) and acid-washed (F5) treatments. Molecular characteristics of extracts were measured by high-performance liquid chromatography and Fourier transform infrared (FTIR) analyses. Health functionality was determined by sulfate and polyphenol contents, and thermal characteristics were determined by modulated differential scanning calorimetry. Extract F3 contained the highest levels of sulfate followed by F2, F1, F4 and F5, respectively. Similarly, F3 contained the highest polyphenol followed by F4, F2, F1 and F5, respectively. Molecular weight distribution of F1 showed wider distribution of sizes (MW: 1.0 × 103 – 3.0 × 107), and F5 showed a sharp peak (MW: 3.1 × 103); whereas F2, F3 and F4 indicated bimodal distribution. FTIR indicated that all fractions contained agar except F5 and sulfate ester group was attached to carbon 6 of the saccharide.

Light-cured dental composites characterization by Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 428-429
Author(s):  
B. M. Culbertson ◽  
M. L. Devinev ◽  
E. C. Kao
Keyword(s):  
Electron Microscopy ◽  
Mechanical Analysis ◽  
Service Performance ◽  
Dental Composite ◽  
Dental Composites ◽  
Neat Resin ◽  
Scanning Calorimetry ◽  
Research Meeting ◽  
Formulation Variables

The service performance of current dental composite materials, such as anterior and posterior restoratives and/or veneer cements, needs to be improved. As part of a comprehensive effort to find ways to improve such materials, we have launched a broad spectrum study of the physicochemical and mechanical properties of photopolymerizable or visible light cured (VLC) dental composites. The commercially available VLC materials being studied are shown in Table 1. A generic or neat resin VLC system is also being characterized by SEM and TEM, to more fully understand formulation variables and their effects on properties.At a recent dental research meeting, we reported on the differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) characterization of the materials in Table 1. It was shown by DSC and DMA that the materials are substantially undercured by commonly used VLC techniques. Post curing in an oral cavity or a dry environment at 37 to 50°C for 7 or more hours substantially enhances the cure of the materials.

Preparation and Characterization of NH2-Terminal Fibrinogen Bβ Fragments from N-DSK of Human Fibrinogen

1984 ◽  
Vol 51 (01) ◽  
pp. 016-021 ◽  
Author(s):  
S Birken ◽  
G Agosto ◽  
B Lahiri ◽  
R Canfield
Keyword(s):  
High Performance ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Reverse Phase ◽  
Human Fibrinogen ◽  
Human Volunteers ◽  
Cnbr Cleavage ◽  
Two Peaks

SummaryIn order to investigate the early release of NH2-terminal plasmic fragments from the Bβ chain of fibrinogen, substantial quantities of Bβ 1-42 and Bβ 1-21 are required as immunogens, as radioimmunoassay standards and for infusion into human volunteers to determine the half-lives of these peptides. Towards this end methods that employ selective proteolytic cleavage of these fragments from fibrinogen have been developed. Both the N-DSK fragment, produced by CNBr cleavage of fibrinogen, and Bβ 1-118 were employed as substrates for plasmin with the finding of higher yields from N-DSK. Bβ 1-42 and Bβ 1-21 were purified by gel filtration and ion-exchange chromatography on SP-Sephadex using volatile buffers. When the purified preparation of Bβ 1-42 was chromatographed on reverse-phase high performance liquid chromatography, two peaks of identical amino acid composition were separated, presumably due either to pyroglutamate or to amide differences.

Glibenclamide-Nicotinamide Cocrystals Synthesized by The Solvent Evaporation Method to Enhance Solubility and Dissolution Rate of Glibenclamide

2019 ◽  
Vol 9 (01) ◽  
pp. 21-26
Author(s):  
Arif Budiman ◽  
Ayu Apriliani ◽  
Tazyinul Qoriah ◽  
Sandra Megantara
Keyword(s):  
Solvent Evaporation ◽  
Physical Mixture ◽  
Dissolution Profile ◽  
Solvent Evaporation Method ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Evaporation Method ◽  
Dissolution Properties ◽  
Mixture Characterization

Purpose: To develop glibenclamide-nicotinamide cocrystals with the solvent evaporation method and evaluate their solubility and dissolution properties. Methods: Cocrystals of glibenclamide-nicotinamide (1:2) were prepared with the solvent evaporation method. The prediction of interactive cocrystals was observed using in silico method. The solubility and dissolution were performed as evaluation of cocrystals. The cocrystals also were characterized by differential scanning calorimetry (DSC), infrared spectrophotometry, and powder X-ray diffraction (PXRD). Result: The solubility and dissolution profile of glibenclamide-nicotinamide cocrystal (1:2) increased significantly compared to pure glibenclamide as well as its physical mixture. Characterization of cocrystal glibenclamide-nicotinamide (1:2) including infrared Fourier transform, DSC, and PXRD, indicated the formation of a new solid crystal phase differing from glibenclamide and nicotinamide. Conclusion: The confirmation of cocrystal glibenclamide-nicotinamide (1:2) indicated the formation of new solid crystalline phases that differ from pure glibenclamide and its physical mixture

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

Thermal Behaviour of Candesartan Active substance and in pharmaceutical compounds

2017 ◽  
Vol 68 (8) ◽  
pp. 1895-1902
Author(s):  
Ioana Cristina Tita ◽  
Eleonora Marian ◽  
Bogdan Tita ◽  
Claudia Crina Toma ◽  
Laura Vicas
Keyword(s):  
Thermal Behaviour ◽  
Active Substance ◽  
Pharmaceutical Research ◽  
Pharmaceutical Product ◽  
Nitrogen Atmosphere ◽  
Pure Substance ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir

Thermal analysis is one of the most frequently used instrumental techniques in the pharmaceutical research, for the thermal characterization of different materials from solids to semi-solids, which are of pharmaceutical relevance. In this paper, simultaneous thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) were used for characterization of the thermal behaviour of candesartan cilexetil � active substance (C-AS) under dynamic nitrogen atmosphere and nonisothermal conditions, in comparison with pharmaceutical product containing the corresponding active substance. It was observed that the commercial samples showed a different thermal profile than the standard sample, caused by the presence of excipients in the pharmaceutical product and to possible interaction of these with the active substance. The Fourier transformed infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRPD) were used as complementary techniques adequately implement and assist in interpretation of the thermal results. The main conclusion of this comparative study was that the TG/DTG and DSC curves, together with the FT-IR spectra, respectively X-ray difractograms constitute believe data for the discrimination between the pure substance and pharmaceutical forms.

Gelatin and Glycerine-Based Bioadhesive Vaginal Hydrogel

2020 ◽  
Vol 17 (4) ◽  
pp. 303-311
Author(s):  
Roberta Cassano ◽  
Federica Curcio ◽  
Delia Mandracchia ◽  
Adriana Trapani ◽  
Sonia Trombino
Keyword(s):  
Differential Scanning Calorimetry ◽  
Inflammatory Process ◽  
Vaginal Mucosa ◽  
Vaginal Infection ◽  
Scanning Calorimetry ◽  
Time Intervals ◽  
Site Specific ◽  
Release Studies ◽  
Hiv Seropositive

Aim: The work’s aim was the preparation and characterization of a hydrogel based on gelatin and glycerine, useful for site-specific release of benzydamine, an anti-inflammatory drug, able to attenuate the inflammatory process typical of the vaginal infection. Objective: The obtained hydrogel has been characterized by Electronic Scanning Microscopy (SEM) and Differential Scanning Calorimetry (DSC). In addition, due to the precursor properties, the hydrogel exhibits a relevant mucoadhesive activity. Methods: The swelling degree was evaluated at two different pHs and at defined time intervals. In particular, phosphate buffers were used at pH 6.6, in order to mimic the typical conditions of infectious diseases at the vaginal level, particularly for HIV-seropositive pregnant women, and pH 4.6, to simulate the physiological environment. Results: The obtained results revealed that the hydrogel swells up well at both pHs. Conclusion: Release studies conducted at both pathological and physiological pHs have shown that benzydamine is released at the level of the vaginal mucosa in a slow and gradual manner. These data support the hypothesis of the hydrogel use for the site-specific release of benzydamine in the vaginal mucosa.

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