Natural compounds as light stabilizer for a starch-based biodegradable polymer

2014 ◽  
Vol 34 (5) ◽  
pp. 441-449 ◽  
Author(s):  
NadkaTz. Dintcheva ◽  
Francesco Paolo La Mantia ◽  
Rossella Arrigo
Keyword(s):  
Biodegradable Polymer ◽  
Natural Compounds ◽  
Mechanical Tests ◽  
Flavonoid Compound ◽  
Biodegradable Films ◽  
Biodegradable Film ◽  
Light Stabilizer ◽  
Agricultural Applications ◽  
New Generation ◽  
Better Than

Abstract The photooxidation behavior of a commercial starch-based biodegradable polymer, i.e., new generation Mater-Bi, loaded with natural stabilizers was investigated in consideration for outdoor agricultural applications. The photooxidation behavior of the biodegradable films was monitored mainly by mechanical tests and spectroscopic analysis. In order to formulate biodegradable films without any synthetic compounds, suitable for outdoor applications and with good photooxidation stability, antioxidants such as α-tocopherol and quercetin (Q) were considered. The results obtained using natural compounds were compared with those obtained by using a synthetic antioxidant and a light stabilizer. Among the investigated natural compounds, the flavonoid compound seemed to work better than the antioxidant and the improvement in the photooxidation behavior of the biodegradable film was very similar to that obtained using the synthetic light stabilizer. A flavonoid compound can be considered as an outstanding natural stabilizer to replace synthetic light stabilizers in the formulation of 100% natural compounds based films, suitable for outdoor applications.

Finding the Right Problems: Some HREM Applications to Interfaces

1984 ◽  
Vol 42 ◽  
pp. 376-379
Author(s):  
D. Cherns
Keyword(s):  
Grain Boundaries ◽  
High Resolution Electron Microscopy ◽  
Boundary Structure ◽  
Atomic Structures ◽  
Grain Boundary Structure ◽  
Resolution Electron ◽  
Point To Point ◽  
The Right ◽  
New Generation ◽  
Better Than

The use of high resolution electron microscopy (HREM) to determine the atomic structure of grain boundaries and interfaces is a topic of great current interest. Grain boundary structure has been considered for many years as central to an understanding of the mechanical and transport properties of materials. Some more recent attention has focussed on the atomic structures of metalsemiconductor interfaces which are believed to control electrical properties of contacts. The atomic structures of interfaces in semiconductor or metal multilayers is an area of growing interest for understanding the unusual electrical or mechanical properties which these new materials possess. However, although the point-to-point resolutions of currently available HREMs, ∼2-3Å, appear sufficient to solve many of these problems, few atomic models of grain boundaries and interfaces have been derived. Moreover, with a new generation of 300-400kV instruments promising resolutions in the 1.6-2.0 Å range, and resolutions better than 1.5Å expected from specialist instruments, it is an appropriate time to consider the usefulness of HREM for interface studies.

Masers as probes of the gas dynamics close to forming high-mass stars

2017 ◽  
Vol 13 (S336) ◽  
pp. 201-206 ◽  
Author(s):  
Luca Moscadelli ◽  
Alberto Sanna ◽  
Ciriaco Goddi
Keyword(s):  
Gas Dynamics ◽  
Very Long Baseline Interferometry ◽  
High Mass ◽  
Powerful Technique ◽  
Long Baseline ◽  
Vlbi Observations ◽  
Massive Forming ◽  
Typical Distances ◽  
New Generation ◽  
Better Than

AbstractImaging the inner few 1000 AU around massive forming stars, at typical distances of several kpc, requires angular resolutions of better than 0″.1. Very Long Baseline Interferometry (VLBI) observations of interstellar molecular masers probe scales as small as a few AU, whereas (new-generation) centimeter and millimeter interferometers allow us to map scales of the order of a few 100 AU. Combining these informations all together, it presently provides the most powerful technique to trace the complex gas motions in the proto-stellar environment. In this work, we review a few compelling examples of this technique and summarize our findings.

A Design of High-Accuracy Displacement Measurement Instrument from Principles of Optics

2012 ◽  
Vol 170-173 ◽  
pp. 2924-2928
Author(s):  
Sheng Biao Chen ◽  
Yun Zhi Tan
Keyword(s):  
Measurement Instrument ◽  
High Accuracy ◽  
Mechanical Tests ◽  
Total Reflection ◽  
Displacement Measurement ◽  
New Method ◽  
Water Volume ◽  
Water Drainage ◽  
Accuracy Of Measurement ◽  
Better Than

In order to measure the water drainage volume in soil mechanical tests accurately, it develop a new method which is based on principles of optics. And from both physical and mathematic aspects, it deduces the mathematic relationship between micro change in displacement and the increment projected on screen. The result shows that total reflection condition is better than refraction condition. What’s more, the screen could show the water volume micro variation clearly, so it can improve the accuracy of measurement.

scholarly journals Synthesis of biodegradable films obtained from rice husk and sugarcane bagasse to be used as food packaging material

2019 ◽  
Vol 25 (4) ◽  
pp. 506-514 ◽  
Author(s):  
Himanshu Gupta ◽  
Harish Kumar ◽  
Mohit Kumar ◽  
Avneesh Kumar Gehlaut ◽  
Ankur Gaur ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Sugarcane Bagasse ◽  
Rice Husk ◽  
Food Packaging ◽  
Packaging Material ◽  
Biodegradable Films ◽  
Biodegradable Film ◽  
Biocomposite Film ◽  
Biopolymer Film ◽  
Lignocellulose Biomass

The current study stresses on the reuse of waste lignocellulose biomass (rice husk and sugarcane bagasse) for the synthesis of carboxymethyl cellulose (CMC) and further conversion of this CMC into a biodegradable film. Addition of commercial starch was done to form biodegradable film due to its capacity to form a continuous matrix. Plasticizers such as Glycerol and citric acid were used to provide flexibility and strength to the film. Biopolymer film obtained from sugarcane bagasse CMC showed maximum tensile strength and elongation in comparison to the film synthesized from commercial CMC and CMC obtained from rice husk. It has been observed that an increase in sodium glycolate/NaCl content in CMC imposed an adverse effect on tensile strength. Opacity, moisture content, and solubility of the film increased with a rise in the degree of substitution of CMC. Therefore, CMC obtained from sugarcane bagasse was better candidate in preparing biopolymer/biocomposite film.

scholarly journals Preparation and Characterization of New Environmentally Friendly Starch-Cellulose Materials Modified with Casein or Gelatin for Agricultural Applications

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1684 ◽  
Author(s):  
Mirosława Prochoń ◽  
Anna Marzec ◽  
Bolesław Szadkowski
Keyword(s):  
Chemical Properties ◽  
Mechanical Tests ◽  
Infrared Analysis ◽  
Scanning Calorimetry ◽  
Absorption Bands ◽  
Cellulose Composites ◽  
Vis Spectroscopy ◽  
Agricultural Applications ◽  
Starch Films ◽  
Cellulose Fabrics

The purpose of this work was to prepare new biodegradable starch-cellulose composites, with starch, using casein and gelatin as natural nutrients. The physico-chemical properties of the starch films and cellulose fabrics with starch coatings were studied by Fourier transformation infrared analysis, laser confocal scanning microscopy (LCSM), scanning electron microscopy (SEM), UV-Vis spectroscopy, swelling tests, mechanical tests, thermal analysis thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The susceptibility of the starch films to biodegradation was investigated, together with their resistance to thermo-oxidative aging. As a result of the formation of the starch films, both the casein and gelatin macromolecules were able to interact directly with the starch matrix and the fractions of unbranched amylose and branched amylopectin it contained. This interaction was visible as changes in the absorption bands of the polar groups, as revealed by infrared analysis. Spectral analysis of the cellulose fabrics coated with starch films suggests that hydrogen bridges formed between the micelles of long cellulose filaments and the micro and macro-fibers of the starch pectins. An applicative test revealed that when used as a covering for bean cultivation the cellulose-starch composites act as a fertilizing component, contributing to significantly improved growth of Phaseolus vulgaris in comparison to the use of unmodified cellulose.

P3385Difference of vascular healing after percutaneous coronary intervention between 4 kinds of new generation drug-eluting stents: an optical coherence tomography analysis

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
Y Matsuhiro ◽  
M Nishino ◽  
H Nakamura ◽  
K Yasumoto ◽  
A Tanaka ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Biodegradable Polymer ◽  
Neointimal Hyperplasia ◽  
Drug Eluting Stents ◽  
P Value ◽  
Optical Coherence ◽  
Durable Polymer ◽  
Drug Eluting ◽  
New Generation

Abstract Background New generation drug eluting stents (DES) have improved target vessel failure as compared with early generation DES and bare metal stent. Contemporary several new generation DES are different each other regarding strut thickness and drug and polymer type. A little is known about which stent induces a more favorable vascular healing at follow up. Purpose In this study, we compared the vascular healing at 8-month follow up by optical coherence tomography (OCT) between 4 different kinds of new generation DES. Methods We enrolled 112 consecutive patients (121 lesions) who underwent PCI using 4 kinds of new generation DES including biodegradable-polymer everolimus-eluting stents (BP-EES), biodegradable-polymer sirolimus-eluting stents (BP-SES), durable-polymer everolimus-eluting stents (DP-EES) and durable-polymer zotarolimus-eluting stents (DP-ZES) and who underwent 8-month follow up angiogram and OCT between July 2016 and April 2018. We compared the OCT parameters including percentage of covered struts, uncovered struts, well-apposed and uncovered struts, malapposed strut and mean neointimal hyperplasia (NIH) thickness between them. Results BP-EES consisted of 29 lesions, BP-SES consisted of 25 lesions, DP-EES consisted of 38 lesions and DP-ZES consisted of 29 lesions. A total of 734 frames with 5163 struts in BP-EES, 481 frames with 4214 struts in BP-SES, 783 frames with 6119 struts in DP-EES and 583 frames with 4708 struts in DP-ZES were analyzed. As shown in a table, mean NIH thickness was significantly higher in BP-EES and BP-SES. Thus, we compared the OCT parameters between durable-polymer (DP) group including DP-ZES and DP-EES and biodegradable-polymer (BP) group including BP-EES and BP-SES. The percentage of uncovered struts was significantly lower and mean NIH thickness was significantly higher in BP group than DP group. Results of OCT parameters BP-EES (n=29) BP-SES (n=25) DP-EES (n=38) DP-ZES (n=29) P value BP group (n=54) DP group (n=67) P value Covered struts (%) 89.5±13.6 92.4±8.6 85.5±17.5 85.0±17.7 0.29 90.9±11.6 85.3±17.4 0.08 Uncovered struts (%) 8.8±10.8 7.1±8.7 14.5±17.5 15.0±17.7 0.14 8.0±9.9 14.7±17.4 0.03 Well-apposed and uncovered struts (%) 7.9±9.9 5.9±7.7 11.7±13.1 12.3±14.0 0.15 7.0±8.9 11.9±13.4 0.04 Malapposed struts (%) 0.8±1.6 1.3±2.2 2.7±5.8 2.7±4.7 0.33 1.0±1.9 2.7±5.3 0.07 Mean NIH thickness (μm) 102±57 121±48 78±28 88±33 <0.01 111±53 82±31 <0.01 Conclusion The present OCT study demonstrated that delayed neointimal healing characterized by the presence of uncovered struts and lower mean NIH thickness was less common in BP group than DP gruop. Biodegradable-polymer may be more favorable than durable-polymer from the point of view of vascular healing.

BIODEGRADABLE FILM FROM Pleurotus sajor-caju WASTE

2016 ◽  
Vol 78 (11-2) ◽  
Author(s):  
Hazwani Husain ◽  
Ahmad Yazid Rahman ◽  
Norshazila Senawi ◽  
Yamunasri A/P Kuthiah ◽  
Syaliyana Khairudin ◽  
...  
Keyword(s):  
Environmental Concern ◽  
Testing Machine ◽  
Biodegradable Films ◽  
Biodegradable Film ◽  
Universal Testing Machine ◽  
Universal Testing ◽  
The World ◽  
Pleurotus Sajor Caju

The accumulation of waste is a growing environmental concern on the issues all around the world.  One green option is to convert waste into valuable materials.  This study aims to recycle mushroom waste from Pleurotus sajor-caju from ‘Rumah Cendawan’, Politeknik Nilai to develop biofilm which has the potential to be molded into a variety of products.  Forty two formulations have been molded and 14 best formulations have been tested.  The tensile strengths of these 14 biofilms have been determined by using Shimadzu Universal Testing Machine and the biodegradability characteristics of the films have been tested.  In a conclusion, biodegradable films from Pleurotus sajor-caju waste can be developed as a better alternative to the existing plastics in the market.

scholarly journals Natural Compounds for Wood Protection against Fungi—A Review

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3538
Author(s):  
Magdalena Broda
Keyword(s):  
Field Performance ◽  
Natural Compounds ◽  
Wood Products ◽  
Animal Origin ◽  
Successful Implementation ◽  
Wood Protection ◽  
And Performance ◽  
Potential Methods ◽  
Natural Preservatives ◽  
New Generation

Wood is a renewable, versatile material with multiple applications and the largest terrestrial pool of sequestered carbon. However, it is susceptible to degradation, mainly caused by wood-decaying fungi. Since several traditional wood preservatives have been banned owing to their detrimental effects on humans and the environment, extending the lifespan of wood products using new generation natural preservatives is an imperative from the perspectives of human health and environmental protection. Several natural compounds of plant and animal origin have been tested for their fungicidal properties, including essential oils, tannins, wood extractives, alkaloids, propolis or chitosan; and their enormous potential in wood protection has been shown. Although they are not free of limitations, the potential methods to overcome their drawbacks and enhance their bioactivity already exist, such as co-impregnation with different polymers, cross-linkers, metal chelators or antioxidants. The presence of the discrepancies between laboratory tests and the field performance, as well as legislation-related problems resulting from the lack of standards defining the quality and performance of natural protective formulations, however, create an urgent need for further thorough research and arrangements. The collaboration with other industries interested in the utilisation of natural active compounds will reduce the associated costs, thus, will facilitate the successful implementation of alternative antifungal agents.

Determination of Fracture Mechanical Properties of Carbon Bonded Alumina Using Miniaturized Specimens

2016 ◽  
Vol 713 ◽  
pp. 70-73 ◽  
Author(s):  
H. Zielke ◽  
Martin Abendroth ◽  
Meinhard Kuna
Keyword(s):  
Mechanical Properties ◽  
Filter Material ◽  
Mechanical Tests ◽  
Ceramic Foam ◽  
Ceramic Filter ◽  
Tensile Fracture ◽  
Displacement Curve ◽  
Punch Test ◽  
New Generation ◽  
Filter Structures

Open cell ceramic foam filters are utilized to reduce non-metallic inclusions during casting of metals and therefore to enhance the quality of cast parts. A new generation of multifunctional filters made of carbon bonded alumina (Al2O3-C) has been developed within the scope of the collaborative research center CRC 920 [1]. The assessment of the resistance against high thermal and mechanical loads requires a mechanical characterization of the ceramic filter material. The mechanical properties show a distinctive size dependency, that’s why the specimen dimensions should be similar to the strut size of the real filter structures. The tensile fracture behavior is investigated by means of the Small Punch Test (SPT) using miniaturized disk-shaped specimens. During the mechanical tests a load-displacement curve is measured until failure occurs and a fracture stress is calculated from the experimental results. An estimation about the failure probability by means of Weibull statistics is performed because of the large scatter of the strength of the material. Furthermore, a modified version of the SPT, the so called Ball On Three Balls Test (B3B), is applied and compared to the SPT. In a final step numerical simulations of the B3B tests are performed by means of the finite element method to identify fracture mechanical material parameters like the fracture toughness.

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