scholarly journals Protective paints from natural resources: composition and properties

Polimery ◽  
2021 ◽  
Vol 66 (7-8) ◽  
Author(s):  
Szymon Kugler ◽  
Paula Ossowicz-Rupniewska ◽  
Ewa Wierzbicka ◽  
Jakub Łopiński
Keyword(s):  
Thermal Stability ◽  
Natural Resources ◽  
Renewable Resources ◽  
Climate Changes ◽  
Chemical Resistance ◽  
Protective Coatings ◽  
Reference Sample ◽  
The Other ◽  
Cross Linking ◽  
Glass Transition Temperatures

Climate changes and increasing cost of non-renewable resources cause the growing interest in technical materials prepared from natural resources. To meet this interest, prototype paints from rosin and bio-diols derivatives, and also halloysite, were formulated to check their thermal, mechanical, visual and functional properties, as protective coatings of steel. Prepared materials contained ca. 75 wt.% of natural resources and exhibited considerably better corrosion protection, thermal stability, and also higher glass transition temperatures and hardness, than a commercial petroleum-based reference sample. The other parameters: cross-linking behavior, color, gloss, cupping resistance, adhesion and chemical resistance were within the range that is acceptable for potential users.

scholarly journals Composition and Properties of Protective Coatings Made of Biologically-Derived Polyester Reactive Binder

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1700
Author(s):  
Szymon Kugler ◽  
Ewa Wierzbicka ◽  
Paula Ossowicz-Rupniewska ◽  
Jakub Łopiński
Keyword(s):  
Chemical Resistance ◽  
Raw Materials ◽  
Protective Coatings ◽  
Developed Countries ◽  
Cross Linking ◽  
Coating Materials ◽  
Ecological Requirements ◽  
Volatile Organic ◽  
Zero Carbon ◽  
Steel Substrates

Biologically derived polymers are a very attractive subject for investigation, due to the strict pro-ecological requirements imposed by developed countries, including zero-waste and zero-carbon policies as well as volatile organic compound (VOC) limits. Synthesis of biologically-derived polyesters from natural rosin and bio-diols, showing softening temperatures suitable for application in VOC-free paints and varnishes, was performed to create a desired, future commercial product, that meet the aforementioned requirements regarding VOC and elimination of petroleum-based raw materials. Prepared polymers were used in the formulation of coating materials whose properties: cross-linking behavior, glass transition temperature, thermal stability, storage modulus, hardness, cupping resistance, adhesion, chemical resistance, gloss, haze, color, and anti-corrosive behavior in the salt chamber were investigated and discussed. As a result, coatings with prepared bio-polyesters contained over 80 wt.% of natural resources and showed competitive/better properties than petroleum-based references. They can be applied in the prototyping of “green” powder paints for the protection of steel substrates from corrosion and aggressive solvents.

Introducing an Innovative Perfluoroelastomer Cross Linking Technology: Achieving Superior Chemical Resistance and Thermal Stability

2021 ◽  
Author(s):  
Jimmy Alvarez ◽  
Christopher J. Bish ◽  
Andres Rodriguez
Keyword(s):  
Thermal Stability ◽  
Chemical Resistance ◽  
Standardized Test ◽  
Test Methods ◽  
Cross Linking ◽  
Cross Link ◽  
Cross Links ◽  
The Cross ◽  
Almost All ◽  
Performance Results

Objectives/Scope Perfluoroelastomers are a class of synthetic elastomers that provide extraordinary resistance to oils, chemicals, and heat. The outstanding thermal stability and excellent corrosion resistance of these materials is dependent on the perfluorinated polymer chain, and the absence of unsaturation. However, the cross-link which is necessary to impart elastomeric properties must also share those stability traits. Unfortunately, designing a suitably inert cross-link is technically difficult to achieve and consequently it has not been possible to provide the ultimate in perfluoroelastomer properties. This paper is a review of the cross-linking chemistry of perfluoroelastomers and highlight a novel and patented cross-link which combines broad chemical resistance and superior thermal stability. Methods, Procedures, Process Several perfluoroelastomers formulations were selected and tested using representative standardized test methods to quantify their performance. The testing included compression set resistance, swell in fluids, and compression stress relaxation. In addition to the testing, chemistry of the cross-link was explained and how it is related to the observed performance results. The novel cross-link, triazole, was identified as an improvement versus existing cross-links. Results, Observations, Conclusions The testing demonstrated that previously available perfluoroelastomer cross-link chemistries display compromises in overall performance. For example, it had not been possible to achieve high thermal stability combined with resistance to almost all fluids. Overall, the data generated showed that the newly developed triazole cross-link system broadens the performance envelope of perfluoroelastomers and helps to alleviate the compromises of the past. Novel/Additive Information The newly discovered triazole cross-link with enhanced chemical and thermal stability enables broader use of perfluoroelastomers in extreme applications.

scholarly journals Anhydride-Cured Epoxy Powder Coatings from Natural-Origin Resins, Hardeners, and Fillers

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 531
Author(s):  
Szymon Kugler ◽  
Paula Ossowicz-Rupniewska ◽  
Ewa Wierzbicka ◽  
Jakub Łopiński
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Chemical Resistance ◽  
Powder Coating ◽  
Market Force ◽  
Cross Linking ◽  
Powder Coatings ◽  
Natural Origin ◽  
Market Needs ◽  
Steel Substrates

Carbon-neutral policy and technological race on the powder coatings market force to develop more advanced, safer, cheaper, and naturally sourced products. To meet the market needs, powder coating compositions and coatings were prepared from safe and natural-origin hardeners, resins, and fillers prepared from rosin, bio-diols, bio-epichlorohydrin, and halloysite, to investigate their thermal, mechanical, and functional properties in comparison with petroleum-based references: cross-linking behavior, glass transition temperature, thermal stability, hardness, cupping resistance, adhesion, chemical resistance, gloss, color, and anti-corrosive behavior in salt chamber. As a result, compositions containing up to 83 wt.% of natural resources, and showing comparable or better properties, as compared to references, were successfully prepared. Their application includes binders for future ecological powder paints for demanding protection of steel substrates.

The Effect of the Vulcanizing System on Cure and Mechanical Properties of Nbr/Epdm Blends

2001 ◽  
Vol 9 (7) ◽  
pp. 459-468 ◽  
Author(s):  
Marcia G. Oliveira ◽  
Bluma G. Soares
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Glass Transition ◽  
Crosslink Density ◽  
Mechanical Performance ◽  
The Other ◽  
Glass Transition Temperatures ◽  
Sulphur Concentration ◽  
Curing Characteristics ◽  
Accelerator System

The effect of the curing system and curing parameters, mechanical properties, ageing resistance, and crosslink density of NBR/EPDM blends has been investigated. The curing characteristics of the blends were affected by the accelerator type and the sulphur concentration. The sulphur/benzothiazyl-disulphide (S/MBTS) vulcanizing system offered the best scorch safety, whereas those single and binary accelerator systems based on tetramethyl thiuram disulphide (TMTD) provided faster cure. The MBTS single accelerator system was able to crosslink the EPDM phase better and consequently displayed better mechanical performance than the other systems based on tetramethyl thiuram disulphide (TMTD). Higher thermal stability was also achieved in blends containing higher levels of sulphur, probably because of increased crosslinking in the EPDM phase. The results of dynamic mechanical investigations showed differences in the glass transition temperatures, which increased with increasing of the sulphur content in both S/MBTS and S/MBTS/TMTD vulcanizing systems. Formulations based on S/TMTD single accelerator systems gave the lowest values of Tg, and the amount of sulphur did not affect this property.

The Challenges of Implementing E-Commerce in Kurdistan of Iraq

2016 ◽  
Vol 2 (3) ◽  
pp. 528
Author(s):  
Ako Abubakr Jaffar ◽  
Mazen Ismaeel Ghareb ◽  
Karzan Hussein Sharif
Keyword(s):  
Middle East ◽  
Natural Resources ◽  
Online Shopping ◽  
Deep Understanding ◽  
The Other ◽  
Regional Government ◽  
Security Measures ◽  
Unique Region ◽  
Government Organizations ◽  
The World

The Retailers all over the world are prospering from the burgeoning trend of online shopping. Kurdistan Regional Government is still struggling to grow its e-commerce markets. On the other hands e-commerce in Various countries in the Middle East have some of the world’s highest internet and mobile penetration rates. Alternative payments methods are quickly expanding, and having access to some of the world’s most coveted natural resources that allows countries in their region to have some of the highest GDP in the world. There are several challenges prevalent in the KRG Region market that will require international merchants to develop strategies based on innovation and vigilance. This unique region is plagued with complications many other countries have little to no experience with e-commerce, which highlights the need for retailers to have a deep understanding as to how this region operates before they can begin finding solutions. One of the biggest concerns today's consumers have is the risk of fraud when they are shopping online. With highly sophisticated malware and perceptive cybercriminals, customers' card and bank information can easily be stolen if a merchant does not take the proper security measures. In this paper we summarize all challenges need to be addressed in KRG in order to make correct steps to apply e-commerce in KRG. Finally, the recommendations and framework are proposed for e-commerce to encourage government, organizations, and people to take advantages from e-commerce.

scholarly journals A comprehensive analysis of novel disulfide bond introduction site into the constant domain of human Fab

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hitomi Nakamura ◽  
Moeka Yoshikawa ◽  
Naoko Oda-Ueda ◽  
Tadashi Ueda ◽  
Takatoshi Ohkuri
Keyword(s):  
Thermal Stability ◽  
Pichia Pastoris ◽  
Protein Stability ◽  
Disulfide Bond ◽  
Binding Activity ◽  
Comprehensive Analysis ◽  
The Other ◽  
Constant Domain ◽  
Intermolecular Disulfide Bond ◽  
Sds Page

AbstractGenerally, intermolecular disulfide bond contribute to the conformational protein stability. To identify sites where intermolecular disulfide bond can be introduced into the Fab’s constant domain of the therapeutic IgG, Fab mutants were predicted using the MOE software, a molecular simulator, and expressed in Pichia pastoris. SDS-PAGE analysis of the prepared Fab mutants from P. pastoris indicated that among the nine analyzed Fab mutants, the F130C(H):Q124C(L), F174C(H):S176C(L), V177C(H):Q160C(L), F174C(H):S162C(L), F130C(H):S121C(L), and A145C(H):F116C(L) mutants mostly formed intermolecular disulfide bond. All these mutants showed increased thermal stability compared to that of Fab without intermolecular disulfide bond. In the other mutants, the intermolecular disulfide bond could not be completely formed, and the L132C(H):F118C(L) mutant showed only a slight decrease in binding activity and β-helix content, owing to the exertion of adverse intermolecular disulfide bond effects. Thus, our comprehensive analysis reveals that the introduction of intermolecular disulfide bond in the Fab’s constant domain is possible at various locations. These findings provide important insights for accomplishing human Fab stabilization.

scholarly journals Enzymatic and Chemical Cross-Linking of Bacterial Cellulose/Fish Collagen Composites—A Comparative Study

2021 ◽  
Vol 22 (7) ◽  
pp. 3346
Author(s):  
Agata Sommer ◽  
Paulina Dederko-Kantowicz ◽  
Hanna Staroszczyk ◽  
Sławomir Sommer ◽  
Marek Michalec
Keyword(s):  
Thermal Stability ◽  
Bacterial Cellulose ◽  
Secondary Alcohol ◽  
Water Vapor Permeability ◽  
Polymer Chains ◽  
Cross Linking ◽  
Vapor Permeability ◽  
Covalent Bonds ◽  
Fish Collagen ◽  
Chemical Cross Linking

This article compares the properties of bacterial cellulose/fish collagen composites (BC/Col) after enzymatic and chemical cross-linking. In our methodology, two transglutaminases are used for enzymatic cross-linking—one recommended for the meat and the other proposed for the fish industry—and pre-oxidated BC (oxBC) is used for chemical cross-linking. The structure of the obtained composites is characterized by scanning electron microscopy, thermogravimetric analysis, X-ray diffraction, and Fourier transform infrared spectroscopy, and their functional properties by mechanical and water barrier tests. While polymer chains in uncross-linked BC/Col are intertwined by H-bonds, new covalent bonds in enzymatically cross-linked ones are formed—resulting in increased thermal stability and crystallinity of the material. The C2–C3 bonds cleavage in D-glucose units, due to BC oxidation, cause secondary alcohol groups to vanish in favor of the carbonyl groups’ formation, thus reducing the number of H-bonded OHs. Thermal stability and crystallinity of oxBC/Col remain lower than those of BC/Col. The BC/Col formation did not affect tensile strength and water vapor permeability of BC, but enzymatic cross-linking with TGGS improved them significantly.

scholarly journals Biopolymers from Natural Resources

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2532
Author(s):  
Rafael Balart ◽  
Daniel Garcia-Garcia ◽  
Vicent Fombuena ◽  
Luis Quiles-Carrillo ◽  
Marina P. Arrieta
Keyword(s):  
Environmental Impact ◽  
Natural Resources ◽  
Renewable Resources

During the last decades, the increasing ecology in the reduction of environmental impact caused by traditional plastics is contributing to the growth of more sustainable plastics with the aim to reduce the consumption of non-renewable resources for their production [...]

The effect of methyl and methoxy substituents on dianilines for a thermosetting polyimide system

2020 ◽  
Vol 32 (7) ◽  
pp. 801-822 ◽  
Author(s):  
John J La Scala ◽  
Greg Yandek ◽  
Jason Lamb ◽  
Craig M Paquette ◽  
William S Eck ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Glass Transition ◽  
Elevated Temperature ◽  
Methyl Substituent ◽  
Glass Transition Temperatures ◽  
High Performing ◽  
Methoxy Substituent ◽  
Acidic Conditions ◽  
Thermal Stability Of

4,4′-Methylenedianiline (MDA) is widely used in high-temperature polyimide resins, including polymerization of monomer reactants-15. The toxicity of MDA significantly limits the manufacturability using this resin. Modifying the substitution and electronics of MDA could allow for the reduction of toxicity while maintaining the high-performing properties of the materials derived from the modified MDA. The addition of a single methyl substituent, methoxy substituent, location of these substituents, and location of the amine relative to the phenolic bridge were modified as were other non-aniline diamines. Various anilines were condensed with paraformaldehyde under acidic conditions to yield dianilines. These dianilines and diamines were reacted with nadic anhydride and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride in methanol to form the polyamic acid oligomers and heated at elevated temperature to form polyimide oligomers. It was found that the molecular weight of the oligomers derived from MDA alternatives was generally lower than that of MDA oligomers resulting in lower glass transition temperatures ( T gs) and degradation temperatures. Additionally, methoxy substituents further reduce the T g of the polymers versus methyl substituents and reduce the thermal stability of the resin. Methyl-substituted alternatives produced polyimides with similar T gs and degradation temperatures. The toxicity of the MDA alternatives was examined. Although a few were identified with reduced toxicities, the alternatives with properties similar to that of MDA also had high toxicities.

Sign in / Sign up

Export Citation Format

Share Document