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.

scholarly journals UV Polymerization of Methacrylates—Preparation and Properties of Novel Copolymers

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1659
Author(s):  
Marta Worzakowska
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Methyl Methacrylate ◽  
Chemical Resistance ◽  
Polymeric Materials ◽  
Monomer Content ◽  
Methacrylate Monomer ◽  
Methacrylate Monomers ◽  
Thermal Stability Of ◽  
Citronellyl Methacrylate

More environmentally friendly polymeric materials for use in corrosive conditions were obtained in the process of UV polymerization of terpene methacrylate monomers: geranyl methacrylate and citronellyl methacrylate and the commercially available monomer methyl methacrylate. Selected properties (solvent resistance, chemical resistance, glass transition temperature, thermal stability, and decomposition course during heating) were evaluated. It was found that the properties of the materials directly depended on the monomer percentage and the conditioning temperatures used. An increase in the geranyl or citronellyl methacrylate monomer content in the copolymers reduced the solubility and chemical resistance of the materials post-cured at 50 °C. The samples post-cured at 120 °C were characterized by high resistance to polar and non-polar solvents and the chemical environment, regardless of the percentage composition. The glass transition temperatures for samples conditioned at 120 °C increased with increasing content of methyl methacrylate in the copolymers. The thermal stability of copolymers depended on the conditioning temperatures used. It was greater than 200 °C for most copolymers post-cured at 120 °C. The process of pyrolysis of copolymers led to the emission of geranyl methacrylate, citronellyl methacrylate, and methyl methacrylate monomers as the main pyrolysis volatiles.

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 Powder Coating for Healthcare Aluminum Packaging

Cosmetics ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 20
Author(s):  
Stefano Rossi ◽  
Massimo Calovi ◽  
Matteo Tonelli
Keyword(s):  
Dimethyl Ether ◽  
Chemical Resistance ◽  
Powder Coating ◽  
Visual Observation ◽  
Pharmaceutical Product ◽  
Powder Coatings ◽  
Product Packaging ◽  
Alcohol Water ◽  
Protective System ◽  
Aluminum Cans

Restrictive regulations concerning the toxicity of certain compounds and the use and disposal of solvents present in the liquid epoxy protection system have been analyzed in this work to evaluate powder coatings as an alternative in the protection of aerosol aluminum cans, which are employed in cosmetics and pharmaceutical product packaging. In this paper, the chemical resistance of polyester and mixed epoxy-polyester powder coatings is assessed, considering different aggressive environments employed in healthcare commercial products. The samples’ performances are also compared with the currently used liquid organic coatings. The pack test has been used to evaluate the protective system behavior in contact with both the liquid and the gaseous part of the cosmetic product. However, the visual observation, required by the test, enabled the highlight of only very evident degradation phenomena. The chemical resistance of the powder coatings has proved to be appropriate only for less aggressive environment, where the critical compounds are propellants, propane, butane and isobutane. When exposed to other environments containing alcohol, water and dimethyl ether, most samples have been susceptible to layer degradation phenomena. Polyester layers lose their corrosion protection properties. Epoxy systems, instead, result more performant than polyester resins, but they particularly suffer from the contact with dimethyl ether.

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 Investigation of the functional network modifier loading on the stoichiometric ratio of epoxy resins and their dielectric properties

2021 ◽  
Author(s):  
Istebreq A. Saeedi ◽  
Sunny Chaudhary ◽  
Thomas Andritsch ◽  
Alun S. Vaughan
Keyword(s):  
Glass Transition ◽  
Dielectric Properties ◽  
Electrical Properties ◽  
Epoxy Resins ◽  
Functional Network ◽  
Cross Linking ◽  
Network Modifier ◽  
Epoxy Resin System ◽  
The Cross ◽  
The Impact

AbstractReactive molecular additives have often been employed to tailor the mechanical properties of epoxy resins. In addition, several studies have reported improved electrical properties in such systems, where the network architecture and included function groups have been modified through the use of so-called functional network modifier (FNM) molecules. The study reported here set out to investigate the effect of a glycidyl polyhedral oligomeric silsesquioxane (GPOSS) FNM on the cross-linking reactions, glass transition, breakdown strength and dielectric properties of an amine-cured epoxy resin system. Since many previous studies have considered POSS to act as an inorganic filler, a key aim was to consider the impact of GPOSS addition on the stoichiometry of curing. Fourier transform infrared spectroscopy revealed significant changes in the cross-linking reactions that occur if appropriate stoichiometric compensation is not made for the additional epoxide groups present on the GPOSS. These changes, in concert with the direct effect of the GPOSS itself, influence the glass transition temperature, dielectric breakdown behaviour and dielectric response of the system. Specifically, the work shows that the inclusion of GPOSS can result in beneficial changes in electrical properties, but that these gains are easily lost if consequential changes in the matrix polymer are not appropriately counteracted. Nevertheless, if the system is appropriately optimized, materials with pronounced improvements in technologically important characteristics can be designed.

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.

Investigating the role of GeO2 in enhancing the thermal stability and proton mobility of proton-conducting phosphate glasses

2021 ◽  
Author(s):  
Takahisa Omata ◽  
Aman Sharma ◽  
Takuya Kinoshita ◽  
Issei Suzuki ◽  
Tomohiro Ishiyama ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Phosphate Glasses ◽  
Proton Mobility ◽  
Proton Conducting

In this study, the effect of GeO2 on the thermal stability and proton mobility (μH) of proton-conducting phosphate glasses was experimentally investigated using 22HO1/2−3NaO1/2−(12−x)LaO3/2−xGeO2−63PO5/2 glasses. Increasing glass transition temperature (Tg)...

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.

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