“Chemical Dynamic’s formulating experience and the ability to innovate provided invaluable assistance to optimize performance of paint systems using our superhydrophobic material for aerospace and other applications. I can recommend there company to anyone seeking expertise and support in paint and coatings”
Nanoparticles (EU) are normally defined as those particles that have a dimension of between 1 and 100 nm. The use of nanoparticles in coatings has provided a means to further improve performance such as scratch resistance, hardness, antistatic properties and UV resistance. These performance attributes are derived from the property profiles of nanoparticles.
Nanoparticles provide the inherent properties of the material they are derived from. For example, nano alumina (EU)maintains the properties of alumina, such as hardness and scratch resistance, but only on a nanoscale. Likewise, nano silica(EU) provides hardness, nano titanium dioxide provides a high refractive index and UV stabilization, and nano zinc oxide(EU) remains a UV light absorber (EU), even if the zinc oxide particles are nano-sized. The benefits of these materials are imparted to the coatings that they are used in.
The most pronounced property that is influenced by the particle size is the change in light scattering. For example, nano-sized particles may produce transparent coatings as light-scattering decreases with decreasing particle size. Most objects are visible due to light scattering from their surfaces. Scattering of light depends on the wavelength or frequency of the light being scattered as well as the size, shape and type of particle.
Since visible light has a wavelength on the order of micrometers, most particles much smaller than this, such as nano particles, are mostly transparent as their ability to scatter light diminishes with their size. However, light scattering is also dependent on the Refractive Index (RI) and the difference in RI between the interface of the particle and the surrounding medium. For example, if the surrounding medium has an RI similar to that of the RI of the particle, then the mixture of the two materials will be more transparent. To illustrate, silica has an RI of about 1.5 and polymethylmethacrylate (EU) has an RI of about 1.5, so a coating comprised of nano silica and an pMMA will be nearly transparent. The properties of nanoparticles based on their dimension can be quite dramatic.
To read the full article written by Ron Lewarchik, Chemical Dynamics President, on UL Prospector, click here.
“For several years we have relied on the expertise of Chemical Dynamics to formulate new coatings products and solve problems. We would not hesitate to recommend Chemical Dynamics for formulating, evaluating and testing paint and raw materials.”
In recent years, there has been a growing interest in the use of bio-based resin building blocks in the synthesis of polymers for use in coatings. Bio-based products are derived from plants and other renewable agricultural, marine, and forestry materials and provide an alternative to conventional petroleum derived products.
Driving forces include a growing public and private awareness and interest in the use of renewable raw materials that can meet sustainability expectations and certifications such as Green Seal and Green Guard as well as the USDA BioPreferred Program for product labeling. Green Seal and Green Guard are environmentally driven, whereas the USDA BioPreferred Program functions to encourage the use of renewable agricultural raw materials in products. ASTM d6866 was developed to standardize, certify and classify the bio-based content of materials. Minimum renewable carbon content categories (MRCC) have been established for purchasing by Federal agencies and their contractors.
Table I – BioPreferred Coatings Categories[1]
Bio-based resins for coatings are normally referred to as alkyds (EU). Alkyds are comprised of fatty acid modified polyester resins. These resins are sometimes modified to include a urethane (EU) linkage and thus called uralkyds or oil modified urethanes. The fatty acid portion is derived from naturally occurring or renewable oils derived from sunflower (EU), safflower,soybean (EU), castor (EU), tall (EU) and others. Polyesters (EU) are derived from the reaction product of a polyol (EU) and a di or multifunctional acid or carboxylic acid and anhydride (EU) to form multiple ester linkages in a polymer chain.
To read the full article written by Ron Lewarchik, Chemical Dynamics President, on UL Prospector, click here.
Determining the effective cost of paint that can be made from naturally occurring elements involves several issues that must be considered. These include the volume solids of the paint, application method, and the geometry of the object to be painted. For example, a paint that sells for $20 per gallon at 20% volume solids is actually more expensive on an applied cost basis than a paint that sells for $40 per gallon at 45% volume solids.
Theoretical coverage |
= |
Volume Solids |
Dry mils required |
To illustrate the cost of paint to apply one mil (0.001 inch) per 100 square foot of the $20 paint is as follows:
To illustrate the cost of paint to apply one mil (0.001 inch) per 100 square foot of the $40 paint is as follows:
Accordingly, in this illustration, the $40 paint provides more value than the $20 paint as it provides lower cost coverage at equal dry film thickness. The table below illustrates paint coverage per mil for paint applied at 100% volume solids.
Theoretical coverage |
= |
Volume Solids |
Dry mils required |
US Patent 8,927,649 was awarded to Chemical Dynamics LLC on January 6, 2015. US Patent 8,927,649 covers of a film forming penetrant coating with a high cross-link density that arrests corrosion on rusty substrates.
Patent Abstract: A one part, storage stable polymerizable formulation is provided that includes an ethenically unsaturated polymerizable compound intermixed with a free radical polymerization initiator and an organic solvent. The organic solvent provides storage stability and upon evaporation of the solvent, the rate of polymerization of the compound accelerates independent of addition of a second part. The formulation includes at least 30 total weight percent solids upon cure. Optional additives to the formulation include at least one of a cure accelerator, a filler, a plasticizer, a colorant, and a cure inhibitor. A process for forming a polymerized coating on an article involves the application of this formulation to the substrate of an article and allowing sufficient time for the solvent to evaporate to form the polymerized coating on the article. The substrate of the article forms a corrosion barrier even without prior removal of a native corrosion layer on a surface of the substrate of the article.
SITUATION: A global company with multibillion dollar sales required a paint raw material evaluation from a paint expert of the performance and application potential of a new fluoropolymer resin that they developed.
ACTION: Due to the resident coating expertise in fluoropolymer coatings, the supplier contracted Chemical Dynamics to provide an independent evaluation of this new resin chemistry. Our company conducted paint and coatings testing to evaluate the material.
RESULT: Chemical Dynamics completed the evaluation and identified multiple new applications for the fluoropolymer resin chemistry.
Wood has been used as a building material for thousands of years due to its availability, low weight to strength ratio and, in many applications, high aesthetic quality. However, as a paintable substrate, it also provides some unique challenges and considerations, as wood is a dynamic, porous (cellular structure) and hygroscopic material. A few considerations include:
Table I – Percent Dimensional Change of Wood as Moisture Content Varies from 5 to 15%
For a 10 cm thick wood section, a fluctuation in Relative Humidity of about 10% means a change in a tangential longitudinal wood piece of 3.5 mm (or 3,500 microns). Accordingly, these relatively large dimensional changes produce cracks as the wood looses elasticity due to aging. Thus a properly designed wood coating must have the requisite flexibility to accommodate these dimensional changes without cracking. Wood is comprised of about 75% cellulose and hemicellulose and 25% lignin, resins and low molecular weight phenolics. In exterior applications, wood is susceptible to degradation and subsequent erosion due to exposure to UV degradation, oxygen, moisture and biological activity. When exposed to the elements, the lower molecular weight materials will degrade to form water-soluble compounds that wash out whereas the more stable cellulosic molecules remain to form a white-grey color.
To read the full article about Considerations for Developing Wood Coatings, click here.
Reactive silanes (EU) can be used in multiple applications to enhance the performance of coatings. They can improve adhesion to inorganic substrates, provide crosslinking, improve pigment dispersion, improve hydrophobicity and scavenge moisture. A silane (EU) that contains at least one carbon silicon bond (CH3 – Si -) is called an organosilane (EU).Reactive silane is the term used to define compounds that have a trialkoxysilyl group and an alkyl group (R) containing a reactive constituent.
The trialkoxy silanes that are discussed in this article are those that contain primarily trimethoxy (EU) groups, as these molecules are the most widely used to enhance coating performance in a wide variety of applications, as follows:
To read the full article about Reactive Silanes for Enhancement of Coating Performance, click here.
PROBLEM: A company with multibillion dollar sales to the automotive OEM market required a unique coating for markets around the globe and was unable to locate a paint company with the expertise to develop the requisite performance.
ACTION: They contacted the paint experts at Chemical Dynamics to develop a coating that would meet their performance needs of being REACH compliant, low VOC, low friction with resistant to high heat and automotive chemicals.
RESULT: It a short period of time, Chemical Dynamics was able to develop a product that met all customer requirements.
