EVAPORATIVE DYNAMIC OSCILLATION (EDOT)

Evaporative Dynamic Oscillation (EDOT) is an exciting and novel methodology that allows evaluation of evolution of rheological properties of polymers/coatings as the sample dries and cures as a function of time and/or temperature.
EDOT quantitatively characterizes the dry and cure profile of paints, coatings, and adhesives throughout the entire dry and cure regime, from application through complete cure at essentially any time/temperature profile, including if desired, aging effects. Further, EDOT allows one the ability to evaluate film properties in-situ such as modulus, glass transition temperature, stiffness, shrinkage, creep, and compliance, for example. Using EDOT, a scientist may quantitatively assess the impact of polymer composition, molecular weight, formulation constituents, as well as pigmentation effects on coating properties. EDOT is a powerful methodology for characterizing neat polymer properties as well, even if solvent is originally present in the sample.

Measurement Principle

The EDOT measuring principle is based upon performing a dynamic oscillation test on a polymer or coating film as the film dries under nearly free evaporative conditions utilizing a novel patent-pending test probe attached to an analytical rheometer operated in dynamic oscillation mode.
 
​The dynamic oscillation test is performed within the sample’s linear viscoelastic region (e.g., under extremely low strains) so as to not disrupt the sample’s internal structure; hence, measurements are performed on the sample while it is “at rest.”
 
Thus EDOT yields information regarding a sample's elastic and loss modulus as well as its complex viscosity as a function of time and/or temperature. Because the sample is evaluated in a state of rest, complex viscosity results approach zero shear viscosity.

Benefits

• Easy Sample preparation
  
• Quantitative data 
  
• Comprehensive polymer and coating analysis
  
• Repeat-able results
• Tailored cure profile

The unique and novel design of the EDOT measuring system gives rise to this system closely approaching the characteristics of an ideal measuring system. 

Types of Samples Evaluated

 The types of samples that may be evaluated by EDOT include, but are not limited to:
solvent and water based polymers

• Organic Coatings
• Water Based Coatings
• Adhesives

Technologies include thermoplastic coatings such as:

• Acrylic Polymers
• Nitrocellulose Lacquers
• Cellulose Esters
• Hard Resin Modifiers, etc.

Also, Thermoset Coatings such as:

• Epoxies
• Acid Catalyzed Alkyd Amino Coatings
• 2K Polyurethanes, etc.

Coatings that cure by oxidative mechanisms may be evaluated as well. Clear coatings as well as pigmented coatings may be evaluated.

A Wider Scope 

EDOT is a quantitative method for assessing dry and cure of materials and is far superior to other dry time methods such as a dry time recorders, and allows one to assess the dry and cure of a film at any  given time stamp within the testing protocol. EDOT allows assessment of thermoplastic as well as thermoset compositions; water based, solvent based compositions, as well as water based and solvent based UV technology. The methodology allows determination of rate of cure and degree of cure of crosslinking compositions and is also useful for study of impact of various catalysts on such systems.
Further, EDOT is extremely useful for study of impact of rheological additives on coating films as the coating is drying and for assessment of film formation of various filming aids

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