Why Mfft is lower than Tg?
Why Mfft is lower than Tg?
Efficiency of Coalescing Agents in Film Formation Process It reduces the Tg of water-based coatings below the minimum film-formation temperature (MFFT). The CA-lowered T, of the polymer gives the reduced MFT of the dispersion, which allows film formation at lower temperatures.
How do you find the minimum film forming temperature?
The minimum film-forming temperature (MFFT) of a paint or coating is the lowest temperature at which it will uniformly coalesce when laid on a substrate as a thin film. The standard test for determining this temperature involves using a MFFT-BAR, as specified by such standards as ASTM D 2354 and ISO 2115.
What is a coalescing agent?
What is a Coalescing Agent? A coalescing agent’s primary role is to soften the polymer, allowing a solid uniform continuous film as the paint dries. It acts as a stabilizer or a temporary plasticizer that provides an even dispersion for the polymer or the resin.
What is glass transition temperature in polymers?
The glass transition temperature is the temperature range where the polymer substrate changes from a rigid glassy material to a soft (not melted) material, and is usually measured in terms of the stiffness, or modulus.
What is meant by glass transition?
The glass transition is the phenomenon in which a solid amorphous phase exhibits more or less abrupt changes in derivative thermodynamic properties such as heat capacity or thermal expansion: when an amorphous material changes from a solid state to a liquid state on heating or from a liquid to a solid-like state on …
Is texanol a VOC?
With a boiling point of 254°C, (vapor pressure 0.01 kPa @ 20°C), Eastman Texanol ester alcohol is not classified as a VOC according to European Union Decopaint Directive 2004/42/EC (commonly referred to as the Decopaint Directive); European Union Solvent Emissions Directive); and the China State Environmental …
What is a coalescent in paint?
Page Content. Eastman coalescents enable maximum film formation in latex paints, often improving overall paint performance. Coalescent works by softening the latex particles, allowing them to fuse into a tough, continuous film. Common coalescents include ester alcohols, esters, and glycol ethers.
What is the difference between Tg and TM?
The terms TG (or Tg) and TM (or Tm) give two important parameters of polymers. These are temperatures at which the texture of polymer changes. These values are characteristic features of polymers. TG refers to the glass transition temperature whereas TM refers to the melting temperature.
