Glacial Acrylic Acid Monomer (GAA) is an unsaturated carboxylic acid co-monomer used as a building block to produced acid functional and crosslinked acrylic copolymers and polyacrylic acids. GAA readily copolymerizes with acrylic and methacrylic esters, ethylene, vinyl acetate, styrene, butadiene, acrylonitrile, maleic esters, vinyl chloride and vinylidene chloride. Copolymers which contain GAA can be solubilized or exhibit improved dispersions in water; the carboxylic acid moiety can be used for coupling or crosslinking reactions, and improved adhesion. GAA copolymers are used in the form of their free acid, ammonium salts or alkali salts. These polymeric uses for GAA account for approximately 45 % of the consumption of acrylic acid monomer (the manufacture of acrylate esters is the other major use).GAA has the chemical structure shown below.
Glacial acrylic acid does not contain water and freezes at 13°C (55°F).
Gantrade sells inhibited Glacial Acrylic Acid in 200 Kg. drums and in tank trucks, with the following specifications:
Appearance at 25 °C: Clear, colorless liquid
Purity by GC, % > 99.0
Color, APHA < 10
Moisture weight % by K.F. < 0.20
ppm MEHQ 180 – 220
Homopolymers of acrylic acid and copolymers which contain a preponderance of acrylic acid are frequently soluble in water. Glacial Acrylic Acid offers significant advantages as a co-monomer in a wide range of acrylic and vinyl acrylic polymer-based finishes, coatings, adhesives, sealants, finishes, inks, flocculants, thickeners, dispersing agent, lubricants, saturants and plastics. Other copolymer uses of GAA, especially with acrylamide co-monomer, include oil-field drilling fluids, fracking systems, mining processing chemicals, detergent builders, water treatment chemicals and superabsorbent materials (SAPs).
Acrylic co-polymer emulsions and dispersions produced using GAA to introduce a number of attributes as delineated below:
Benefits of the GAA Functionaility:
- Improved adhesion to polar surfaces & fillers – increasing the GAA contnt will increase adhesive properties
- Toughness & tensile properties through hydrogen bonding
Co-monomers for acrylic polymer emulsions include butyl acrylate (BA), 2-ethylhexyl acrylate (2-EHA), methyl and ethyl acrylate (MA & EA) and methyl methacrylate (MMA).. By selecting the appropriate Tg’s of the monomer building-blocks, polymers with specific attributes for a wide variety of end-use applications can be built.
An increase in durability, moisture and chemical resistance can be attained by crosslinking all or a portion of the available carboxylic acid moieties in GAA co-polymers. A delineation of crosslinking agents for the carboxylic acid moiety is provided below. Melamine-formaldehyde resins are particularly effective in crosslinking.
- Melamine formaldehyde crosslinking agents
- Urea formaldehyde crosslinking agents
- Phenol formaldehyde resins
- Epoxy resins
- Multi-valent ionic metal complexes like zinc, aluminum and zirconium
Organofunctional silanes can be used to modify GAA copolymers to enhance adhesion to surfaces like glass, glass fibers, metals, silica and other mineral fillers, and concrete. Silane modified acrylic copolymers also improves the compatibility and dispersability of fillers in a polymer matrix.
The most common organofunctional silanes used to modify GAA copolymers are the aminosilanes like 3-(aminopropyl)triethoxysilane (A-1100 silane) and glycidyl silanes such as 3-(glycidoxypropyl)trimethoxysilane (A-187 silane). Addition levels are about 0.2-0.5% based on the copolymer. The silane adhesion promoter acts as a strong molecular bridge between chemically different materials. The performance benefits of silanes are delineated below.
Silanes adhison promoter benefits:
- Improved adhesion, wet and dry
- Increased moisture and solvent resistance
- Improved wetting of fillers and surfaces; improved filler dispersion
- Improved mechanical properties;
Gantrade offers Glacial Acrylic Acid in stainless steel drums with a net weight of 450 lbs. and in Tank Trucks.