Reactive Group Datasheet

Acrylates and Acrylic Acids

Many of the acrylate esters, e.g. methyl methacrylate, have relatively high vapor pressures and are highly flammable, with flash points below 100 deg C.
Acrylic acid and its esters readily combine with themselves (to form polyacrylic acid) or other monomers (e.g. acrylamides, acrylonitrile, vinyl, styrene, and butadiene) by reacting at their double bond, forming homopolymers or copolymers.

These materials are capable of thermally induced or chemically initiated radical type polymerization reactions which can generate significant amounts of heat (up to -100 kJ/mol). This can result in large adiabatic temperature rises, which also can trigger gassy decomposition reactions.

These materials are typically inhibited with low levels (ppm range) of antioxidants to prevent premature polymerization chain reactions and these inhibitors may require dissolved oxygen to be effective. The inhibitors can be depleted with time and are depleted faster at higher storage temperatures. These materials are known to be susceptible to destabilization due to contaminants, even at low levels of contamination. Although there are obvious contaminants that are known to possibly be immediately initiatory to the monomer (radical generating species such as peroxides, azides, etc.), other effects on stability from even seemingly benign materials are harder to predict. Therefore extreme caution should be used in any contamination event and the material should be presumed to be destabilized until testing and consultation with experts occurs and determines otherwise. If the inhibitor and inhibition mechanism are compromised via some interaction with the contaminant, the monomer may polymerize and if contained in a storage container at relatively large volume, the system may become adiabatic and lead to a serious runaway reaction with high temperatures and pressures. The general hazards of monomers are discussed in Frurip et al., Process Safety Progress (Vol. 14, No. 2) 1995.
Many of the esters in this group have low to moderate toxicity. The main health concern is respiration exposure.
Other Characteristics
The acrylate ion [CH2=CHCOO]- is the conjugate base of acrylic acid. Acrylates are the salts and esters of acrylic acid. They are also known as propenoates (since acrylic acid is also known as 2-propenoic acid). Acrylates contain vinyl groups, that is, two carbon atoms double bonded to each other, directly attached to the carbonyl carbon. Acrylates and methacrylates (the salts and esters of methacrylic acid) are common monomers in polymer plastics and are also used in the manufacture of various coatings, adhesives, elastomers, as well as floor polishes, and paints.
Acrylamide, butyl acrylate, isodecyl acrylate, methacrylic acid, pentaerythritol triacrylate, sodium acrylate, methyl methacrylate.