Additives, Modifiers & Solvents

Polymerization Applications

Catalyst Carriers and Reaction Diluents

High-purity hydrocarbons can be used as catalyst carriers or reaction diluents for polymer production. We offer high-purity hydrocarbons with a range of physical properties to meet the demands of almost any polymerization process, including polystyrene, HDPE, and LDPE. Our Soltrol® isoparaffin solvents can also find applications as reaction diluents or catalyst carriers in polyethylene manufacturing.

Chain Transfer Agents

The growth of free radically produced polymer chains can be controlled by adding small amounts of mercaptans as chain modifiers. Some examples of the various polymers made with mercaptan chain transfer agents are shown below.

Product Applications
n-dodecyl mercaptan & n-octyl mercaptan neoprene, polyacrylate resin (paint), polymethacrylate, and polystyrene
tert-dodecyl mercaptan styrene butadiene latex for rubber and paper coating, nitrile rubber, acrylonitrile butadiene styrene (ABS), and expandable polystyrene
2-mercaptoethanol water-soluble acrylic resins and special grades of polyvinyl chloride (PVC)
methyl 3-mercaptopropionate polymethacrylate

Usually the heavier mercaptans are used as chain modifiers in order to avoid excessive odor in the manufacturing process and in the final product.

Shortstoppers

DEHA (N,N-diethylhydroxylamine) is a widely used shortstopper for free radical polymerization. DEHA stops polymerization by capping the growing polymer chain with hydrogen. In the presence of water, DEHA can scavenge up to four radicals, and in the absence, can scavenge two. DEHA will not discolor the resulting polymer and can be water washed from the product. DEHA is also useful to inhibit popcorn polymer formation in styrene/butadiene monomer production or recovery.

Additives

Antioxidants and other stabilizers are added to polymers during processing.  Some specific examples involving the use of mercaptans and amines include:

Product Applications
n-alkyl mercaptans reagents used in antioxidant synthesis
cyclohexyl mercaptan produces an additive that prevents the charring of rubber during vulcanization
mercaptans epoxy curing agents
2-mercaptoethanol & long-chain mercaptopropionates produce PVC stabilizers