Additive (adhesives, paints, and plastic)

Description

In terms of polymers or paints, an additive is a chemical substance, usually in small quantities, that is added to a base material for the purpose of modifying the properties of the end product. Additives an change the performance (flexibility, UV resistance, etc.) or appearance ( color, opacity, etc.). Plastics and paints often contain around 20 additives, most of which are unlisted components considered trade secrets. As such, their toxicity to humans and the environment is often unknown. Some of the additives are weakly bound to the polymeric matrix which can lead to separation and/or degradation.

Examples of additives include:

Additive Type	Typical concentration (%)	Description	Example compounds	Comments
Accelerator	0-50	Increases the reaction rate of polymerization and decrease storage life, working life, gel time, etc.; also called curing agent, hardener, promoter and vulcanizer (for rubber)	Used for polyesters (styrene), rubbers (sulfur compounds), along with some activators (peroxide, zinc oxide, diamines, stearic acid, etc.)	Incorrect proportions and poor mixing will weaken the polymer structure
Adhesion promoter		tackifier
Antioxidant	0.5-3.0	Protects against degradation, especially during processing	Also called stabilizer. Phenols, phosphite esters, some thioethers	Almost all plastics with contains some type of stabilizers
Antisag agent
Antiskin agent
Antistatic agent
Biocide		Designed to destroy, deter, or control degradation from harmful organisms; also called antimicrobial	Generally poisonous substances including preservatives, insecticides, disinfectants and pesticides	Present in small amounts but quite toxic
Blowing agent
Clarifying agent
Coalescing agent
Colorant	0.001- 10	Used to give color or opacity	Any Dye or Pigment
Defoaming agent
Dispersant
Drier
Emulsifier
Filler	0-50	Also called bulking agents. they change the mechanical and optical properties, while producing a less expensive product	Talc, Chalk, Glass bead, Glass fiber, Carbon black, Carbon fiber	Most polymers contain fillers. High level protect against UV rays
Flame retardant	1-30	Used to minimize burning	Most commonly used are brominated and chlorinated paraffins, aluminum hydroxide, antimony trioxide and various organophosphates	Non-chlorinated organophosphates are safer but do not work as well
Heat stabilizer	0.3-5	Minimizes degradation due to heat exposure; also called thermal stabilizer	Formerly derivatives of Lead, Tin and Cadmium were used. Alternatives are barium/zinc mixtures and calcium stearates	Primarily used in PVC which is prone to thermal degradation
Impact modifier	10-40	Improved toughness and resistance to damage	Usually an elastomeric copolymer such as butadiene, styrene, etc.	Chlorinated polyethylene is used for PVC
Light stabilizer	0.05-3	Protects against UV damage by absorbing or quenching UV rays	HALS (of ten used n polyolefins, polyethylene, polyurethane), UV blockers (such as benzotriazoles) and quenchers (usually a dye)	Normally only used in products designed for outdoor use
Lubricant	0.1-3	Used to assist in the process of forming/molding plastic; also called release agents and slip agents	PFASs (hazardous), Paraffin wax, wax ester, metal stearates (Zinc stearate, etc.), fatty acid amides (oleamide, erucamide, etc.)
Plasticizer	10-70	Provide flexibility	Phthalates are most common followed by adipate ester and citrate esters	PVCs use the most plasticizers followed by cellulose acetate. Phthalates leach out with time and are considered carcinogenic
Size
Thickener

Synonyms and Related Terms

additives (pl.); modifier; admixture; Additive (Deut.); additif (Fr.); aditivo (Port.)

Resources and Citations

• Monona Rossol, 'Water-Based Latex Paints'
• Theodore J. Reinhart, 'Glossary of Terms', '2019 NYCOSH webinar on paints handout, Engineered Plastics, ASM International, 1988
• ASTM, "Standard Terminology Relating to Paint, Varnish, Lacquer and Related Products", Annual Book of ASTM Standards, Section 6, Paints, Related Coatings and Aromatics, ASTM, D16, 7-Jan, Jul-96
• Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982
• Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000
• Wikipedia: http://en.wikipedia.org/wiki/Additive (Accessed Feb. 2, 2006)
• Wikipedia: |Plastic Additives (Accessed June 2023)