Difference between revisions of "Additive (adhesives, paints, and plastic)"
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== Description == | == 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 | + | 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 change the performance (flexibility, UV resistance, etc.) or appearance (color, opacity, etc.) of the pure polymer. Plastics, adhesives, and paints often contain around 20 additives, most of which are unlisted components because they are considered trade secrets. This in effect conceals any and all toxicity interactions to humans and the environment. A secondary complication is that some of the additives are weakly bound to the polymeric matrix which can lead to separation and/or degradation. The combination of these factors means that additives have to potential to create problems in all stages of a plastics lifecycle, including preparation, handling, lifetime use, and waste disposal. |
Examples of additives include: | Examples of additives include: | ||
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| Also called stabilizer. Phenols, phosphite esters, some thioethers | | Also called stabilizer. Phenols, phosphite esters, some thioethers | ||
| Almost all plastics with contains some type of stabilizers | | Almost all plastics with contains some type of stabilizers | ||
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| Antiskin agent | | Antiskin agent | ||
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| [[thickening%20agent|Thickener]] | | [[thickening%20agent|Thickener]] | ||
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| − | | | + | | Used to prevent the sagging of a coating |
| − | | | + | | Also called anti-sag agent |
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Revision as of 13:07, 4 June 2023
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 change the performance (flexibility, UV resistance, etc.) or appearance (color, opacity, etc.) of the pure polymer. Plastics, adhesives, and paints often contain around 20 additives, most of which are unlisted components because they are considered trade secrets. This in effect conceals any and all toxicity interactions to humans and the environment. A secondary complication is that some of the additives are weakly bound to the polymeric matrix which can lead to separation and/or degradation. The combination of these factors means that additives have to potential to create problems in all stages of a plastics lifecycle, including preparation, handling, lifetime use, and waste disposal.
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 |
| 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 | Used to prevent the sagging of a coating | Also called anti-sag agent |
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)