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Phthalates (US: / ˈ θ æ l eɪ t s / UK: / ˈ (f) θ æ l eɪ t s ˌ ˈ (f) θ æ l ɪ t s / [1] [2]), or phthalate esters, are esters of phthalic acid. They are mainly used as plasticizers , i.e., substances added to plastics to increase their flexibility, transparency, durability, and longevity.
The negative charges create a repulsion that causes the polymer to swell. This swelling behavior is observed when the pH is greater than the pKa of the polymer. [2] Examples include polymethyl methacrylate polymers (pharmacologyonline 1 (2011)152-164) and cellulose acetate phthalate.
Polyvinyl acetate phthalate (PVAP) is a commonly used polymer phthalate in the formulation of pharmaceuticals, such as the enteric coating of tablets or capsules. It is a vinyl acetate polymer that is partially hydrolyzed and then esterified with phthalic acid. Its main use in pharmaceutics is with enteric formulations and controlled release ...
[citation needed] Polyester makes up about 18% of world polymer production and is the fourth-most-produced polymer after polyethylene (PE), polypropylene (PP) and polyvinyl chloride (PVC). [citation needed] PET consists of repeating (C 10 H 8 O 4) units. PET is commonly recycled, and has the digit 1 (♳) as its resin identification code (RIC).
Phthalates are contained in plastics at high percentages. For example, they can contribute up to 40% by weight to intravenous medical bags and up to 80% by weight in medical tubing. [ 49 ] Vinyl products are pervasive—including toys, [ 50 ] car interiors, shower curtains, and flooring—and initially release chemical gases into the air.
Bis(2-ethylhexyl) phthalate (DEHP) also commonly known as (dioctyl phthalate, [12] DOP or diethylhexyl phthalate), historically used in flooring materials, medical devices, myriad consumer products, and high explosives, such as Semtex. DEHP was the most common plasticizer for decades and still holds that title globally even as it has largely ...
Cellulose acetate phthalate (CAP), also known as cellacefate and cellulosi acetas phthalas, is a commonly used polymer phthalate in the formulation of pharmaceuticals, such as the enteric coating of tablets or capsules and for controlled release formulations.
Polybutylene terephthalate (PBT) is a thermoplastic engineering polymer that is used as an insulator in the electrical and electronics industries. [2] It is a thermoplastic (semi-)crystalline polymer, and a type of polyester.