Physical world and mathematics

Polymerization

Polymerization, also called polymerise, is the chemical process in which monomers bond repeatedly into macromolecules, proceeding by chain or step growth in processes such as bulk and emulsion polymerization.

Polymerization-induced phase separation

Polymerization-induced phase separation (PIPS) is a fabrication method in which polymerization drives a homogeneous resin to separate into phases, used in liquid crystal displays and battery separators.

Polymerization-induced self-assembly

Polymerization-induced self-assembly (PISA) is a one-pot method, first reported in 2002, in which growing insoluble polymer blocks self-assemble in situ into block copolymer nanoparticles, reaching up to 50% solids without post-purification.

Polymetallic nodule

A polymetallic nodule, or manganese nodule, is a rock concretion on the deep ocean floor, rich in manganese, iron, nickel, copper, and cobalt, and targeted for deep-sea mining.

Polymethylhydrosiloxane

Polymethylhydrosiloxane (PMHS) is a linear silicone polymer, sold as a colorless liquid, used in organic synthesis as a mild, inexpensive hydride donor for metal-catalyzed reductions.

Polymyxin B

Polymyxin B is a lipopeptide antibiotic produced by the soil bacterium Paenibacillus polymyxa, discovered in 1947 and used as a last-line treatment for multidrug-resistant Gram-negative infections.

Polynomial

A polynomial is a mathematical expression built from powers of one or more variables multiplied by coefficients, forming the basic object of algebra and a key tool in cryptography and numerical analysis.

Polynomial chaos

Polynomial chaos is an uncertainty quantification method that represents a random model output as a series of orthogonal polynomials of the input random variables, originating in Norbert Wiener's 1938 work.

Polynomial chaos expansion

Polynomial chaos expansion (PCE) is an uncertainty quantification method that represents a model's output as a series of orthogonal polynomials in random inputs, introduced by Norbert Wiener in 1938.

Polynomial hierarchy

The polynomial hierarchy (PH) is a tower of complexity classes between P and PSPACE whose levels use a constant number of alternating quantifiers; whether it is infinite remains open.

Polynomial long division

Polynomial long division, also known as the polynomial division algorithm, divides one polynomial by another to produce a quotient and a remainder, like arithmetic long division.

Polynomial method

The polynomial method is a collection of techniques in combinatorics and number theory that controls finite sets of points with suitably chosen polynomials, emerging in the late 2000s.

Polynomial regression

Polynomial regression is a form of regression analysis that models a response as a polynomial in the predictors, fitted by least squares like ordinary linear regression.

Polynomial ring

A polynomial ring, also called a polynomial algebra, is a ring whose elements are polynomials in one or more indeterminates, written R[x] over a base ring R.

Polynomial Szemerédi theorem

The polynomial Szemerédi theorem is a result in additive combinatorics, proved by Bergelson and Leibman in 1996, extending Szemerédi's theorem to polynomial patterns in dense integer sets.

Polynomial transformation (statistics)

A polynomial transformation adds powers and cross-products of existing predictors as new features, so a linear regression model can represent curved relationships while remaining linear in its coefficients.

Polynomial-time approximation scheme

A polynomial-time approximation scheme (PTAS) is an algorithmic framework for NP-hard optimization problems that, given an accuracy parameter ε, returns a solution within a factor of the optimum in polynomial time.

Polynya (полынья)

A polynya (полынья), from Russian, is an opening of persistent or recurring open water within sea ice; coastal polynyas produce about 10% of Antarctic sea ice.

Polyol

A polyol is an organic compound carrying more than one hydroxyl group, a term covering sugar alcohol sweeteners like sorbitol and the industrial polyols used to make polyurethanes.

Polyol method

The polyol method, or polyol process, is a wet-chemical synthesis in which a heated polyol acts as solvent, reducing agent, and stabilizer, yielding metal and oxide nanoparticles.

Polyol synthesis

Polyol synthesis is a chemical method that reduces metal salts dissolved in a heated polyol to produce metal and metal oxide nanoparticles of controlled size, shape, and composition.

Polyolefin

A polyolefin, also called a polyalkene, is a polymer prepared from an olefin such as ethylene or propylene; polyethylene and polypropylene together make up over half of global plastic production.

Polyolefin metathesis

Polyolefin metathesis is a metal-catalyzed method that cleaves and rebuilds the backbones of polyolefin plastics such as polyethylene and polypropylene, upcycling them into fuels or propylene.

Polyolefin vitrimer

A polyolefin vitrimer is a cross-linked network of polyolefin chains, such as polyethylene or polypropylene, joined by dynamic covalent bonds that let the thermoset-like material be reprocessed and recycled above a temperature threshold.

Polyorthoester

Polyorthoesters, also known as poly(ortho esters) or POEs, are synthetic biodegradable polymers developed since 1970 whose surface erosion releases incorporated drugs at a roughly constant rate.

Polyoxetane

Polyoxetane is a polyether whose backbone consists of repeating trimethylene oxide units, made by ring-opening polymerization of oxetane and used in energetic propellant binders and lithium battery electrolytes.

Polyoxometalate water oxidation catalysis

Polyoxometalate water oxidation catalysis is the use of polyoxometalates, anionic metal-oxo clusters of tungsten, molybdenum, or vanadium, to catalyze water oxidation into oxygen, a field begun in 2008 with ruthenium-substituted polyoxotungstates.

Oct 20, 2026

Polyoxyethanyl-alpha-tocopheryl sebacate

Polyoxyethanyl-alpha-tocopheryl sebacate (PTS), CAS 263015-34-5, a vitamin E-derived nonionic micelle-forming surfactant; GRAS (GRN 202, Zymes LLC, 2006) as a coenzyme Q10 solubilizer in dietary supplements.

Polyoxymethylene

Polyoxymethylene, also called polyacetal, acetal, or polyformaldehyde, is a crystalline engineering thermoplastic made from formaldehyde, with metal-like hardness and low friction that make it a standard metal-replacement material in cars, electronics, and machinery.