About 40 million tons of PVC are produced each year. PVC comes in rigid (sometimes abbreviated as RPVC) and flexible forms. Rigid PVC is used in construction for pipe, doors and windows. It is also used in making plastic bottles, packaging, and bank or membership cards. Adding plasticizers makes PVC softer and more flexible.
- 1.4 g/cm³
Polyethylene terephthalate (or poly (ethylene terephthalate), PET, PETE, or the obsolete PETP or PET-P ), is the most common thermoplastic polymer resin of the polyester family and is used in fibres for clothing, containers for liquids and foods, and thermoforming for manufacturing, and in combination with glass fibre for engineering resins. 
- 10–50 kg/mol, varies
- > 250 °C (482 °F; 523 K) 260 °C
- Practically insoluble
Greenhouse gases are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. What distinguishes them from other gases is that they absorb the wavelengths of radiation that a planet emits, resulting in the greenhouse effect. 
Infrastructure - Wikipedia Infrastructure San Francisco Ferry Building at night Infrastructure is the set of facilities and systems that serve a country, city, or other area,  and encompasses the services and facilities necessary for its economy, households and firms to function. 
Helium (from Greek: ἥλιος, romanized: helios, lit. 'sun') is a chemical element; it has symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling point is the lowest among all the elements, and it does not have a melting point at standard pressures.
Production Industrial routes Ethylene glycol is produced from ethylene (ethene), via the intermediate ethylene oxide. Ethylene oxide reacts with water to produce ethylene glycol according to the chemical equation : C2H4O + H2O → HO−CH2CH2−OH
Properties Liquid NH 3 Solid NH 3 Two visible states of NH 3 Ammonia is a colourless gas with a characteristically pungent smell. It is lighter than air, its density being 0.589 times that of air. It is easily liquefied due to the strong hydrogen bonding between molecules.