Polypropylene glycolorpolypropylene oxide is the polymer (or macromolecule) of propylene glycol.[1] Chemically it is a polyether, and, more generally speaking, it's a polyalkylene glycol (PAG) H S Code 3907.2000. The term polypropylene glycol or PPG is reserved for polymer of low- to medium-range molar mass when the nature of the end-group, which is usually a hydroxyl group, still matters. The term "oxide" is used for high-molar-mass polymer when end-groups no longer affect polymer properties. Between 60 and 70% of propylene oxide is converted to polyether polyols by the process called alkoxylation.[2]
PPG has many properties in common with polyethylene glycol. The polymer is a liquid at room temperature. Solubility in water decreases rapidly with increasing molar mass. Secondary hydroxyl groups in PPG are less reactive than primary hydroxyl groups in polyethylene glycol. PPG is less toxic than PEG, so biotechnologicals are now mainly produced with PPG.[4][5][6]
Difference in water solubility of PPG4000 and PPG400
PPG is used in many polyurethane formulations.[7][8] Synthesis of waterborne polymers has been a feature with this substance.[9] As the basic building block is propylene oxide, there are 3 carbons per oxygen on the backbone. This confers some degree of water miscibility though not as good as ethylene oxide based molecules.[10] It is used to synthesize the epoxyreactive diluent and flexibilizer, Poly(propylene glycol) diglycidyl ether.[11][12] Another use of PPG is as a surfactant, wetting agent and dispersant in leather finishing.[13] PPG is also employed as a reference and calibrant in mass spectrometry and HPLC.[14][15] PPG and derivatives may be used as defoamers in drilling and other applications.[16][17] It is also used as a primary ingredient in the making of paintballs.[18] It has been evaluated as a corrosion inhibitor.[19]
^Thangavelu SA, Mukherjee M, Layana K, Kumar CD, Sulthana YR, Kumar RR, et al. (2020-06-15). "Biodegradable polyurethanes foam and foam fullerenes nanocomposite strips by one-shot moulding: Physicochemical and mechanical properties". Materials Science in Semiconductor Processing. 112: 105018. doi:10.1016/j.mssp.2020.105018. ISSN1369-8001. S2CID213206957.
^Chattopadhyay DK, Raju NP, Vairamani M, Raju KV (2008-04-01). "Structural investigations of polypropylene glycol (PPG) and isophorone diisocyanate (IPDI) based polyurethane prepolymer by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF)-mass spectrometry". Progress in Organic Coatings. 62 (2): 117–122. doi:10.1016/j.porgcoat.2007.09.021. ISSN0300-9440.
^Xu Z, Cui Y, Li T, Dang H, Li J, Cheng F (July 2020). "Enhanced Mechanical and Shape Memory Properties of Poly(propylene glycol)‐Based Star‐Shaped Polyurethane". Macromolecular Chemistry and Physics. 221 (13): 2000082. doi:10.1002/macp.202000082. ISSN1022-1352. S2CID225563251.
^US 10920011, Kim KJ, Hu R, Grove JL, "Water soluble polymers and polymer adducts along with aqueous solutions thereof Patent", issued 16 February 2021, assigned to Arkema Inc
^Howarth GA (April 1997). Synthesis of a legislation compliant corrosion protection coating system based on urethane, oxazolidine and waterborne epoxy technology (Master of Science thesis). London: Imperial College. pp. 36–28, 52–60.
^Rychłowska J, Zgoła A, Grześkowiak T, Lukaszewski Z (December 2003). "Isolation of poly(propylene glycol)s from water for quantitative analysis by reversed-phase liquid chromatography". Journal of Chromatography A. 1021 (1–2): 11–17. doi:10.1016/j.chroma.2003.09.003. PMID14735971.
^Solomon MM, Umoren SA, Israel AU, Etim IG (January 2016). "Synergistic inhibition of aluminium corrosion in H2SO4 solution by polypropylene glycol in the presence of iodide ions". Pigment & Resin Technology. 45 (4): 280–293. doi:10.1108/PRT-01-2015-0010. ISSN0369-9420.
