Poly(propylene glycol) diglycidyl ether

Poly(propylene glycol) diglycidyl ether (PPGDGE) is an organic chemical in the glycidyl ether family. There are a number of variations depending on the starting molecular weight of the polypropylene glycol.^[1] They have the formula (C₃H₆O)_n.C₆H₁₀O₃^[2] and the IUPAC name is Poly[oxy(methyl-1,2-ethanediyl)],a-(2-oxiranylmethyl)-w-(2-oxiranylmethoxy)- ^[3] A key use is as a modifier for epoxy resins as a reactive diluent and flexibilizer.^[4][5] It is REACH registered.^[6]

Poly(propylene glycol) diglycidyl ether

Names
Other names Polyoxypropylene diglycidyl ether; PPGDGE
Identifiers
CAS Number	26142-30-3
ECHA InfoCard	100.130.913
CompTox Dashboard (EPA)	DTXSID00892240
Properties
Chemical formula	(C3H6O)n.C6H10O3
Molar mass	Variable
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Manufacturing

The product is made by taking polypropylene glycol and epichlorohydrin and reacting in the presence of a Lewis acid catalyst to form a halohydrin. The next step is dehydrochlorination with sodium hydroxide. This forms the diglycidyl ether. Waste products are sodium chloride, water and excess sodium hydroxide (alkaline brine).^[7][8] One of the quality control tests would involve measuring the epoxy value by determination of the epoxy equivalent weight.

Use

The molecule has 2 oxirane functionalities, and so a key use is modifying and reducing the viscosity of epoxy resins.^[9][10] These reactive diluent modified epoxy resins may then be further formulated into CASE applications: coatings,^[11] adhesives, sealants, and elastomers. It produces epoxy coatings with high impact resistance.^[12] The use of the diluent does effect mechanical properties and microstructure of epoxy resins.^[13]

Synthesis of waterborne polymers has been a feature with this substance. 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.^[14][15]

The material maybe used to produce polymers with shape memory and good thermomechanical properties.^[16] In addition, the molecule is used to synthesize other molecules.^{[17][18][19][20][21]}

Toxicology

The toxicology of the material is reasonably well known.^[22]

See also

• Epoxide
• Glycidol

Further reading

• Epoxy resin technology. Paul F. Bruins, Polytechnic Institute of Brooklyn. New York: Interscience Publishers. 1968. ISBN 0-470-11390-1. OCLC 182890.{{cite book}}: CS1 maint: others (link)
• Flick, Ernest W. (1993). Epoxy resins, curing agents, compounds, and modifiers : an industrial guide. Park Ridge, NJ. ISBN 978-0-8155-1708-5. OCLC 915134542.{{cite book}}: CS1 maint: location missing publisher (link)
• Lee, Henry (1967). Handbook of epoxy resins. Kris Neville ([2nd, expanded work] ed.). New York: McGraw-Hill. ISBN 0-07-036997-6. OCLC 311631322.
• "Dow Epoxy Resins" (PDF).