Bis-HPPP

Bis-HPPP (2,2-bis[4(2,3-hydroxypropoxy)phenyl]propane) is an organic compound that is formed when the dental composite material bis-GMA is degraded by salivary esterases.^[1] It is also called BADGE·2H₂O in reference to it being the hydrolyzed form of BADGE, which is used in the formation of epoxy resins.^[2] Structurally, it is a di-ether of bisphenol A.

Bis-HPPP

Names
Preferred IUPAC name 3,3′-[Propane-2,2-diylbis(4,1-phenyleneoxy)]di(propane-1,2-diol)
Other names BADGE·2H2O
Identifiers
CAS Number	5581-32-8
3D model (JSmol)	Interactive image
ChemSpider	99341 N
ECHA InfoCard	100.024.524
PubChem CID	110678
UNII	S5K2510L3D Y
CompTox Dashboard (EPA)	DTXSID10971212
InChI InChI=1S/C21H28O6/c1-21(2,15-3-7-19(8-4-15)26-13-17(24)11-22)16-5-9-20(10-6-16)27-14-18(25)12-23/h3-10,17-18,22-25H,11-14H2,1-2H3 N Key: NISVZEWKUNUGQQ-UHFFFAOYSA-N N InChI=1/C21H28O6/c1-21(2,15-3-7-19(8-4-15)26-13-17(24)11-22)16-5-9-20(10-6-16)27-14-18(25)12-23/h3-10,17-18,22-25H,11-14H2,1-2H3 Key: NISVZEWKUNUGQQ-UHFFFAOYAT
SMILES OCC(O)COc1ccc(cc1)C(C)(C)c2ccc(OCC(O)CO)cc2
Properties
Chemical formula	C21H28O6
Molar mass	376.449 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Formation

Together with methacrylic acid, bis-HPPP is released following the CE-catalyzed^{[clarification needed]} hydrolysis of 2,2-[4(2-hydroxy 3-methacryloxypropoxy)-phenyl]propane (bis-GMA). This reaction is very common in hydrolytic degradation of the dental resin since salivary esterases are able to cleave the ester bonds in acrylic polymers of dental composites.

Analysis by mass spectrometry demonstrated that hydrolytic reactions would cleave the ester bonds of both methacrylate units in bis-GMA and produce bis-HPPP along with two molecules of methacrylic acid.^[3]