* Silicon dioxide (SiO2): The main component, providing the basic glass structure.
* Boron trioxide (B2O3): This is what gives borosilicate its special properties, like resistance to thermal shock and chemical attack.
* Sodium oxide (Na2O) and/or Potassium oxide (K2O): These are fluxing agents, lowering the melting point of the glass and making it easier to work with.
Commonly used borosilicate glass compositions:
* Pyrex: 80% SiO2, 13% B2O3, 4% Na2O, 3% Al2O3
* Schott Duran: 78% SiO2, 12% B2O3, 5% Na2O, 5% Al2O3
The exact proportions of these oxides vary depending on the specific type of borosilicate glass and its intended application.
Therefore, there's no single chemical formula for borosilicate. It's a glass system, with a range of compositions within a specified range.
