Glass transition temp

Question 1

What is the Tg?

Answer 1

~ the temp at which the extrapolated temp at which glass stops contracting as a liquid and starts contracting as a solid

~ falls between annealing and strain points

Question 2

What effect does a fast quench have?

Answer 2

~ causes the room temp glass to have frozen-in, more open (liquid like) molar volume

Question 3

What effect does a slower coolong rate have?

Answer 3

~ lower Tg

Question 4

What happens when you reheat a borosilicate glass upon rapid quenching? Upon slow quenching?

Answer 4

rapid quench: it contracts before expanding like a liquid

slow: expands like liquid