why the glue hardens when it is squeezed from the tube.
2006-06-26 00:53:30 · 7 answers · asked by ghulamalimurtaza 3 in Science & Mathematics ➔ Chemistry
Glue is typically a solid dissolved in an easily evaporated solvent. When it hits the air, the solvent evaporates. Typical solvents used are water and xylene. When the solvent evaporates, the solid material reverts back into being a solid.
2006-06-26 00:59:46 · answer #1 · answered by Huey from Ohio 4 · 0⤊ 0⤋
The glue hardens when it is exposed to air - usually when the water evaporates b (but not always). So that's what happens, it dries out - the moisture in the glue is absorped by the air and the glue sets hard.
2006-06-26 08:03:24 · answer #2 · answered by Andale, pues 2 · 0⤊ 0⤋
The glue starts to harden when it comes in touch with the atmospheric Oxygen and moisture which starts the glue to set .While inside the tube this reation can't happen so it remains liquid.
2006-06-26 07:58:13 · answer #3 · answered by sudiptocool 2 · 0⤊ 0⤋
In solvent based glue the solvent evaporates and the polymer hardens, in water based glue the water dries out and the glue base hardens.
2006-06-26 08:00:47 · answer #4 · answered by Robert L 1 · 0⤊ 0⤋
do you mean while you are attempting to squeeeze it out? or afterwards, when it dries? if you mean the former, then it is because you are pushing the particles closr together and the resistence from the tube makes it lightly difficult to get out.
if you mean the latter, then that is because the glue contains water usually, and his water evaporates over time, making the glue then harden.
2006-06-26 08:00:39 · answer #5 · answered by kaztacular 2 · 0⤊ 0⤋
the water in it evaporates when it has greater air exposure. It hardens.
2006-06-26 07:56:14 · answer #6 · answered by alannabear34 2 · 0⤊ 0⤋
because it hits the oxygen.
2006-06-26 07:56:39 · answer #7 · answered by mchlmaiorana 2 · 0⤊ 0⤋