A high temperature glue is for knives that will go into a dishwasher, not for too hot grinding temps. What kind of a grinding grit are you using on your angle grinder? I use an angle grinder to take down metal sometimes, but rarely on handles except maybe an axe handle.
I use a 4 1/2 grinder and will use 60-80-100-120 grit sanding pads. Change the pads often and you will have to finish by hand as any higher grit on a small 4 1/2 pad will clog up fast if you glue a finer grit on there. I've done it and put 220 sandpaper on a 120 worn out pad. Clogs up in 30 seconds and starts burning wood afterwards. If you have no choice, but to use an angle grinder then you really need to get a belt cleaner and change those pads often when they stop taking the handle material off easily, like a minute or two is all. Buy an inexpensive 2x42 belt sander and get the belts from Tru-Grit.com
This is the best 2x42 belt sander for the budget minded knifemaker, they make better, but the price goes way up. They make cheaper too, but they are weak for the most part. There are knifemakers who use the 2x42 and though not ideal, it's better than an angle grinder. It comes with a 6" disc too for doing flats or angles.
https://www.zoro.com/dayton-beltdisc...45/i/G2309045/
Like Ray said, get a cheap belt sander, a 1x30 from harbor freight is cheap too, but those little belts don't last long and you'll be burning handles real quick if you try to save on belts.