When you get a new brush, as in a CND Pro-Styler (excellent brush btw for L&P) it got starch in it's bristles to keep it's shape during stransit, so take off the clear plastic brush cover and THROW IT AWAY! NEVER and I repeat NEVER put it back on the brush - as it'll melt onto the brush!
Get you new brush & a dappen dish at least half full of your chosen monomer. Before dipping the new brush into the monomer, 'break' the starchy stuff out of the brush by bending it back & forth on a lint free wipe. Keep your eye on the bristles as you bend it too and fro, then dip it fully into your monomer to immerse it fully, allow all the air bubbles to come out and then clean it again on a FRESH bit of lint free wipe, keep this up until you are sure there are no more bits or stuck together bristles, change your monomer as often as you need to get your brush thoroughly clean. Then it's ready for use, after use, empty out your used monomer (wiping the dappen dish with a lint free wipe to get rid of contaminants) & put fresh monomer into your dappen dish and press your brush around in it, dispelling all the old stuff & powder etc, wipe on a lint free pad, and store in a CND brush case, or at the very least laying flat, with a lint free wipe/pad at the bristles to stop it from touching anything - do not allow it to touch your skin, even when cleaning it, or squeezing out the monomer between 2 lint free wipes.
HTH's xx