Why is the POE grafting maleic anhydride grafting rate controlled at 0.6-1.0?
Then here and you sort out, nylon toughening, it in the end there are two requirements, one is only the pursuit of normal temperature toughening, and the low-temperature cold resistance requirements are not high, the other is focused on the pursuit of low-temperature cold resistance effect.
Normal temperature toughening
When only room temperature toughening is sought, a lower grafting rate and a higher crosslinking degree are more powerful.
This is because only in this case will it be dispersed in the nylon to form a larger particle size, but not a larger number of morphological structures, thus better absorbing the impact energy during the impact at room temperature and providing a better toughening effect.
Some partners in the production found with a part of the non-grafted POE plus a part of the grafted POE, two intermix to use, do out of the room temperature toughening data is very high instead.
Therefore, we should not pursue too high a grafting rate for room temperature toughening, around 0.3 is more appropriate.
Low temperature toughening
In the case of low-temperature toughening, it is of course necessary to pursue a good grafting rate and a low cross-linking degree.
Why is this so? When the grafting rate is high and the cross-linking degree is low, it can form a finer but more numerous tiny elastomer particles, which are dispersed in the nylon, and in the process of temperature drop, it will produce shrinkage and deformation.
Therefore, if we pursue low-temperature toughening, we must not intermix POE without grafting as we do for normal-temperature toughening, but must pursue high grafting rates.
For COACE, our POE grafting is usually done in the range of 0.6-1.0, which is the best value to take into account the demand for normal temperature and low temperature toughening.