| Summary: | 碩士 === 東海大學 === 化學系 === 88 === Abstract
The formation of rubber particles is the most important step in HIPS production. There are many interrelated variables involved, it is difficult to describe them quantitatively. The main purpose of this paper is to simulate the conditions of HIPS prepolymerization by using polystyrene of different molecular weight, and different PB/PS ratio, and use SBS to instead of PB to observe the effect of PS molecular weight on the formation of rubber particles.
In the experiment of PS/PB/SM system, the concentration of PB was controlled between 2~9wt.%, and PS is between 2~9wt.%. It was found that the PB/SM/PS system separated into a PB/SM upper layer and a PS/SM lower layer. This separation was caused by gravity and it was not affected by temperature. The distribution of the particle size is a bimodal. In addition, the following phenomena were observed：
(1).As the polystyrene molecular weight increases：
the distribution of particle size is narrower, the amount of particle increases, the amount of increase in the larger particles (above 10µm) is lower and the total volume of particles is greater.
(2).AS the concentration of polystyrene and rubber increases：
the distribution of particle size becomes wider, the number of particle increases, the number of larger particles becomes higher and the total volume of particles increases.
(3).As the PS in the system increases：
the distribution of particle size becomes wider, the number of larger particle increases.
(4).As the SBS to replace PB increase：
the distribution of particle size is narrower, the amount of particle increases, the amount of increase in the larger particles is lower and the total volume of particles is greater.
(5).As the shear rate increases：
the distribution of particle size becomes narrower and the average diameter of particles becomes smaller.
(6).The time after separation is longer：
the distribution of particle size becomes narrower and the number of larger PB particles decreases.
|
|---|
