| The polystyrene foam plastics (EPS) are now one of most widespread plastics applied and fast growing in the world. But, the polystyrene foam is not rotten, not degrades under the natural condition, and does create the serious environment problem. Certainly, it also has wasted the massive resources and the energy. Therefore, from on last century 80's, the processing and the recycling question of EPS have been attached to importance domestically and abroad, and massive researches have been carried. To today, the EPS recycling use still mainly manifested in: 1. Make the new light quality building materials;2. Paralyzed for getting the monomer styrene or the oil product;3. Make the modified plastic alloy by physical altogether mixture;4. Make the coating and the adhesive and so on. Each recycle mode has its merit and the deficiency, thus it is of low energy consumption, simple process, slight invest and quick return and so on, by using wasted polystyrene to produce the adhesive and the coating. Therefore this recycle way developed quickly in recent years, some achievements already were applied in the industry and obtained the good economic efficiency. But, the traditional method makes the product performance, like the adhesive viscosity, the shearing strength and so on are not very good, which has limited its application scope. According to the above, we proposed one kind of new thought -EPS is degraded first to the low-molecular polymer, then is carried on the modification by the stem grafting response again, finally the product is made into the adhesive.This experiment mainly divides into two parts, one is PS degradation, and another is the adhesive preparation. We use the benzoyl peroxide and the Y zeolite separately to carry on the oxidative degradation, catalytic and oxidative degradation respectively in the solution to PS. And the result demonstrates, under this experimental condition, the oxidative degradation and the catalytic and oxidative degradation both have the good degradation effect. But the oxidative degradation caused by BPO surpasses the catalytic and oxidatvie degeneration caused by the zeolite and BPO. Regarding the oxidative degradation, when the thermal degradation temperature is 80 ℃, the reaction time is the 2.0h;we get good effect. Becauseheating too much can cause the back reaction to happen. The BPO amount used is wt.3% and the adding way is to: ti.o= 1: 2 can take good effect. Under the above condition, the degradation scope reaches 60%.Regarding the catalytic and oxidative degradation, by the cross experiment we determined the best condition: the temperature is 85°C,the zeolite dosage is wt.5%,the BPO dosage is wt.3%,the adding way of BPO is to: ti.0=l: 2 and the reaction time are 2.0hr.After the degeneration we take the methylacrylic acid (MAA) as the modified monomer, BPO as the initiator, then carries on the emulsified response by the compound emulsifier, so as to inspect the influence of the reaction condition on the stem grafting rate and the stem grafting efficiency. The result indicated that, when the BPO amount used is wt. 1.0%, the monomer amount used is wt.8.0%, the reaction temperature is 80 ~ 90°C, the reaction time is about 3 hours, the stem grafting effect is best. Then in this foundation, we added the ingredient, like the viscosity-increasing agent phenolics (PF), the thickening-agent polyvinyl alcohol (PVC), padding ZnO and the defoamer and so on, to prepare adhesive, and discussed each kind of ingredient most suitable amount used. The result indicated that, PS degeneration degree bigger, stem grafting rate and stem grafting efficiency better, performance and so on outward appearance, viscosity and shearing strength is better, namely also confirms the original intention which we tests. |
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