Waste polystyrene foams for the preparation of non-toxic adhesives

1 Introduction

Styrofoam is widely used as shock-proof packaging materials and convenience food containers for instruments and meters, handicrafts, and household appliances because of its light weight, non-toxicity, and easy molding. It is used as a decoration, decoration, and insulation material in the construction industry; in the machinery industry. It is also used to make gasification molds for solid casting. However, when used in the above applications, they are often used once, or a large amount of scrap is generated during the forming process. This will not only cause serious environmental pollution, but also cause a lot of waste. Therefore, it is reasonable and effective. Exploitation of waste foam is an important research topic.

At present, of the research reports on the recycling of polystyrene foam, some use the melt extrusion method to regenerate the polystyrene foam raw material, but the energy consumption is large, and the recycled foam is inconvenient to do the defoaming and volume reduction treatment on the spot. High transportation costs; some use thermal cracking process to obtain styrene monomer, oil and bitumen, but the process is complicated, large equipment investment is inconvenient to promote the application [1]; some directly broken granulation, adding new particles to reuse, However, this method has low utilization efficiency and generates a large number of droplets in the crushing process, which is unfavorable to the health of the workers; it also uses solvents to modify and prepare adhesives [2～3], but most of them use toxic solvents (such as toluene, halogenated hydrocarbons, etc.) or Due to high solvent prices (such as esters), they have not been put into practical use. The purpose of this study is to use a non-toxic or low-toxic, inexpensive solvent to defoam the foam and reduce the volume of the foam, and then use a simple process to produce a high value-added adhesive product, so that the formula is simple, the process is stable and reliable, and the product is non-toxic. Produce secondary pollution, easy to promote the application.

2 Experimental studies

2.1 Raw materials

Waste polystyrene foam, organic solvents, industrial oils, zinc oxide (filler), dibutyl phthalate. In addition to the requirements for the selection of organic solvents, such as non-toxic or low-toxicity, readily available raw materials, and low prices, the composition and structure of polystyrene should also be fully considered. Because polystyrene is a non-polar polymer compound, the selected organic solvent should also be non-polar. Only in this way can the polystyrene foam be fully infiltrated, thereby achieving the purpose of defoaming and volume reduction and dissolving it for the next step. Offer possible.

2.2 Process (see Figure 1)

During the experiment, the waste polystyrene foam is slightly purified, and the selected organic solvent is used for defoaming and volume reduction. After recovery is concentrated, the base rubber is prepared using industrial oil, and the toughness of the obtained rubber is poor. Low strength, large shrinkage during curing, therefore, the final addition of dibutyl phthalate to improve its toughness, but also can adjust the curing time to meet the needs of the construction; also added zinc oxide (particle size ≤ 200 mesh ) As a filler to reduce the shrinkage during curing.

2.3 Formulation and the role of various components

2.3.1 Basic rubber formula (Table 1)

2.3.2 Adhesive formulations (Table 2)

2.4 Properties of Adhesives The properties of adhesives produced using the above processes and formulations are shown in Table 3:

3 Conclusion

1) Use low-toxicity, cheap organic solvents and industrial oils in combination with a certain process to recover waste polystyrene foam into adhesives. The process is stable and simple. The resulting wood-to-wood compressive shear strength of the adhesive is 2.2 MPa. Bonding wood floors, tiles, paper, etc.

2) The research method was searched by the Information Retrieval Center of the Institute of Scientific and Technical Information of Hubei Province and the conclusion was: “After searching, there is no report on the same literature that has been used to recover polystyrene foam in the commissioned project.”

3) The recycling of waste foam plastic can not only eliminate the environmental pollution caused by it, but also has good economic benefits and social benefits because it is old and waste, low cost, simple process, stable and reliable, no secondary pollution. Benefits are worth promoting and applying.

Source: 21st Century Fine Chemicals Network