There are around 100,000 tons of PET bottles consumed every year in Taiwan. Green shirt made of recycled PET in Taiwan is a world-renowned products. However, the other green product made of recycled PET (rPET) is not so popular in the market as compared with recycled PP or PE product. Due to PET's rigid and tough engineering plastic property, PET is very suitable for high-valued sandwich -structured rigid foam core material. The rPET is not easy to manufacture high-valued foam core materials, because of low molecular weight of rPET, the high concentration of terminal functional groups -COOH and -OH in the molecular structure, and the poor physical properties of rPET are not easy to produce high-priced foam core materials. This project would develop extrusion foaming grade rPET formula with long-chain branch structure to meet the functional requirements of the extrusion foaming process through the combination of linear chain extension and chain branching reaction based on the molecular design concept. The rPET green foam core material could be applied to various areas of application: green high-energy-saving building, aerospace, wind energy turbines, lightweight new energy vehicles and other related high value-added markets. This project would build a mass production platform for rPET high-valued sandwich-structure foam composite in three years. In the first year, we has established rPET green foam core material via the combination of linear chain extension and chain branching reaction technology. We also has completed 10cmX1cm and 5cmX0.3cm fire-resistant rPET foam core material in the second year. This year, thanks to the results of the previous years, we will focus on market application and economic feasibility evaluation of 2 rPET fire-resistant foam core products. This project uses combination of chain extenders and flame retardant modification technology to prepare three products: flame-retardant foaming grade rPET, 3cmx3cm rPET foam lumber, 30cmX25cmX2.5cm rPET foam board and sandwich-structure composite with the rPET green foam core material (stainless steel/rPET foam/stainless steel, carbon fiber/rPET foam/carbon fiber). We have developed flame-retardant foaming grade rPET formulation, rPET with 0.6% CE chain extender and 3% flame retardant, and 3 sets of 30cmX25cmX2.5cm rPET foam board products: FEU-150 (specific gravity about 0.142~0.158), FEU-200 (specific gravity about 0.188~0.201) and FEU-250 (specific gravity about 0.225~0.233). Also we have planned 2 mass production feasibility assessments: rPET foam core extrusion line with an annual output of 4000T and rPET foam profile extrusion line with an annual output of 300T.

Polyethylene terephthalate, reactive extrusion foaming, fire retardant foam cores