Reprocessing Of Thermosetting Plastic Foam SAN Scrap To Produce Fiber-reinforced Plaques With High Performance

With development of plastic industry, cost-effective methods of recycling scrap thermosetting polymers with products of excellent mechanical properties are needed. In this article, methods for recycling themosetting styrene acrylonitrile copolymer (SAN) scrap were developed with hot-compression methods, and fibers were employed to enhance the products' properties.In this thesis, SAN waste was reprocessed employing compression moulding, and the processing conditions were tested and improved. Also, different fibers (Nylon, PVC and jute fibers) with different pre-treatments were compared to determine the effect of fiber-reinforcement. The realtionships among the properties, structures and processing conditions of the final products were investigated and fracture morphology analysis was conducted to determine the mechanisms of jute fiber reinforcement. Also, facing materials were also applied to decorate and reinforced the fiber-reinforced composite.Raw SAN waste was grinded into granules with average sizes ranging from 300 to 1000μm and was produced into plates with density of 0.9 g/cm~3. Results showed that the best processing conditions of compression moulding were as follows: heating temperature: 195℃/185℃; processing pressure: 15 MPa; processing time: 15 min. Mechanical properties analyses showed that jute fibers after pre-processing with DMAc significantly improved the impact strength (19.87±4.26 kJ/m2), flexural strength (41.686±6.471 MPa) and compressive strength (60.966±8.265 MPa) of composites. The mechanical properties of composite were slightly enhanced by kraft paper, with impact strength of 23.58±2.92 kJ/m2 , flexural strength of 42.642±5.361 MPa,and compressive strength of 61.767±10.256 MPa. According to the SEM analysis, the DMAc pre-treatment of jute fibers improved the interface properties between jute fibers and SAN matrix, and therefore improved the mechanical properties of the final products. SEM analysis showed that DMAc improve the interface properties, improve the stress transfer at the interface, and thus improve the mechanical properties of the product.