Plastics Processing, 1. Processing of Thermoplastics

Scalable synthesis of methacrylate-based vitrimer powders by suspension polymerization

“…1 Thermoplastics are non-crosslinked polymers that can be processed with relative ease but have poor mechanical resistance. 2 In contrast, thermosets have a chemically crosslinked network structure and cannot be reshaped or reprocessed once synthesized, but have better mechanical properties and chemical resistance. 3 Recently, new approaches have sought to combine the processability of thermoplastics with the mechanical properties of thermosets through the use of dynamic bonds to yield so-called covalent adaptable networks (CANs).…”

Elucidating pathways of polypropylene chain cleavage and stabilization for multiple loop mechanical recycling

“…PP is produced globally at annual volumes exceeding 75 million tons and is used in a wide variety of applications 5 : in packaging (e.g., lids and caps), automotive applications (e.g., bumpers, battery housings), building and construction (e.g., pipes), agriculture (tanks or storage bags) or household appliances. As a thermoplastic polymer it can be employed as filled 15 or unfilled material and processed by a variety of technologies, 16 including injection molding, blow‐molding, or fiber spinning. In addition to being one of the mainstay polyolefins, and one with the broadest set of applications, PP has additional benefits for mechanistic studies of degradation in multiple recycling: PP degradation follows a clear path (Figure 2) that occurs practically exclusively by chain scission 17 in contrast to, for example, low density polyethylene, in which radical attack on the chain also leads to chain branching 18 …”