We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Thermochemical Preference for C–C Bond Scission in an Isotactic Polypropylene Oligomer: A DFT-Based Study
Original title: Thermochemical Preference for C–C Bond Scission in an Isotactic Polypropylene Oligomer: A DFT-Based Study
Summary
Scientists used computer modeling to figure out exactly where plastic (polypropylene, found in food packaging and countless products) is most likely to break down when heated, pinpointing the weakest links in its molecular chain. This matters because understanding how plastic breaks apart at a molecular level helps researchers predict how it degrades into smaller pieces, including microplastics, which is a key step toward developing better recycling methods or reducing harmful breakdown products that could affect human health.
Polypropylene (PP) waste, including microplastic debris, motivates molecular-scale studies of the intrinsic factors governing thermal degradation. In this work, the bond dissociation energies (BDEs) of C–C and C–H bonds were systematically evaluated in a finite isotactic polypropylene oligomer containing fifteen propylene repeat units, (–C3H6–)15, using Density Functional Theory at the M06-2X/LANL2DZ level. Thermochemical corrections were evaluated at 873.15 K, a temperature relevant to pyrolysis studies. Within the selected oligomer model, C–C bonds exhibited lower BDE values (82.28–87.41 kcal·mol−1) than C–H bonds (90.18–104.93 kcal·mol−1), indicating a thermochemical preference for backbone scission. The lowest calculated BDE values were associated with specific tertiary carbon environments, including sites C24 and C28. A mixed-effects model identified bond type and carbon type as the principal factors associated with BDE variation, while principal component analysis summarized the covariation among the electronic and thermodynamic descriptors. These results provide a molecular-scale description of intrinsic scission tendencies within the selected PP oligomer and establish a basis for subsequent kinetic, catalytic, and experimental studies.