TY - JOUR
T1 - Cross-Linking of Polypropylene via the Diels-Alder Reaction
AU - Muljana, Henky
AU - Arends, Stefan
AU - Remerie, Klaas
AU - Boven, Gert
AU - Picchioni, Francesco
AU - Bose, Ranjita K
PY - 2022
Y1 - 2022
N2 - In this work, the possibility of preparing cross-linked polypropylene (PP) via Diels-Alder (DA) chemistry is explored. The overall strategy involves reaction of maleated polypropylene (the starting material), furfuryl amine (FFA), and bismaleimide (BM) as the cross-linking agent. The occurrence of reversible cross-linking was studied by checking the presence of relevant peaks in FTIR spectra, i.e., CH out-of-plane bending vibrations of the furan ring's peak (γCH) at an absorption band of 730-734 cm-1, CH=CH of the BM aromatic ring's stretching vibrations (υCH=CH) at an absorption band of 1510 cm-1, and the DA adduct (C-O-C, δDAring) at an absorption band of 1186 cm-1. In agreement with the spectroscopic characterization, the presence of a cross-linked network is also confirmed by rheology, namely the higher storage modulus (G') compared with loss modulus (G″) value (G' >> G″), as obtained via temperature sweep. Both the maleic anhydride (MA) content as well as the annealing temperature (50 °C and 120 °C) favor the DA reaction, while only partial de-cross-linking (retro DA) is observed at the higher temperature range of 150-200 °C. In addition, the products show higher mechanical robustness and thermal stability compared to the starting material.
AB - In this work, the possibility of preparing cross-linked polypropylene (PP) via Diels-Alder (DA) chemistry is explored. The overall strategy involves reaction of maleated polypropylene (the starting material), furfuryl amine (FFA), and bismaleimide (BM) as the cross-linking agent. The occurrence of reversible cross-linking was studied by checking the presence of relevant peaks in FTIR spectra, i.e., CH out-of-plane bending vibrations of the furan ring's peak (γCH) at an absorption band of 730-734 cm-1, CH=CH of the BM aromatic ring's stretching vibrations (υCH=CH) at an absorption band of 1510 cm-1, and the DA adduct (C-O-C, δDAring) at an absorption band of 1186 cm-1. In agreement with the spectroscopic characterization, the presence of a cross-linked network is also confirmed by rheology, namely the higher storage modulus (G') compared with loss modulus (G″) value (G' >> G″), as obtained via temperature sweep. Both the maleic anhydride (MA) content as well as the annealing temperature (50 °C and 120 °C) favor the DA reaction, while only partial de-cross-linking (retro DA) is observed at the higher temperature range of 150-200 °C. In addition, the products show higher mechanical robustness and thermal stability compared to the starting material.
U2 - 10.3390/polym14061176
DO - 10.3390/polym14061176
M3 - Article
C2 - 35335509
SN - 2073-4360
VL - 14
JO - Polymers
JF - Polymers
IS - 6
M1 - 1176
ER -