Fullerene C₆₀ Derivatives as High-Temperature Inhibitors of Oxidative Degradation of Saturated Hydrocarbons

Abstract

Exsperimental details S13 Scheme S1. Schematic diagram for the synthesis of C60-Py S4 Scheme S2. Schematic diagram for the synthesis of C60-I S4 Scheme S3. Schematic diagram for the synthesis of C60-II S6 Scheme S4. Schematic diagram for the synthesis of C60-III S8 Scheme S5. Schematic diagram for the synthesis of C60-IV S11

Fullerene C60 conjugated with phenols as new hybrid antioxidants to improve the oxidative stability of polymers at elevated temperatures

“…Synthesis and characterization of C 60 derivatives is described in ref. 22, and quoted in ESI. † T e collected for series of different b's (see, for example, Fig.…”

“…above T iso the process with higher E a proceeds faster). 22,24 For example, oxidation of polyethylene inhibited by 1% C 60 -III is described by E a ¼ 120 kJ mol À1 and Z ¼ 1.2 Â 10 12 min À1 , giving the rate constants 1.85 Â 10 À5 min À1 at 100 C and 0.066 min À1 at 200 C. If 1% C 60 -IV is used, the kinetic parameters E a ¼ 148 kJ mol À1 and Z ¼ 3.7 Â 10 15 min À1 allow to calculate k 100 C ¼ 8.38 Â 10 À6 min À1 and k 200 C ¼ 0.193 min À1 . Thus, at 100 C C 60 -IV is more active than C 60 -III whereas at 200 C the derivative C 60 -III is more active than C 60 -IV.…”

“…Depending on the k p for propagation of lipid or hydrocarbon, the same molecule can behave as a good antioxidant in hydrocarbon (k inh /k p > 1000) but with no antioxidant activity (no induction period will be observed) in unsaturated hydrocarbon (k inh /k p ( 1000). 22 Additional explanation of good antioxidant behaviour of the studied conjugates of C 60 with phenols is that we monitored a real process of oxidation carried out at temperature above 150 C where some other radical species can effectively mediate the kinetic chain process of propagation step during hydrocarbon autoxidation. We assign this inhibitory effect as a result of low volatility of C 60 conjugates, ability of phenolic moieties to react with peroxyl radicals and ability of fullerene spheres to react with other radicals like alkoxyl, alkyl, hydroxyl radicals as well as singlet oxygen formed during high temperature decomposition of peroxides (including non-Russel type reaction of tetraoxides).…”

“…21 For high temperature oxidation of STA, the phenolic conjugates of C 60 are more active antioxidants than the pristine C 60 and phenols used alone. 22 This lead us to hypothesis that conjugates of C 60 with phenols are good candidates for hybrid antioxidants to be used in polymers at temperatures above 100 C. Herein we present experimental study in which kinetic parameters of thermo-oxidation of pure high density polyethylene (HDPE) were determined and compared with kinetic parameters of HDPE containing pristine fullerene C 60 and C 60 adducts with four phenols I-IV (see Chart 1) at concentration 0.065-1%.…”

Fabrication of fullerene decorated by iron compound and its effect on the thermal stability and flammability for high‐density polyethylene

“…It is well known that C 60 has high efficiency in capturing free radicals, named as a radical sponge . The free radical reactions between C 60 and other compounds have been investigated . Martinez G et al proved that the incorporation of C 60 in isotactic polypropylene ( i ‐PP) induced a free‐radical reaction between C 60 and i ‐PP, which enhanced the thermal stability of i ‐PP significantly.…”