Catalyzing the Ring-Opening Polymerization of 1,3-Benzoxazines via Thioamide from Renewable Sources

Coban, Zehra Gul; Yaǧcı, Yusuf; Kışkan, Barış

doi:10.1021/acsapm.1c00637

Cited by 14 publications

(14 citation statements)

References 70 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because strong inter- and intramolecular hydrogen bonds exist after the thermal ROP of BZ units, formed among the tertiary amino and phenolic units in the Mannich bridges, the polymerization products can possess low dielectric constants, low surface free energies, low degrees of shrinkage, and high thermal stabilities and char yields [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. Flexibility in molecular design—by varying the structures of the phenolic and amino groups—has allowed the introduction of a range of functional groups (e.g., allyl, propargyl, crown ether) [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ] or inorganic nanomaterials (such as polyhedral oligomeric silsesquioxane, graphene, carbon nanotube) [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ] into the BZ matrix.…”

Section: Introductionmentioning

confidence: 99%

Metal Complexes of the Porphyrin-Functionalized Polybenzoxazine

et al. 2022

View full text Add to dashboard Cite

New porphyrin-functionalized benzoxazine (Por-BZ) in high purity and yield was synthesized in this study based on 1H and 13C NMR and FTIR spectroscopic analyses through the reduction of Schiff base formed from tetrakis(4-aminophenyl)porphyrin (TAPP) and salicylaldehyde and the subsequent reaction with CH2O. Thermal properties of the product formed through ring-opening polymerization (ROP) of Por-BZ were measured using DSC, TGA and FTIR spectroscopy. Because of the rigid structure of the porphyrin moiety appended to the benzoxazine unit, the temperature required for ROP (314 °C) was higher than the typical Pa-type benzoxazine monomer (ca. 260 °C); furthermore, poly(Por-BZ) possessed a high thermal decomposition temperature (Td10 = 478 °C) and char yield (66 wt%) after thermal polymerization at 240 °C. An investigation of the thermal and luminescence properties of metal–porphyrin complexes revealed that the insertion of Ni and Zn ions decreased the thermal ROP temperatures of the Por-BZ/Ni and Por-BZ/Zn complexes significantly, to 241 and 231 °C, respectively. The metal ions acted as the effective promoter and catalyst for the thermal polymerization of the Por-BZ monomer, and also improved the thermal stabilities after thermal polymerization.

show abstract

Section: Introductionmentioning

confidence: 99%

Metal Complexes of the Porphyrin-Functionalized Polybenzoxazine

et al. 2022

View full text Add to dashboard Cite

show abstract

“…Additionally, the demand for relatively high temperatures (> 200 °C) , for ring-opening polymerization (ROP) is currently among few of the major concerns. Alternatively, the polymerization of benzoxazine monomers at low temperatures is generally catalyzed by external aids. − The development of bio-origin low-temperature polymerizable benzoxazine-based FR adhesives using a sustainable approach is currently limited.…”

Section: Introductionmentioning

confidence: 99%

Greening Biobased Polybenzoxazine Network: Three Benefits in One Go

Duhan

Amarnath

Yadav

et al. 2023

ACS Appl. Polym. Mater.

View full text Add to dashboard Cite

Eco-friendly initiators and environmentally safe flame-retardant (FR) adhesives are highly desired to empower sustainability in polymers. However, incorporating all of the properties simultaneously in a single step is challenging to achieve high-performance biomass sourced polymers. Herein, biobased benzoxazine monomers sourced from agro-waste phenol (cardanol, C) were synthesized using a facile solventless catalyst-free approach. Owing to their requirement of high ROP temperature (∼ 250 °C), prolonged polymerization cycle, issues of high flammability, and poor adhesive strength of the resultant polybenzoxazines limit their applications. To alleviate these issues, blends of naturally occurring phytic acid (PA) with the monomers resulted in fast polymerization kinetics (∼90% monomer conversion in 1 h) with the formation of hybrid polybenzoxazine networks at a mild temperature (∼100 °C). PA enacted as a green initiator and reactive halogen-free biobased FR and revealed favorable interactions across the polymer framework. Benefitting from the design, physical, ionic, and covalent cross-linking network of polymers with PA accounted for the extra-strong adhesive strength (71.1 kg/cm 2 , nearly 3.7 times higher than that of the pristine polybenzoxazine). Upon burning, the hybrid polybenzoxazines exhibited extremely low flammability, superior smoke suppression and formed intumescent char as supported by the limiting oxygen index, vertical burning, and cone calorimetry measurements. The present study indicated that the benign by design approach is a way forward to green thermosets offering excellent combination properties and potential applications in the future.

show abstract

“…There have been several attempts to overcome these shortcomings and to reduce the curing temperature of Bzs. These attempts have generally involved two main strategies; designing new Bz monomers having various functionalities/moieties − and admixing different catalysts into the formulations. − Catalyst impregnation/inclusion is a facile, convenient, and efficient approach to shift the ROP exotherm to relatively low temperatures.…”

Section: Introductionmentioning

confidence: 99%

Kinetic Modeling of Ring-Opening Polymerization of Benzoxazines Using MIL-53-Al as a Potent Catalyst

Omrani

Deliballi

Kışkan

et al. 2023

Ind. Eng. Chem. Res.

Self Cite

View full text Add to dashboard Cite

In this study, we report the successful synthesis of a novel Al-based MOF/polybenzoxazine nanocomposite by a facile and green approach via thermally induced ring-opening polymerization (ROP). Structural and thermal characterization of the synthesized nanocomposite was accomplished using FTIR, XRD, BET and TGA, and DSC techniques, respectively. The Al-MOF showed catalytic activity in ROP and good thermal stability compared to the non-catalyzed system. The catalytic impact of MIL-53-Al on the ROP of benzoxazine is revealed by calorimetry at both isothermal and dynamic modes in detail. The Starink isoconversional analysis revealed that the MOF-catalyzed ROP proceeded faster at the reaction’s early stages, typically at α ≤ 40%. The Friedman method was also applied to the experimental data to get more insights into the mechanisms of the ROP reaction. Results indicated that both systems follow a conversion-dependent mechanism for cationic ROP of the benzoxazine. Although the complexity of the ROP of benzoxazines reduces the reliability of model fitting, the activation energy data were confirmed. Moreover, it was demonstrated that the reaction mechanism changes from the autocatalytic to the n-order regime during the reaction. An ROP mechanism is proposed at which the available AlO4(OH)2 octahedra act as active sites shifting the curing exotherms to lower temperatures.

show abstract

Catalyzing the Ring-Opening Polymerization of 1,3-Benzoxazines via Thioamide from Renewable Sources

Cited by 14 publications

References 70 publications

Metal Complexes of the Porphyrin-Functionalized Polybenzoxazine

Metal Complexes of the Porphyrin-Functionalized Polybenzoxazine

Greening Biobased Polybenzoxazine Network: Three Benefits in One Go

Kinetic Modeling of Ring-Opening Polymerization of Benzoxazines Using MIL-53-Al as a Potent Catalyst

Contact Info

Product

Resources

About