Natural-sourced benzoxazine resins, homopolymers, blends and composites: A review of their synthesis, manufacturing and applications

Advances in sustainable thermosetting resins: From renewable feedstock to high performance and recyclability

The general flammability of polymer materials is a crucial problem to be solved in industrial applications. Polyphosphazenes, a kind organic-inorganic polymer and whose main chain is alternating by single and double bonds of phosphorus, nitrogen are endowed with excellent natural flame retardant synergies and thermal stability. Therefore, utilizing the designability of molecular structure and excellent flame retardant performance of polyphosphazene, a series of polyphosphazene flame retardants based on linear and cyclocrosslinked structures have been synthesized to improve the comprehensive properties especially the flame retardant properties, thermal stability and mechanical properties of materials, which is reviewed here. In particular, the molecular structure design and morphological changes of polyphosphazenes, flame retardant mechanism and the performance of flame retardant materials have been systematically discussed. As an important member of environmentally friendly halogen-free flame retardants, the challenges and opportunities encountered by polyphosphazene flame retardant materials have also been proposed in this review. In view of the excellent physical and chemical properties of polyphosphazenes, it's believed that an increasingly important role would be played by polyphosphazenes not only in flame retardant application but also in other application fields such as biomedicine and environmental adsorption.

Polyphosphazenes-based flame retardants: A review

Magnolol-based bio-epoxy resin with acceptable glass transition temperature, processability and flame retardancy

Sustainable polymers from lignocellulosic biomass have the potential to reduce the environmental impact of commercial plastics while also offering significant performance and cost benefits relative...

100th Anniversary of Macromolecular Science Viewpoint: Polymers from Lignocellulosic Biomass. Current Challenges and Future Opportunities

We report on the preparation of hexa-functional cardanol (renewable phenolic compound) benzoxazine with a phosphazene core (CPN) for use as a greener eco-friendly halogen-free flame retardant reactive additive for the formation of sustainable polyphosphazene polybenzoxazine networks for flame resistant applications. The structure and purity of the monomer was confirmed by Fourier transform infrared (FTIR), nuclear magnetic resonance (1H-, 13C-, 31P NMR) and gel permeation chromatography studies. The CPN monomer showed good compatibility with benzoxazine monomer (CPN0) as suggested by the cocuring studies. The thermal properties of the copolymer can be directly tuned by altering the composition of the monomer blend. The occurrence of phosphazene–phosphazane thermal rearrangement is also suggested for the thermal behavior (thermogravimetry analysis) at higher loading of CPN in the monomer feed ratio. An improvement in mechanical properties of the copolymer with increase in glass transition temperature was c...

Eco-friendly halogen-free flame retardant cardanol polyphosphazene polybenzoxazine networks

Isomerization of double bonds from an allylic to propenyl position is generally mediated by expensive metal catalysts, demanding an additional synthetic step, thereby reducing sustainability of the...

Harvesting the Benefits of Inherent Reactive Functionalities in Fully Biosourced Isomeric Benzoxazines

Due to their outstanding and versatile properties, polybenzoxazines have quickly occupied a great niche of applications. Developing the ability to polymerize benzoxazine resin at lower temperatures than the current capability is essential in taking advantage of these exceptional properties and remains to be most challenging subject in the field. The current review is classified into several parts to achieve this goal. In this review, fundamentals on the synthesis and evolution of structure, which led to classification of PBz in different generations, are discussed. Classifications of PBzs are defined depending on building block as well as how structure is evolved and property obtained. Progress on the utility of biobased feedstocks from various bio-/waste-mass is also discussed and compared, wherever possible. The second part of review discusses the probable polymerization mechanism proposed for the ring-opening reactions. This is complementary to the third section, where the effect of catalysts/initiators has on triggering polymerization at low temperature is discussed extensively. The role of additional functionalities in influencing the temperature of polymerization is also discussed. There has been a shift in paradigm beyond the lowering of ring-opening polymerization (ROP) temperature and other areas of interest, such as adaptation of molecular functionality with simultaneous improvement of properties.

Review on the Accelerated and Low-Temperature Polymerization of Benzoxazine Resins: Addition Polymerizable Sustainable Polymers.

Biobased phenols and amines are attractive feedstock in rapid emerging polybenzoxazine thermosets. Renewable benzoxazines are mainly monofunctional due to structure limitation of raw materials, esp...

Isomannide-Derived Chiral Rigid Fully Biobased Polybenzoxazines

https://onlinelibrary.wiley.com/doi/pdf/10.1002/macp.201970005

Nagarjuna Amarnath

Papers

Eco-friendly halogen-free flame retardant cardanol polyphosphazene polybenzoxazine networks

Harvesting the Benefits of Inherent Reactive Functionalities in Fully Biosourced Isomeric Benzoxazines

Review on the Accelerated and Low-Temperature Polymerization of Benzoxazine Resins: Addition Polymerizable Sustainable Polymers.

Isomannide-Derived Chiral Rigid Fully Biobased Polybenzoxazines

Cardanol Benzoxazines: A Versatile Monomer with Advancing Applications