Strengthening and toughening of polybenzoxazine by incorporation of polyrotaxane molecules

Chen

et al. 2023

ACS Appl. Eng. Mater.

Self Cite

The inherent brittleness of polybenzoxazines (PBas) makes them difficult for high-performance microelectronics and composite applications. Conventional toughening approaches are either ineffective or cause a reduction in the glass transition temperature (T g ) of PBa. Polyrotaxane (PR), a mechanically interlocked supramolecular polymer, is an effective toughening agent to improve the tensile strength and fracture toughness of various polymers due to its unique topological structure. In this study, the effect of the molecular weight and functional groups of PRs on the morphology and mechanical properties of PR-modified PBa was investigated. PBa toughened by well-dispersed epoxide-functionalized PR (EPR) and benzoxazine-functionalized core−shell rubber (BCSR) was found to greatly enhance fracture toughness without compromising Young's modulus or T g . The fracture toughness is significantly improved from 0.82 MPa m 1/2 for neat PBa to 1.49 MPa m 1/2 for PBa/EPR/BCSR. The synergistic toughening effect is explained by the molecularly dispersed EPR in the PBa network, which results in higher network chain mobility, which promotes more cavitation of BCSR and triggers larger matrix plastic deformation. It is believed that the knowledge gained from the present study can help develop tougher polymers for vast engineering applications, especially in electronics, automotive, and aerospace applications.

Section: Resultsmentioning

confidence: 99%

Section: Mechanical Behaviors Of the Pba/pr/bcsr Systemsmentioning

confidence: 99%

Section: Mechanical Behaviors Of the Pba/pr/bcsr Systemsmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Fracture Behavior of Polybenzoxazine Toughened by Polyrotaxane Molecules and Core–Shell Rubber

Chen

et al. 2023

ACS Appl. Eng. Mater.

Self Cite

J of Applied Polymer Sci

Design, Synthesis, and Evaluation of Benzoxazine Copolymers for Anti‐Corrosion Coating Applications Based on Improved High Crosslinking Density and Hydrophobicity

Zhang,

Zhao,

et al. 2024

The main‐chain benzoxazine (BA‐ddm) and diamine‐type benzoxazine (Ph‐hda) were prepared by solution method, and a series of copolymers were prepared by mixing them at various mass ratios. Second, copolymer coatings (P(PB)) were prepared on the surface of the tinplate by dip coating and heat curing. The results of FTIR and 1HNMR showed that the benzoxazine copolymer coating was successfully prepared. DSC test results showed that the copolymerization of two benzoxazine oligomers was promoted by the introduction of BA‐ddm containing phenolic hydroxyl groups. The introduction of Ph‐hda containing a long aliphatic chain provided the copolymer coatings with good hydrophobicity, as verified by the hydrophilicity and hydrophobicity tests. When the mass ratio of BA‐ddm to Ph‐hda was 1:19, the water contact angle and water absorption of P(PB5) were 100.10% and 0.56%, respectively. The results of dynamic polarization curves and electrochemical impedance spectroscopy (EIS) indicated that different copolymer coatings had good corrosion resistance. Among them, the P(PB5) coating exhibited the best anti‐corrosion performance, with a corrosion current of 5.15 × 10−8 A cm−2, a protection efficiency of 99.23%, and an impedance modulus of 1.78 × 107 Ω cm2 at 0.01 Hz, which was nearly 5 orders of magnitude higher than the impedance modulus of the blank tinplate.

Polyrotaxane‐Based Functional Materials Enabled by Molecular Mobility and Conformational Transition^†

Cui

Zhang

2023

Chin. J. Chem.

Comprehensive SummarySlide‐ring structured polyrotaxanes with high molecular mobility and reversible conformational transition ability can achieve high performance and multifunctionality of the material in various applications. There have been many reviews describing advances in the research of rotaxanes and polyrotaxanes. However, most of them typically focus on the precise synthesis of mechanically interlocked molecules and the control of microscopic molecular shuttles. In this review, we examine the effects of motion activity and conformational transition due to molecular slide on the performance of polyrotaxanes and the latest functional applications. Different designs of polyrotaxane‐based functional materials are presented to improve the potential for applications including self‐healing stretchable elastomers/gels, stimuli‐responsive smart devices, battery electrode binders, and biomedical drug delivery. It is anticipated that this review will provide insights and guidance for future developments in the design, synthesis and application of polyrotaxane‐based functional materials.