Synthesis, curing process and thermal reversible mechanism of UV curable polyurethane based on Diels-Alder structure

Ke, Xiao-Xue; Liang, Hongbo; Xiong, Lei; Huang, Shengmei; Zhu, Min

doi:10.1016/j.porgcoat.2016.03.008

Cited by 23 publications

(31 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The residual weight percent of this UV‐cured MAPSO is much higher than those of previous researches, and is similar to those of the UV‐cured silicone rubber which was prepared via thiol‐ene click reaction by using high‐molecular‐weight polydimethylsiloxane containing vinyl groups . In addition, the residual weight percent is also higher than UV curable polyurethane in which residual weight percent is only 3.5% at 600 °C …”

Section: Resultssupporting

confidence: 72%

Effect of Polymerizable Photoinitiators on the UV‐polymerization behaviors of photosensitive polysiloxane

Jiang

Zhang

Zhao

et al. 2017

J. Polym. Sci. Part A: Polym. Chem.

View full text Add to dashboard Cite

In this contribution, three polymerizable benzophenone photoinitiators containing maleimide group including 4‐maleimidebenzophenone (MBP), 4‐chlorine‐4′‐maleimide benzophenone (CMBP), and 4‐maleimide‐4′‐[(4‐maleimide)thiophenyl]benzophenone (MMTBP) were designed and synthesized to enhance the polymerization degree of photosensitive polysiloxane containing methacryloxy active groups (MAPSO). The polymerization behaviors of the MAPSO cured by different photoinitiators were investigated using Fourier transform infrared (FTIR). It was noted that the MAPSO initiated by MMTBP showed a high carbon–carbon double bond conversion above 80% because of the existence of thiophenyl group which could generate more radicals from the photolysis reaction at the CS bond. In addition, the thermal stability of the UV‐cured MAPSO were studied by thermogravimetric analysis (TGA), the result showed that the initial 5% mass loss (T5%) and residual weight percent at 800 °C in nitrogen of the UV‐cured MAPSO initiated by MMTBP systems was 200 °C and 33.8%. Thus, this work provides a new perspective and efficient strategy to improve the polymerization degree of UV‐curable polysiloxanes with carbon–carbon double bonds. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 1696–1705

show abstract

Section: Resultssupporting

confidence: 72%

Effect of Polymerizable Photoinitiators on the UV‐polymerization behaviors of photosensitive polysiloxane

Jiang

Zhang

Zhao

et al. 2017

J. Polym. Sci. Part A: Polym. Chem.

View full text Add to dashboard Cite

show abstract

“…After the additional thermal treatment, the appearance of a distinct maleimide band at 697 cm −1 indicated opening of Diels–Alder groups by a retro Diels–Alder reaction. [ 49 ]…”

Section: Resultsmentioning

confidence: 99%

Thermally Reversible Diels–Alder Bond‐Containing Acrylate Networks Showing Improved Lifetime

Maassen

Anastasio

Breemen

et al. 2020

Macro Chemistry & Physics

View full text Add to dashboard Cite

printing). [5] A key requirement for all these applications is spatiotemporal control of the polymerization reaction. [6] Commonly used monomers for photopolymerization are (meth)acrylates, which polymerize quickly, [7,8] and form a polymeric network with high dimensional stability and good resistance to heat and solvents. However, polymerization of multifunctional (meth)acrylates into a highly crosslinked network is often accompanied by stress development due to volumetric shrinkage, [9-11] which is the largest shortcoming in bulk applications such as stereolithography. [12] In the liquid monomer resin, the molecules interact weakly through van der Waals forces which define the intermolecular distance. [13] During the polymerization, covalent bonds are formed, which are shorter than the van der Waals distances between monomers in the initial mixture. The density will increase and volumetric shrinkage will occur; [7,12] the conversion of CC to CC bonds results in a volumetric shrinkage of 23 cm 3 mol −1. [14] Furthermore, energy dissipation through material flow is inhibited by cross-links, causing stress build-up in the material. [15,16] The shrinkage-induced stress can cause creep distortions or crack formation, leading to premature material failure. [17] Several methods toward reducing the volumetric shrinkage in (meth)acrylic systems have been investigated, e.g., the use of composite materials, [18-20] adjusting the bulkiness of the monomers, [21-23] the use of a volumetric expansion, [24-26] and covalent adaptable networks (CANs). [27-30] In CANs, rearrangement of a dynamic network is triggered by a specific stimulus, [27] where the chemistry of dynamic bonds determines the nature of the stimulus. [31,32] Bowman and co-workers developed photochemically controlled reversible addition-fragmentation monomers which show efficient stress relaxation when incorporated in (meth)acrylate networks. [30,33,34] Inspired by the studies on CANs, here we explore the use of reversible bond formation to counteract the results of volumetric shrinkage. A well-known example of thermally reversible covalent bond formation is the Diels-Alder reaction. While reversible Diels-Alder reactions have been used to create self-healing materials [35-37] and recyclable thermosets, [38,39] they have, to the best of our knowledge, not been explored for the current purpose. Since reversible Diels-Alder reactions have a low activation energy, these reactions can be used in the photopolymerization of (meth)acrylates without adding a catalyst; the Diels-Alder and retro Diels-Alder Photopolymerization of (meth)acrylates into highly crosslinked networks is in general accompanied by volumetric shrinkage, often leading to premature material failure. In this work, thermoreversible Diels-Alder groups are investigated to explore their effect on material lifetime. A difunctional acrylic monomer containing Diels-Alder moieties is synthesized and successfully incorporated in a polymer network by photopolymerization. It is demonstrated that upon heating ...

show abstract

“…This may be because the thickness of the prepared coating was much lower than that of the coating lm, which reduced the interactions among the molecular chains and thus affected the self-healing efficiency of the coating. In another study, Ke et al 35 synthesized polyurethane acrylates by using diols containing D-A bond as chain extender and prepared UV-curable coating containing D-A covalent bond through free radical polymerization induced by photoinitiator. The coating exhibited a strong self-healing ability at 120 °C; however, the high temperature required for the coating to selfheal limited its practical application.…”

Section: D-a Reactionsmentioning

confidence: 99%

Research advances in UV-curable self-healing coatings

Guo

2022

RSC Adv.

View full text Add to dashboard Cite

show abstract

Synthesis, curing process and thermal reversible mechanism of UV curable polyurethane based on Diels-Alder structure

Cited by 23 publications

References 24 publications

Effect of Polymerizable Photoinitiators on the UV‐polymerization behaviors of photosensitive polysiloxane

Effect of Polymerizable Photoinitiators on the UV‐polymerization behaviors of photosensitive polysiloxane

Thermally Reversible Diels–Alder Bond‐Containing Acrylate Networks Showing Improved Lifetime

Research advances in UV-curable self-healing coatings

Contact Info

Product

Resources

About