Thermally Curable Acetylene-Containing Main-Chain Benzoxazine Polymers via Sonogashira Coupling Reaction

Demir, Kübra; Kışkan, Barış; Yaǧcı, Yusuf

doi:10.1021/ma1029746

Cited by 129 publications

(34 citation statements)

References 46 publications

(81 reference statements)

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“…Many different reactions such as hydrosilylation 25 , coupling 26–28 , Diels-Alder 29, 30 , Huisgen 31, 32 , Mannich 33–39 , esterification 40 , and addition 41–44 etc . were successfully applied to obtain curable polymers bearing benzoxazines with designed properties.…”

Section: Introductionmentioning

confidence: 99%

Recycling and Self-Healing of Polybenzoxazines with Dynamic Sulfide Linkages

Arslan

Kışkan

Yaǧcı

2017

Sci Rep

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In this work, a recycling and self-healing strategy for polybenzoxazines through both S-S bond cleavage-reformation reaction and supramolecular attractions is described. Both recyclable and selfhealable polybenzoxazines can be prepared from low cost chemicals with a simple procedure in only 30 minutes. For this purpose, inverse vulcanization of poly(propylene oxide)benzoxazine (PPOB) and diallybenzoxazine (B-al) with elemental sulfur was performed at 185 °C. The obtained cross-linked polymer films exhibited thermally driven recycling ability up to 5 cycles. Moreover, the self-healing ability of a test specimen was shown. Spectral characterizations, thermal stability and fracture toughness of the films were investigated after each recycling.In the past few decades, polybenzoxazines (PBZs), also known as benzoxazine resins, emerged as a superior alternative to classical resol and novolac type phenolic resins. The main structural difference of PBZs from classical phenolics is the tertiary amine groups in each repeating unit, which generates immense effect especially on hydrogen bonding types and strength. Due to these unique structural characteristics, PBZs exhibit high tensile strength and modulus (100-125 MPa, and 3.8-4.5 GPa, respectively), and high glass transition temperatures (T g ) (170-340 °C). Accordingly, these materials, particularly rigid ones or those admixed with transition metals, have high service temperatures, char yields, and are stable under acidic/alkali conditions. Unlike the general nature of phenolics, PBZs have low water adsorption stemming from strong intra-molecular hydrogen bonding. Another important aspect is related to their dimensional stability during synthesis. These resins are obtained by ring-opening polymerization of benzoxazine monomers at temperatures between 160-250 °C, sometimes higher, without any additive (Scheme 1) [1][2][3][4][5][6] . It should be emphasized that 1,3-isomers are the only active benzoxazines to undergo such polymerization. According to mechanistic studies, polymerization proceeds via the cationic pathway as oxazine rings have N and O atoms, which are capable of stabilizing cations during polymerization 7-9 .The other appealing side of PBZs is the synthesis of corresponding benzoxazine monomers, which can be accomplished using any suitable phenol, a primary amine, and formaldehyde; therefore, the number of possible benzoxazines is large (Fig. 1) [10][11][12][13][14][15][16] . Apparently, this design flexibility brings about a huge molecular diversity and control of structure and properties of PBZs. For example, crosslinking density of the resins can be increased by introducing dimerizable or polymerizable functionalities on benzoxazines 17,18 . The toughness of PBZs can be manipulated by using long chain amines and other soft or conversely rigid groups [19][20][21][22] . Gas forming moieties can be attached to benzoxazines causing macroporosity to occur during curing; thus, sponge-like materials can be obtained, etc 23,24 . Such suppleness in the properties ...

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Section: Introductionmentioning

confidence: 99%

Recycling and Self-Healing of Polybenzoxazines with Dynamic Sulfide Linkages

Arslan

Kışkan

Yaǧcı

2017

Sci Rep

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“…The wide variety of aromatic bisphenols and monoamines allow for the considerable molecule‐design flexibility of benzoxazines. Some special functional groups, such as acetylene,4, 5 furan,6 allyl,7 propargyl,8 maleimide,9 carboxylic acid,10 methacrylol,11 and amine12 have been incorporated into benzoxazines to provide some desired properties. Diamine‐based benzoxazines are prepared by the condensation of diamine, formaldehyde, and monophenol [Fig.…”

Section: Introductionmentioning

confidence: 99%

Salvage radiation in men after prostate‐specific antigen failure and the risk of death

Cotter

Chen

Moul

et al. 2011

Cancer

101

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BACKGROUND: A survival benefit has been observed with salvage radiation therapy (RT) for prostate-specific antigen (PSA) failure after radical prostatectomy (RP) in men with rapid rises in PSA doubling time (DT, <6 months). Whether such a benefit exits in men with a protracted PSA rise in DT (6 months) is unclear and was examined in the current study. METHODS: Of 4036 men who underwent RP at Duke University between 1988 and 2008, 519 experienced a PSA failure, had complete data, and were the subjects of this study. Univariate and multivariate Cox regression analyses were performed to evaluate whether salvage RT in men with either a rapid (<6 months) or a protracted (6 months) PSA DT was associated with the risk of all-cause mortality adjusting for age at the time of PSA failure, known prostate cancer prognostic factors, and cardiac comorbidity. RESULTS: After a median follow-up of 11.3 years after PSA failure, 195 men died. Salvage RT was associated with a significant reduction in all-cause mortality for men with either a PSA DT of <6 months (adjusted hazard ratio [AHR], 0.53; P ¼ .02) or a PSA DT of 6 months (AHR, 0.52; P ¼ .003). In a subset of patients with comorbidity data at the time of PSA failure, salvage RT remained associated with a significant reduction in all-cause mortality for both men with a PSA DT of <6 months (AHR, 0.35; P ¼ .042) or a PSA DT of 6 months (AHR, 0.60; P ¼ .04). CONCLUSIONS: Salvage RT for PSA DTs less than or in excess of 6 months is associated with a decreased risk in all-cause mortality. Cancer 2011;117:3925-32.

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“…The propargyloxy groups present in polymers are known to undergo un‐catalyzed crosslinking via sigmatropic thermal rearrangement to form 2H‐1‐benzopyran (2H‐chromenes) rings which then undergo polymerization to yield network structures (Supporting Information Figure S5). Furthermore, crosslinking reaction involving propargyloxy group proceeds without the evolution of small volatile compounds and provides void‐free clear films and coatings .…”

Section: Resultsmentioning

confidence: 99%

Thermally Crosslinkable and Chemically Modifiable Aromatic Polyesters Possessing Pendant Propargyloxy Groups

Verma

Maher

Nagane

et al. 2018

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

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New aromatic (co)polyesters containing pendant propargyloxy groups were synthesized by phase transfer‐catalyzed interfacial polycondensation of 5‐(propargyloxy)isophthaloyl chloride (P‐IPC) and various compositions of P‐IPC and isophthaloyl chloride with bisphenol A. FTIR and NMR spectroscopic data, respectively, revealed successful incorporation of pendant propargyloxy groups into (co)polyesters and formation of (co)polyesters with desired compositions. (Co)polyesters exhibited good solubility in common organic solvents such as chloroform, dichloromethane, and tetrahydrofuran and could be cast into transparent, flexible, and tough films from chloroform solution. Inherent viscosities and number average molecular weights of (co)polyesters were in the range 0.77–1.33 dL/g and 43,600–118,000 g/mol, respectively, indicating the achievement of reasonably high‐molecular weights. The 10% weight loss temperatures of (co)polyesters were in the range 390–420 °C, demonstrating their good thermal stability. (Co)polyesters exhibited Tg in the range 146–170 °C and Tg values decreased with increase in mol % incorporation of P‐IPC. The study of non‐isothermal curing by DSC indicated thermal crosslinking of (co)polyesters via propargyloxy groups. The utility of pendant propargyloxy group was demonstrated by post‐modification of the selected copolyester with 1‐(4‐azidobutyl)pyrene, 9‐(azidomethyl)anthracene, and azido‐terminated poly(ethyleneglycol) monomethyl ether via copper(I)‐catalyzed Huisgen 1,3‐dipolar cycloaddition reaction. FTIR and 1H NMR spectra confirmed that click reaction was quantitative. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 588–597

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Thermally Curable Acetylene-Containing Main-Chain Benzoxazine Polymers via Sonogashira Coupling Reaction

Cited by 129 publications

References 46 publications

Recycling and Self-Healing of Polybenzoxazines with Dynamic Sulfide Linkages

Recycling and Self-Healing of Polybenzoxazines with Dynamic Sulfide Linkages

Salvage radiation in men after prostate‐specific antigen failure and the risk of death

Thermally Crosslinkable and Chemically Modifiable Aromatic Polyesters Possessing Pendant Propargyloxy Groups

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