Shape memory polybenzoxazines based on polyetheramine

Liu, Yanfang; Huang, Jinbai; Su, Xuehui; Han, Mei; Li, Huan; Run, Mingtao; Song, Hongzan; Wu, Yonggang

doi:10.1016/j.reactfunctpolym.2016.03.010

Cited by 37 publications

(34 citation statements)

References 52 publications

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“…The structure of the benzoxazine monomers was further verified by 13 Single X-ray Analysis. Structures of the BZ2s were also confirmed with the single crystal X-ray diffraction analysis.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Synthesis and Thermal Properties of Difunctional Benzoxazines with Attached Oxazine Ring at the Para-, Meta-, and Ortho-Position

2017

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To investigate the role of position of oxazine ring in the benzoxazine backbone on their ring-opening polymerization (ROP) and thermal stability of resulting polybenzoxazine, we have synthesized difunctional monomers solely containing benzoxazine moieties (BZ2) with attached oxazine ring at the para-, meta-, and ortho-position. The ROP was examined by DSC analysis, which revealed a reduction in curing temperature in the order of meta (225°C) < ortho (239°C) < para (251°C). The differences in structural and geometrical parameters were investigated by NMR ( 1 H, 13 C, 1 H− 1 H NOESY) and X-ray crystallography analysis. The electronic effects and the intramolecular interaction between oxazine ring and aromatic hydrogen were higher when the attached oxazine ring was at the meta-position. The differences in their positioning also changed their ROP mechanism, an unusual intramolecular polymerization was observed in meta, while in ortho and para the polymerization proceeded in a regular manner. A curing mechanism responsible for lower curing temperature and faster ROP in meta has been proposed, which involves an intramolecular electrophilic substitution of iminium ion, resulting in aza-cyclic rings along with classical phenolic Mannich bridges in the networked structure. The cured resin showed a high T g and in the order of para (291°C) > meta (270°C) > ortho (266°C). Even though meta-PBZ2 displayed an earlier degradation with T d10 of 358°C as compared to para and ortho (T d10 : 373°C) due to aza-cyclic rings, the main backbone degradation was observed to be coinciding in all PBZ2s at 417°C with a char yield of 57% at 600°C. Thus, changing position of oxazine ring to "meta" in the backbone is a beneficial strategy to have a low curing benzoxazine without sacrificing the thermal stability of resulting polybenzoxazine. ■ INTRODUCTIONPolybenzoxazines, a relatively new phenolic-type thermosetting resin, in which the cross-linked network is constructed by linking phenolic moiety with Mannich bridges (−CH 2 −NR− CH 2 −). These resins has gained enormous interest in researchers from both academia and industry due to their outstanding properties including near zero volumetric shrinkage upon curing, minimal water absorption, low flammability, high glass transition temperature usually much higher than its curing temperature, fast physical and mechanical property buildup even at low conversion, etc. These unique properties are due to the existence of inter/intra molecular hydrogen bonding in the cross-linked network, specifically the very stable six-membered intramolecular OH---N hydrogen bonding. Moreover, the simplicity in benzoxazine monomer synthesis make them more attractive, which involves Mannich condensation of phenol, primary amine, and formaldehyde. 1−5 The tremendous molecular design flexibility offers myriad of modification in to the structure simply by changing suitably functionalized phenol/amines to develop polybenzoxazines with desired properties for particular applications. 6−13 Unlike traditional phenolics, the ...

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“…The structure of the benzoxazine monomers was further verified by 13 Single X-ray Analysis. Structures of the BZ2s were also confirmed with the single crystal X-ray diffraction analysis.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Synthesis and Thermal Properties of Difunctional Benzoxazines with Attached Oxazine Ring at the Para-, Meta-, and Ortho-Position

2017

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“…The reaction enthalpy of o C‐aptmds, m C‐aptmds, and p C‐aptmds are 162.5, 190.4, 183.0 J/g, respectively. Therefore, the reactivities of the benzoxazine monomers in the polymerization are defined by the methyl position on the starting phenols …”

Section: Resultsmentioning

confidence: 99%

“…Of course, owing to the molecular design flexibility of benzoxazines, it is possible to prepare smart materials from pristine benzoxazines. Recently, we synthesized a series of benzoxazines containing flexible SiOSi and COC units, and the resultant polybenzoxazines exhibit thermally induced SMEs …”

Section: Introductionmentioning

confidence: 99%

Effect of methyl position on the dynamic mechanical and shape‐memory properties of cresol‐based polybenzoxazines

Liu

Song

et al. 2017

J of Applied Polymer Sci

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Three difunctional benzoxazines were synthesized from cresol isomers (o-, m-, and p-methylphenols), 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, and formaldehyde. The ring-opening polymerization temperature decreases in the order of ortho-, para-, and meta-positions of methyl group for the benzoxazine monomers, whereas the glass transition temperature increases in the order of ortho-, para-, and meta-positions of methyl group for the resultant polybenzoxazines. In addition, the polybenzoxazines exhibit one-way dual-shape-memory behavior in response to changes in temperature, and the shape-memory effects are evaluated by tensile and bending tests with a temperature program based on glass transition temperature. The o-and p-cresol-based polybenzoxazines exhibit higher shape-memory performance than their m-cresol-based analogue/counterpart. V C 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45443.

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“…Recently, we synthesized a series of benzoxazines containing flexible –C–O–C– and –Si–O–Si– units, and the resultant polybenzoxazines exhibit thermally induced shape memory effect (SME) based on glass‐transition temperature ( T g ) . The shape memory properties of the polybenzoxazines are excellent under tensile and bending modes.…”

Section: Introductionmentioning

confidence: 99%

“…o ‐Allylphenol‐ and o ‐cresol‐polyetheramine‐based benzoxazines ( o AP‐pea and o C‐pea) are from ortho‐substituted phenols, and the resultant polybenzoxazines [poly( o AP‐pea) and poly( o C‐pea)] exhibit excellent shape recovery ratios under free conditions in bending and tensile tests but relatively low under motion constraints in tensile test . From a structure point of view, benzoxazines based on ortho‐substituted phenols tend to form polybenzoxazines with low crosslinking density.…”

Section: Introductionmentioning

confidence: 99%

Dynamic mechanical and shape memory properties of copolymers based on polyetheramine‐type benzoxazines and diglycidylether of bisphenol‐A

Shen

et al. 2018

J of Applied Polymer Sci

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Two series of benzoxazine/epoxy copolymers are prepared from polyetheramine-type benzoxazines and diglycidyl ether of bisphenol A (DGEBA) in various weight ratios. Each copolymer appears a single glass-transition temperature (T g ), and the T g shows a systematic increase with increasing DGEBA content for both copolymer systems, but copolymers with low DGEBA content show respectively lower T g s than the corresponding pristine polybenzoxazines. Compared to the corresponding pristine polybenzoxazines, the effect of DGEBA content on the variation in T g of the copolymers depends on the substituent structure of benzoxazines. The two series of copolymers exhibit one-way dual shape memory effect based on T g , and the shape memory effect is affected by both the substituent structure of benzoxazines and the content of DGEBA. Under motion constraints in tensile deformation mode, copolymers with low DGEBA content exhibit high shape recovery ratios (91.0-96.1%) over the corresponding polybenzoxazines (84.5%), whereas copolymers with high DGEBA content show relatively low shape recovery ratios (75.0-84.7%).

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Shape memory polybenzoxazines based on polyetheramine

Cited by 37 publications

References 52 publications

Synthesis and Thermal Properties of Difunctional Benzoxazines with Attached Oxazine Ring at the Para-, Meta-, and Ortho-Position

Synthesis and Thermal Properties of Difunctional Benzoxazines with Attached Oxazine Ring at the Para-, Meta-, and Ortho-Position

Effect of methyl position on the dynamic mechanical and shape‐memory properties of cresol‐based polybenzoxazines

Dynamic mechanical and shape memory properties of copolymers based on polyetheramine‐type benzoxazines and diglycidylether of bisphenol‐A

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