Mobility, Miscibility, and Microdomain Structure in Nanostructured Thermoset Blends of Epoxy Resin and Amphiphilic Poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) Triblock Copolymers Characterized by Solid-State NMR

Sun, Pingchuan; Dang, Qin-Qin; Li, Baohui; Chen, Tiehong; Wang, Yinong; Lin, Hai; Jin, Qinhan; Ding, Datong; Shi, An‐Chang

doi:10.1021/ma0505979

Cited by 80 publications

(77 citation statements)

References 69 publications

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“…The expulsion of the epoxy miscible block from the epoxy matrix, as a result of the curing process, has also been observed in other templated thermoset systems utilizing a nonreactive block copolymer additive. 19,30,43,44 This mechanism for the morphological orderorder phase transition described above can be used to describe the cure induced spherical to wormlike micelle transition observed in this work. In these systems, the epoxy matrix itself acts as an increasingly poor solvent for the micelle corona as the curing process progresses.…”

Section: Resultsmentioning

confidence: 90%

Control of the block copolymer morphology in templated epoxy thermosets

Hermel-Davidock¹,

Tang²,

Murray³

et al. 2007

J Polym Sci B Polym Phys

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It has been found that by the addition of low concentrations of an amphiphilic block copolymer to an epoxy resin, novel disordered morphologies can be formed and preserved through curing. This article will focus on characterizing the influence of the block copolymer and casting solvent on the templated morphology achieved in the thermoset sample. The ultimate goal of this work is to determine the parameters that would control the microphase morphology produced. Epoxy resins blended with a series of amphiphilic block copolymers based on hydrogenated polyisoprene (polyethylene-alt-propylene or PEP) and polyethylene oxide (PEO), specifically, were investigated. In this article, the cure-induced order-order phase transition from the spherical to wormlike micelle morphology will also be discussed. It is proposed that the formation of the wormlike micelle structure from the spherical micelle structure is similar to the phase transition behavior that occurs in dilute block copolymer solutions as a function of the influence of the solvent on micelle morphology.

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Section: Resultsmentioning

confidence: 90%

Control of the block copolymer morphology in templated epoxy thermosets

Hermel-Davidock¹,

Tang²,

Murray³

et al. 2007

J Polym Sci B Polym Phys

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“…This observation is quite opposite to the dipolar filter under static conditions, where the dipolar filter strength increases (resulting in faster signal decay) with increasing the inter-pulse delay. 48,49 However, for the rotorsynchronized dipolar filter, the dipolar filter strength decreases with increasing the inter-pulse delay (i.e., increasing n with n ≤ 12 and n 3k) due to the MAS interference. According to the decay rate of signals from the rigid NH 3 + and the most mobile CH 3 given in Fig.…”

Section: Resultsmentioning

confidence: 99%

“…In principle, the proton transverse relaxation time in solid systems is mainly determined by the 1 H-1 H dipolar couplings, which means that the proton signals experiencing strong dipolar couplings will be filtered out first. Because of this reason, the 12-pulse dipolar filter sequence has been utilized in the investigation of the mobility of absorbed ligands on the surface of nanoparticles, 46,47 to measure the domain size in a multiphase system, 44,48,49 and the chain interpenetration and compatibility in polymer glasses. 50,51 In order to overcome the destructive interferences between MAS averaging and RF-pulses of the dipolar filter, here we utilized a rotor-synchronized dipolar filter with C N v n symmetry to filter out signals from rigid components of the system.…”

Section: Pulse Sequencementioning

confidence: 99%

Dynamics-based selective 2D 1H/1H chemical shift correlation spectroscopy under ultrafast MAS conditions

Zhang

Ramamoorthy

2015

The Journal of Chemical Physics

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Dynamics plays important roles in determining the physical, chemical, and functional properties of a variety of chemical and biological materials. However, a material (such as a polymer) generally has mobile and rigid regions in order to have high strength and toughness at the same time. Therefore, it is difficult to measure the role of mobile phase without being affected by the rigid components. Herein, we propose a highly sensitive solid-state NMR approach that utilizes a dipolar-coupling based filter (composed of 12 equally spaced 90• RF pulses) to selectively measure the correlation of 1 H chemical shifts from the mobile regions of a material. It is interesting to find that the rotor-synchronized dipolar filter strength decreases with increasing inter-pulse delay between the 90• pulses, whereas the dipolar filter strength increases with increasing inter-pulse delay under static conditions. In this study, we also demonstrate the unique advantages of proton-detection under ultrafast magic-angle-spinning conditions to enhance the spectral resolution and sensitivity for studies on small molecules as well as multi-phase polymers. Our results further demonstrate the use of finite-pulse radio-frequency driven recoupling pulse sequence to efficiently recouple weak proton-proton dipolar couplings in the dynamic regions of a molecule and to facilitate the fast acquisition of 1 H/ 1 H correlation spectrum compared to the traditional 2D NOESY (Nuclear Overhauser effect spectroscopy) experiment. We believe that the proposed approach is beneficial to study mobile components in multi-phase systems, such as block copolymers, polymer blends, nanocomposites, heterogeneous amyloid mixture of oligomers and fibers, and other materials. C 2015 AIP Publishing LLC. [http://dx

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“…38,39 Sun et al 40 characterized the heterogeneous dynamics, miscibility, and microdomain structure in nanostructured thermoset blends of ER and amphiphilic poly(ethylene oxide) (PEO)-block-poly(propylene oxide) (PPO)-block-PEO triblock copolymers with solid NMR methods. On the basis of the 1 H spin diffusion and DSC experiments, a possible model for the dynamics and microphase structure in the cured ER/PEO-PPO-PEO blends was proposed ( Figure 2).…”

Section: Overview Of Methods Used To Study the Pips Of Thermosetsmentioning

confidence: 99%

Polymerization‐induced phase separation and resulting thermomechanical properties of thermosetting/reactive nonlinear polymer blends: A review

Liu

2012

J of Applied Polymer Sci

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Thermosets, which have a highly crosslinked structure, play a pivotal role in high-performance composite materials because of their excellent mechanical properties, including their high modulus, high strength, and high glass-transition temperature. In general, however, thermosets are brittle materials with a toughness and elongation at break that are unsatisfactory for many applications, especially at high temperatures. The key factor that can greatly influence the toughness of a thermoset material is its cured microstructure or nanostructure. Recently, it has been revealed that the introduction of a reactive modifier into a multicomponent thermosetting prepolymer is a versatile way to finely tune the polymerization-induced phase separation (PIPS) and the microstructure and thermomechanical properties of the resulting thermosets. This review focuses first on the advancement of the methods used to study the PIPS of thermosetting prepolymers. I go on to discuss factors influencing the thermodynamic and the kinetic behavior of PIPS and the resulting morphology and thermomechanical properties of thermosetting blends obtained when nonlinear reactive modifiers are incorporated.

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Mobility, Miscibility, and Microdomain Structure in Nanostructured Thermoset Blends of Epoxy Resin and Amphiphilic Poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) Triblock Copolymers Characterized by Solid-State NMR

Cited by 80 publications

References 69 publications

Control of the block copolymer morphology in templated epoxy thermosets

Control of the block copolymer morphology in templated epoxy thermosets

Dynamics-based selective 2D 1H/1H chemical shift correlation spectroscopy under ultrafast MAS conditions

Polymerization‐induced phase separation and resulting thermomechanical properties of thermosetting/reactive nonlinear polymer blends: A review

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