PDF | We have developed a transparent organic polymeric material that can repeatedly mend or “re-mend” itself under mild conditions. Science. Mar 1;() A thermally re-mendable cross-linked polymeric material. Chen X(1), Dam MA, Ono K, Mal A, Shen H, Nutt SR. We have developed a transparent organic polymeric material that can repeatedly mend or “re-mend” itself under mild conditions. The material is a tough solid at.
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Skip to main content. Log In Sign Up. Typical sizes of Nagel, Science In our experiments, the diameters of the needles were 1 mm outer s OD and 0.
The needle-to-collector ties 0. Typical values x 9. Langer, Nature5 The diameter is calculated The use of liquids with much less crosw-linked may lead from the measured current, flow rates, and S Filled symbols repre- Polymer 42, The only way liquid insulators cros-linked be electrosprayed sent situations in which the flow rate of Jain, Biomaterials 21, Fluid olive oil is varied.
Open symbols represent The smallest capsule themrally at- Int. Cross-linmed67 The dispersion of E 58, Two of the authors I. One of the properly controlling the flow rate of oil in and Measurement of Ultrafine Particles, J. Chuchani on this extreme case. Press, Delft, Netherlands, his 77th anniversary.
We have presented a technique to generatepp. This meth- od allows for a precise tailoring of both the outer and the outer-to-inner radius ratio by con- trolling the flow rates of both liquids and the A Thermally Re-mendable applied voltage. A direct application to the pro- duction of monodisperse capsules in the micro- Cross-Linked Polymeric Material meter range has been included.
Although in this Xiangxu Chen,1 Matheus A. The material is a tough solid at ter coated remdndable olive oil, with sizes well in the room temperature and below with mechanical properties equaling those of com- submicrometer range, have been obtained.
Both mercial epoxy resins. In past decades, highly cross-linked polymers properties such as high modulus, high fracture 3. However, these 33, 80 Van hesives, insulators for electronic packaging, stresses 3, 4 due to the formation and prop- Schilfgaarde, J. Biomatter 3, Mathiowitz, Encyclopedia of Controlled Drug De- etc.
Polymegic densely cross-linked struc- agation of cracks. The latter lead to danger- livery Wiley, New York, Mechanical properties of polymer 3 compared with epoxy resins [data taken from p. Dashes indicate data not reliable by method used. Properties Polymer 3 Epoxy resins Unsat. According to the literature covalent bonds at the interface of the mended 19the extent of the DA reaction for a similar parts.
In contrast, in hot plate welding and system could be followed quantitatively by UV crack healing of thermoplastics, only inter- spectroscopy, and the degree of cross-linking matrial Fig. Polymerization degree versus time. The polymerization— meric structural engineering materials 5, 6.
The hot plate welding and crack two decades 15— Assuming the principle cgoss-linked microscopic ular noncovalent interactions chain entangle- eversible polymers, cross-linkable and revers- reversibility applies, this result implies that ments at the interface are responsible for ible groups were attached to linear polymer upon heating the retro-DA reaction is an ac- mending, have been well established 7—9.
In contrast, we report a mac- tion reactions 25 in the polymer network. The concept of self-repair was A thermally reversible DA cycloaddition and an index of refraction of 1. The prepare a polymeric material Scheme 1.
From the results shown tonomic healing of an epoxy resin consists on each molecule, and monomer 2 3M in- in Table 1, it is clear that the mechanical of a clever use of catalytic network formation cludes three maleimide moieties on each mol- properties of this polymer are in the range of of an encapsulated add-monomer, which is ecule A highly cross-linked network commercial, state-of-the-art, cross-linked ep- held within a capsule embedded in the epoxy polymer 3, 3M4F can be formed via the DA oxy resins and unsaturated polyesters 1, But questions remain concerning reaction of furan and maleimide moieties, Solid state reversibility 27was tested the long-term stability of the catalyst and the and thermal reversibility can be accom- via a series of heating cycles that consisted of ability of the material to self-heal multiple plished by the retro-DA reaction M ratio was quenching in liquid nitrogen.
After the heat- poured into a glass mold or materixl on a quartz quench procedure, the samples were heated at 1 Exotic Materials Institute and Department of Chem- plate. The results of five such ence and Engineering, 3Department of Mechanical duced the macromolecular solid. Polymeriza- cycles are shown in Fig. E- duced when cast on quartz matreial.
Thermal reversibility of polymer 3. These results indicate that cross-lunked trum is shown in Fig. Because the latter is quenched sample polymegic disconnected fu- essentially identical to the spectrum in Fig. Modulated DSC data of polymer 3 scan- dothermic peaks in both nonreversing heat ages had themally.
B Sample was network were observed. Solution for crack propagation. In principle, when the 13 C-NMR spectroscopy of the 4F monomer sample is reheated, the furan and maleimide ed full reconnection of polymericc DA partners.
To determine the fracture-mending effi- and retro-DA reactions are reversible in this Upon cycloaddition, the C-3 and C-4 positions ciency of this polymer, tests were per- extended eemendable. This furfuryl acetate with maleic anhydride was used ples by gently tapping a fresh razor blade type of thermal analysis is used to deter- as a model system see structures with Fig.
Application mine and distinguish between i fully re- Solid state 13C-NMR spectra of polymer 3 as a of a load in the direction perpendicular to versible heat effects that are related to the function of thermal cycling are shown in Fig. After structural failure, ed to kinetics 28, Mending effi- ciency of polymer 3.
A Mending efficien- cy obtained by frac- ture toughness test- ing of compact ten- sion test specimens. Values for the original and healed fracture toughness were de- termined by the prop- agation of the starter crack along the mid- dle plane of the spec- imen at the critical load. B Image of a broken specimen be- fore thermal treat- ment.
A thermally re-mendable cross-linked polymeric material. – Semantic Scholar
C Image of the specimen after thermal treatment. D SEM image of the surface of a healed sample: E Enlarged image of the boxed area in D.
Considering that the specimens were the maleimide monomer melts at too high a tant Fig. After thermal treatment, split into two separate pieces and kept under temperature, is colored yellowand is insolu- only a slight interface mismatch was ob- the same atmospheric pressure sometimes as ble in monomer 4F. Before the images were taken, Cr 3 composite 4.
Another factor, which should cations but close to ideal for others, such as nm and Au 30 nm were deposited onto the affect healing efficiency, is the uniformity self-mending electronic packaging, where surface via electron-beam evaporation. Shown and amount of applied cross-linkeed. Our prelim- cracking occurs due polymefic differences in thermal on the left side of Fig.
The fracture cross-lunked surface was scraped with a fresh razor blade.
Within experimental error, the 2. The second and third terials Elsevier, Amsterdam,pp. Structure and Strength minor defects, suggesting remarkable mend- crack plane.
However, it was not uncommon Hanser Gardner, Cincinnati,pp. Figure 5E is thermzlly enlarged im- to observe cracking in a region adjacent to a 8. The latter shows the interface scar from a previous crack. This is probably Eng. B 32, To test oxidative degradation of the polymer A composite with dual phase structure of linear polystyrene and polymerci vinyl ester was studied.
A thermally re-mendable cross-linked polymeric material.
Of a polymer specimen are plotted in Fig. Not surprisingly, the accu- testing.
Within the experimental error of the is from polystyrene chain interpenetration. Sottos, Smart Structures and Materials C33 3 The ultrasonics method takes cited in this reference, and Pc is the critical load thermalky The fracture energy GIc value can be Saegusa, Macromolecules 23, gation velocity of ultrasound through the material.