A New Route to Highly Stretchable and Soft Inorganic–Organic Hybrid Elastomers Using Polydimethylsiloxane as Crosslinker of Epoxidized Natural Rubber

Abstract

Sulfur or peroxide crosslinking is the most common and conventional method to develop elastomeric materials. A new approach to crosslink epoxidized natural rubber (ENR) by aminopropyl terminated polydimethylsiloxane (AT‐PDMS) is described, intending to develop a new kind of hybrid organic–inorganic elastomers. The curing reaction is accelerated by using hydroquinone as a catalyst. The formation of the hybrid structure is evident from the appearance of two glass transition temperatures, at −1 and −120 °C, for the ENR and PDMS phases, respectively. The curing reaction is found to be of first order with respect to amine concentration with the estimated activation energy of ≈62 kJ mol−1. Comparing the mechanical properties to a typical ENR‐sulfur system leads to the conclusion that the ENR/AT‐PDMS hybrid structure is highly stretchable and soft, as demonstrated by its relatively higher strain at failure (up to ≈630%), and lower hardness and modulus values. The higher stretchability and soft nature of the material are achieved by introducing flexible PDMS chains during the curing process resulting to a hybrid elastomer networks. This kind of soft but robust materials can find several applications in diverse fields, such as soft robotics, flexible, and stretchable electronics.

Strengthened Poly(vinylidene fluoride)/Epoxidized Natural Rubber Blend by a Reactive Compatibilizer Based on an Amino Acid-Modified Fluorocarbon Elastomer

“…The absorbance ratio of the C–F group in extracted ENR50 increased with the AHA content, which confirms the grafting of FKM-AHA with ENR50 during blending. Moreover, as shown in Figure S5, the shift of the epoxide group band from 877 cm –1 to a lower wavenumber of 873 cm –1 indicates the grafting reaction of FKM and ENR50, which was induced by a ring-opening reaction of the epoxide group in ENR50. , …”

“…Moreover, as shown in Figure S5, the shift of the epoxide group band from 877 cm −1 to a lower wavenumber of 873 cm −1 indicates the grafting reaction of FKM and ENR50, which was induced by a ring-opening reaction of the epoxide group in ENR50. 16,53 3.3. Effect of Reactive Compatibilizer Loading.…”

“…In addition, ENR50 extracted from the blends also revealed a shift in FTIR spectra of epoxide to a lower wavenumber, as shown in Figure S7, suggesting a ring-opening reaction of the epoxide group in ENR and interaction between ENR50 and FKM. 16,53 Moreover, acid hydrolysis etching, solvent extraction, and graft ratio for the blends with various FKM-AHA10 contents are listed in Table S2. It can be seen that the GR value increased with the FKM-AHA10 content, which conclusively supports the argument that FKM-AHA can act as the reactive compatibilizer and in situ reaction in PVDF/ENR50 blends, as described earlier.…”

Ultrafast synthesis of silicone elastomers using silsesquioxane cages as crosslinkers

“…11–13 So far, the synthesis of silicone elastomers from the above mentioned materials has required several steps, the requirement of a template, fillers, and a long reaction time. 14–18…”

“…[11][12][13] So far, the synthesis of silicone elastomers from the above mentioned materials has required several steps, the requirement of a template, fillers, and a long reaction time. [14][15][16][17][18] Herein, a superfast combination reaction between a cyclic tetrasiloxane and POSS can form a silicone elastomer via an anionic ring-opening polymerization. Cross-linked siloxane/ silsesquioxane elastomers (CSSEs) were successfully synthesized in one step in dimethylformamide (DMF) within 15 min at 70 1C without any template or filler and with only K 2 CO 3 as a base catalyst (Scheme 1 and Video S1, ESI †).…”