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In this study, 4,4′-diaminodiphenylmethane bismaleimide (BMI) was used as the matrix and epoxy resin (EP) and polyether sulfone (PES) were used as the toughening agent. PES/EP-BMI two-phase composites were prepared; they could be applied in more fields. The SEM results and energy spectrum analysis show a strong interaction between PES and EP-BMI molecules, and the surface of the two phases is fuzzy. PES dispersed uniformly in the EP-BMI matrix as the dispersed phase. The interface among phases is blurred and shows a mutual penetrating phenomenon. Furthermore, the cross-section of cracks is rough, and the directions change. This is a typical ductile fracture morphology. The highest bending strength and impact strength of PES/EP-BMI composite material are 144.9 MPa and 19.7 kJ/m2, 41.2% and 90% increases copmared with those of EP-BMI matrix resin, respectively, when the content of PES is 4 wt%. Moreover, the decomposition temperature of the composite reaches 407°C, 9°C higher than that of EP-BMI. However, excess PES has a negative effect on the thermal decomposition temperature. The addition of PES increases the dielectric constant and dielectric loss of composites though they increase only slightly. The comprehensive properties of composites are at their best when the content of PES is 4 wt%. Overall, this study facilitates the applications of PES/EP-BMI composites in a broad range of fields. [ABSTRACT FROM AUTHOR]

Sodium montmorillonite (MMT) was modified by octadecyl trimethyl ammonium chloride (OTAC) via cation exchange to obtain organo-montmorillonite (OMMT), Al2O3 was treated by KH-550 (3-Aminopropyltriethoxysilane) to get KH-Al2O3. The polyurethane elastomer (PUE) was synthesized with 4,4′-diphenylmethane diisocyanate (MDI), polypropylene glycol (PPG) and 1,4-butanediol (BDO) as the raw materials. And then, OMMT/KH-Al2O3/PUE composite was prepared by the prepolymer method; PUE was the matrix, OMMT and KH-Al2O3 were reinforcements. The micro-morphology and mechanical properties of OMMT/KH-Al2O3/PUE composites were measured and analyzed. The results of FT-IR and XRD showed that OTAC had been introduced into MMT layer and the layer spacing of OMMT had increased. The KH-550 had successfully grafted to the surface of Al2O3 to obtain KH-Al2O3. The TEM results demonstrated the interaction between OMMT and KH-Al2O3, weakening the interaction between the same molecules and the OMMT sheet was further peeled off. The SEM images displayed that a specific ratio of OMMT and KH-Al2O3 had excellent dispersion in the PUE matrix. The mechanical properties of OMMT/KH-Al2O3/PUE composites were significantly better than those of OMMT/PUE and KH-Al2O3/PUE composite. The maximum tensile strength, elongation at break and tensile strength at break are 21.82 MPa, 668% and 19.98 MPa, respectively, which were 43.8%, 29.2% and 36.8% higher than that of PUE matrix, when the content of inorganic components was 3 wt% and the mass rate of OMMT to KH-Al2O3 was 1:1. This composite material is a kind of excellent polyurethane elastomer and widely is maybe used in mechanical accessories, pipe, mining and metallurgy industries. [ABSTRACT FROM AUTHOR]