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In this work, a series of siloxane epoxy resins (E3074) were synthesized through reaction of poly(methylphenylsiloxane) (DC-3074) with epoxy resin. The chemical structure of the resultant epoxy resin was determined by FTIR, GPC, and epoxy equivalent weight (EEW) tests. The mechanical measurements indicated that the tensile strength of E3074 was lower than that of neat epoxy resin after modification, while their elongations at break improved markedly when compared with that of epoxy resin. SEM revealed that the particle size of silicone had a significant effect on the mechanical properties of the modified epoxy resin. TGA results showed that the thermal stability of E3074 serials was better than that of epoxy resin. The char residue of E3074 at 600 C increased with the incremental content of silicone. DMA tests displayed that the addition of silicone effectively enhanced the damping properties of epoxy resin.

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In this paper, a facile method was adopted to synthesize polycarboxylate (PC) superplasticizers which rendered excellent initial fluidity and workability of mortar in 1 hour. Micro-crosslinking was introduced in the PC molecules and the ester groups in crosslinker can form carboxyl groups in the hydration solution of cement. The micro-crosslinked PC (MPC) superplasticizer was synthesized from butenyl alkylenepolyoxyethylene-polyoxypropylene ether, sodium methacrylate, acrylic acid with trimethylolpropane triacrylate (TMPTA) as the crosslinker in water medium. The effect of monomer content and the dosage of crosslinker on the performance of MPC were studied. Fourier transform infrared spectroscopy and dynamic light scattering analyses were conducted to characterize the molecular structure of MPC. The fluidity of mortar in 1 hour was tested to study the fluidity and the retention in fluidity of mortar with the presence of MPC, indicating that micro-crosslinking with trifunctional crosslinker TMPTA was an effective way to improve the fluidity retention without sacrificing the initial fluidity. Investigations on early hydration of cement with MPCs were performed using XRD and TGA. Results showed that the addition of MPCs can slightly improve the degree of early hydration.