Preparation of degradable bio-based silicone/epoxy hybrid resins towards low dielectric composites

Epoxy resins are well-known adhesive materials, however, the high dielectric constant (Dk) limited their application in microelectronic devices. Additionally, non-degradability is a bottleneck for all thermosetting resins, and the discarded resins posed the great threat to environment. Herein, a bio-based eugenol epoxy was grafted onto the polymethylhydrosiloxane (PMHS-x) main chain via a hydrosilylation reaction to simultaneously lower the D-k and enable degradability. The curing kinetics of bio-based silicone/epoxy hybrid resins with methyl hexahydrophthalic anhydride (MHHPA) or 4,4'-diaminodiphenylmethane (DDM) were studied. The cured resins exhibited low D-k and hydrophobicity by taking advantage of the low polarity, large molecular volume and high dissociation energy of the siloxane segments. The polysiloxane degradation process took place under alkaline conditions, allowing the retrieval of reinforced fibers from the composites. To better illustrate the superiority of the bio-based silicone/epoxy hybrid resins, quartz fiber reinforced composites were prepared. Compared to the commercial epoxy based composite, the impact strength of the PMHS-x with a silicon hydrogen content of 0.8 x 10(-2) mol.g(-1) was increased by 26.5 %, meanwhile, the D-k was decreased by 16.7 %. The bio-based silicone/epoxy hybrid resins not only alleviated the environmental pollution but also provided a reliable approach for fiber recycling from epoxy composites. The low polarity and degradability were integrated into bio-based silicone/epoxy hybrid resins, which provided a novel way to prepare environment-friendly materials suitable for microelectronic devices.

Automated summary

In this study, a bio-based eugenol epoxy was grafted onto the polymethylhydrosiloxane (PMHS-x) main chain to develop a novel environmentally friendly silicone/epoxy hybrid resin. The hybrid resin exhibited low dielectric constant (D-k) and hydrophobicity, and the polysiloxane degradation process allowed for the retrieval of fibers from the composites. Compared to commercial epoxy-based composites, the hybrid resin showed higher impact strength and lower D-k, providing a reliable material option for microelectronic devices.