The strategy of using sustainable biomass resources instead of traditional petrochemical products has been established as an environmentally friendly way to achieve the “green rubber” industry. Meanwhile, rubber antioxidants possessing high efficiency, long-lasting protection, migration resistance, and green multifunctional properties have attracted intensive investigation for rubber protection. Herein, a naturally extracted substance of tea polyphenol (TP)-functionalized halloysite nanotubes (HNTs), which generates the slow release of free-radical capturing activity and excellent interfacial interaction in the natural rubber matrix, is fabricated by vacuum-pumping and surface-decorating methods (denoted as HNTs-s-TP). Interestingly, the nontoxic and natural antioxidant HNTs-s-TP exhibited remarkable thermo-oxidative aging resistance and stability in a natural rubber (NR) matrix compared to that of TP directly pumped into the tubes due to the further modification of the chemical anchor TP on the outer surface of HNTs. In addition, we have systematically investigated the mechanism for highly efficient and sustainable antioxidation in the rubber matrix via the natural antioxidant HNTs-s-TP derived from the constructed galloyl structure. We envision that this new natural antioxidant fabrication technology will provide significant insights into the innovation for the construction of green and eco-friendly functionalized rubber additives.

A straight-forward method was exploited to construct a multifunctional hybrid photoinitiator by supporting 2-hydroxy-2-methylpropiophenone (HMPP) onto a nano-silica surface through a chemical reaction between silica and HMPP by using (3-isocyanatopropyl)-triethoxysilane (IPTS) as a bridge, and this was noted as silica-s-HMPP. The novel hybrid-photoinitiator can not only initiate the photopolymerization but also prominently improve the dispersion of nanoparticles in the polyurethane acrylate matrix and enhance the filler-elastomer interfacial interaction, which results in excellent mechanical properties of UV-cured nanocomposites. Furthermore, the amount of extractable residual photoinitiators in the UV-cured system of silica-s-HPMM shows a significant decrease compared with the original HPMM system. Since endowing the silica nanoparticle with photo-initiated performance and fairly lower mobility, it may lead to a reduction in environmental contamination compared to traditional photoinitators. In addition, the hybrid-photoinitiator gives rise to an accurate resolution object with a complex construction and favorable surface morphology, indicating that multifunctional nanosilica particles can be applied in stereolithographic 3D printing.