Component modulation of bamboo scraps enhances interfacial compatibility and strength of thermal insulation composites

The combination of bamboo waste and magnesium oxychloride (MOC) cement is a promising pathway to obtain green, lightweight construction materials. However, bamboo scraps tend to hinder the formation of high-quality pores within composites, and the insufficient bonding strength at the inorganic-organic interface leads to poor performance. We present an eco-friendly ammonium carbonate (AC) treatment strategy to replace traditional processes that use NaOH solution to modulate the components of bamboo. The AC treatment removed substances that interfered with hydration and softened the rigid bamboo skeleton, attenuating its negative effects on pore formation. Furthermore, the exposure of hydrophilic groups facilitated the growth of 5-phase crystals into surface micropores, which created a robust anchoring effect that markedly reduced interfacial defects and brittleness. The composites prepared with this method exhibited a 45% increase in compressive strength, a 12% improvement in the softening coefficient, and a 15% reduction in thermal conductivity, endowing them with enhanced mechanical properties, improved water resistance, and excellent thermal insulation performance. This strategy provides a reference for preparing green, high-performance, biomass-based lightweight composites, as well as for interface modification and high-quality pore structure regulation.