Research on the Resourceful and Efficient Recycling Technology of Waste Thermal Insulation Pipe Material.

This study was conducted to explore a new method for degrading and recycling waste chemical pipe insulation and cooling materials. A chemical degradation method was employed, utilizing alkali metal catalysts and a two-component alcoholysis system consisting of specific ratios of diethylene glycol and butylene glycol. The system effectively degraded the polyisocyanurate (PIR) insulation with the aim of reusing the waste material.

The Catalytic Degradation of Waste PU and the Preparation of Recycled Materials.

In this paper, we investigated the efficient metal-free phosphorus-nitrogen (PN) catalyst and used the PN catalyst to degrade waste PU with two-component binary mixed alcohols as the alcohol solvent. We examined the effects of reaction temperature, time, and other factors on the hydroxyl value and viscosity of the degradation products; focused on the changing rules of the hydroxyl value, viscosity, and molecular weight of polyols recovered from degradation products with different dosages of the metal-free PN catalyst; and determined the optimal experimental conditions of reaction temperature 180 °C, reaction time 3 h, and PN dosage 0.08%.

Application of Whisker-Toughened Aerogel to Recycling of Used Polyurethane Sheets.

In this study, a new environmentally friendly and efficient method for recycling and reusing waste polyurethane sheets is proposed. SiO aerogel was prepared using the sol-gel method, and mullite whiskers were introduced to enhance its toughness. The whisker-toughened aerogel was used in the degradation of waste polyurethane to produce modified recycled polyol, which was subsequently used to prepare recycled polyurethane foam insulation material.

Research on the Application of New Building Recycled Insulation Materials for Walls.

In this paper, a new type of recycled polyurethane material is used as a new type of wall insulation material, and the new building insulation wall made of this paper has high efficiency thermal insulation and energy-saving characteristics and also has certain environmental significance. The thermal conductivity of the new building cold insulation recycled polyurethane material is 0.023 W/(m·K), and the thermal conductivity of the new building insulation wall prepared is 0.

The Aging Behavior and Life Prediction of CFRP Rods under a Hygrothermal Environment.

Carbon fiber-reinforced polymer (CFRP) composites have been widely used in civil engineering structures due to their excellent mechanical and durability properties. The harsh service environment of civil engineering leads to significant degradation of the thermal and mechanical performances of CFRP, which then reduces its service reliability, service safety, and life. Research on the durability of CFRP is urgently needed to understand the long-term performance degradation mechanism.

The Long-Term Interfacial Evolution and Prediction of Carbon- and Glass-Fiber-Reinforced Epoxy Hybrid Rods under a Hygrothermal Environment.

In order to promote the engineering applications of carbon- and glass-fiber-reinforced epoxy hybrid rods, it is necessary to fully understand its long-term hygrothermal durability. In the present study, the water absorption behaviors of a hybrid rod in a water immersion environment are studied experimentally, the degradation rules of the mechanical properties are obtained, and establishing a life prediction model is attempted. The water absorption of the hybrid rod confirms to the classical Fick's diffusion model, and the water absorption concentration is determined by radial position, immersion temperature, and immersion time.

Precipitation behavior in a nitride-strengthened martensitic heat resistant steel during hot deformation.

The stress relaxation curves for three different hot deformation processes in the temperature range of 750-1000 °C were studied to develop an understanding of the precipitation behavior in a nitride-strengthened martensitic heat resistant steel (Zhang et al., Mater. Sci.