Fei Pan,Yuanhang Xiao,Long Zhang,Jiajing Zhou,Chunhua Wang,Wei Lin
Eco-friendly keratin-based retanning agents have aroused widespread interest in leather manufacturing, because they recycle the biomass wastes for sustainable industry. However, the poor filling effect and binding strength of hydrolyzed keratin from bovine hair wastes limit its application for leather retanning. Here we reported a series of polyacrylate-modified keratin (PMK) retanning agents synthesized from vinyl monomers and bovine hairs via a surfactant-free and UV-initiated polymerization. The obtained spherical PMK retanning agents exhibited ideal characteristics, such as appropriate molecular weight (13–22 kDa) and particle size (86–110 nm), and good colloidal stability in the tanning bath (pH 5.5). We further validated these agents for retanning bovine shoe upper leather. Compared with FB (i.e., a commercial retanning agent), leather retanned with PMK 75 showed increased thickness (∼50%) and reduced Δ b * (∼80%), suggesting excellent filling properties and yellowing resistance. Moreover, the retanning agent afforded the products improved physical properties (e.g., tensile strength ∼17.3 N/mm 2 , tear strength ∼72.7 N/mm and elongation at break ∼75.4%) and sensory properties (e.g., compression thickness ∼0.25 mm and resilience thickness ∼0.21 mm). This work not only offered a robust method for preparing low-cost retanning agents in sustainable industry, but also provided more opportunities for recycling biomass-based wastes aiming to closed-loop economy.
Mao Yang,Haomin Gu,Lang Rui,Huaizhong Yan,Qiang Zhao,Jianyong Wang,Xugang Dang
In this research, a new eco-friendly collagen polypeptide-based foaming agent (CPFC) was prepared via a hydrophobic grafting modification of the collagen polypeptide (CP) from oily acrylic resin, in which the CP was extracted from leather wastes. The molecular structure of CPFC was characterized by FTIR, TGA, XRD, and laser particle size tests. The results showed that the oily acrylic acid molecular chain segments effectively copolymerized with CP, improving the hydrophilic and lipophilic balance of CP molecules. Given the increase of acrylic resin content in CPFC, the surface tension of CPFC at the critical micelle concentration gradually decreased and tended toward the critical value (30 mN/m). The foamability and foaming multiple of 9-CPFC and 7-CPFC reached 535 mL and 31.89 times, respectively. Next, we prepared a CPFC-based foam concrete with a dry density of 500 Kg/m 3 via compounding a mechanical CPFC foaming agent with concrete. The resulting CPFC-based foam concrete was then characterized using a universal testing machine, thermal conductivity meter, ultra-depth 3d microscope, and other analysis techniques. The results indicated that the 5-CPFC foam concrete possessed good foam stability and compatibility. Moreover, the pore size distribution of the foam concrete was uniform, showing a less stringy pore structure, and the water absorption rate and thermal conductivity levels were 27.8 % and 0.61 W/m·K, respectively. The compressive strength of cement was approximately 1.37 MPa, which exceeds the national standard. Moreover, it was found that the CPFC possessed certain retarding properties that were similar to cement, suggesting that it is a highly suitable additive for foam concrete.
Efficient removal of p -arsanilic acid ( p -ASA) from contaminated water is crucial for mitigating arsenic contamination. In this study, a membrane adsorbent named CFM-Zn is developed by retanning Zn on a collagen fiber membrane (CFM). This development leverages the unique physicochemical properties of CFM and the strong affinity of Zn for p -ASA. The membrane is composed entirely of green, low-carbon, and recyclable materials, achieving sustainable removal of p -ASA and embodying the concept of using waste to treat waste for environmental recovery. Remarkably, it exhibits an ultra-high capacity of up to 515.46 mg·g −1 . Additionally, CFM-Zn demonstrates moderate reusability, with effectiveness maintained for at least five cycles. This study could advance the development of bio-based materials for water pollutant removal, expand the applications of leather waste, and significantly promote environmental purification and resource recycling.
危险品化学品经营许可证（带存储）