Natural rubber (NR) has long been plagued by inferior oil resistance and poor thermal degradation at high temperatures. Despite these limitations, NR remains the most widely used elastomer to date. Fluorine-containing compounds have demonstrated excellent oil resistance and thermal stability. However, they generally exhibit poor compatibility with non-polar polymers. After blending, macroscopic phase separation cannot be easily suppressed, leading to the deterioration of the material’s properties. In this study, fluorination modification was performed using hydroxyl-terminated polybutadiene, and the resulting fluorine-modified polybutadiene (3F-PBu-3F) was incorporated into natural rubber. Following sulfur curing, homogeneous phase morphologies were observed in all vulcanizates, which significantly differed from those of previously reported NR/polybutadiene vulcanizates. Additionally, the oil resistance and thermal stability of the NR/3F-PBu-3F vulcanizates were effectively enhanced.
Shuning Zhang,Jiajin Zhou,Yuqing Zhang,Yanlan Bi,Jun Li
Zein and ethyl cellulose (EC) were used as raw materials to prepare a composite coating applied in aqueous systems with mechanical properties, water stability, water solubility (including room-temperature (RT)/high-temperature and neutral/acidic conditions), and oil resistance as evaluation index. Results showed the most suitable conditions were mass ratio of zein/EC at 1:9, 93 % ( v /v) aqueous ethanol, oleic acid as the plasticizer with the amount of 0.3 g/g, and curing temperature at 70 °C. Under these conditions, the tensile strength of composite coating was 4.61 MPa and elongation at break was 21.60 % after 4 weeks of soaking in water. Oil seepage was not observed within 1 week. The water solubility of coating in neutral water was 5.13 % at RT for 24 h, and 3.79 % at 80 °C for 2 min; in acidic water (pH = 4) was 4.54 % at RT for 24 h, and 5.44 % at 80 °C for 2 min. SEM results showed swelling occurred in zein coating after soaking, presenting micropores in soaked zein coating; zein microparticles in composite coating partially broke down and fell off after soaking. Water contact angle results revealed surface hydrophobicity by the following order: EC coating > composite coating > zein coating. FTIR results showed composite coating was physically compounding by hydrophobic interactions and hydrogen bonds.
The oleophilic nature of paper often limits its use in applications that involve direct contact with grease, but now the generation of oil-repellent surfaces has almost universally deployed environmentally detrimental approaches relying on fluorinated compounds. In this paper, non-toxic fluoro-free grease-proof papers coated with sodium alginate (SA)/sodium carboxymethyl cellulose and SA/propylene glycol alginate were prepared, the maximum of kit values reached 9. The coatings completely covered the base paper surface and penetrated into the interfiber networks to some extent, and the modified mechanical properties were obtained. It was found that the lower the air permeability was, the better the oil resistance of the biopolymer coatings on fiber substrate was. For coatings with high surface energy, as the surface energy is dominated by the polar part, the stronger the polarity, the greater the repulsion to oil. The reduction of surface energy can effectively improve the anti-wettability for oil and water.
危险品化学品经营许可证（带存储）