文献类型：期刊文献

英文题名：Developing polysulfide castor oil-based polymer coating for controlled-release urea fertilizers

作者：Feng, Guo-dong[1,3] Ma, Yan[1] Liu, Hao-hao[2] Zhang, Meng[1] Jia, Pu-you[1] Hu, Li-hong[1,2] Liu, Cheng-guo[1] Hu, Yun[1] Zhou, Yong-hong[1,2,4]

第一作者：冯国东;Feng, Guo-dong

通信作者：Zhou, YH[1]

机构：[1]Chinese Acad Forestry, Inst Chem Ind Forestry Prod, Nanjing 210042, Peoples R China;[2]Nanjing Forestry Univ, Coinnovat Ctr Efficient Proc & Utilizat Forest Res, Nanjing 210042, Peoples R China;[3]Key Lab Biomass Energy & Mat, Nanjing 210042, Jiangsu, Peoples R China;[4]Chinese Acad Forestry, Inst Chem Ind Forestry Prod, 16 Suojin 5th Village, Nanjing 210042, Peoples R China

年份：2024

卷号：190

外文期刊名：PROGRESS IN ORGANIC COATINGS

收录：;EI(收录号：20241115713976);Scopus(收录号：2-s2.0-85186961904);WOS:【SCI-EXPANDED(收录号:WOS:001202734500001)】；

基金：We submit the enclosed manuscript entitled "Developing polysulfide castor oil-based polymer coating for controlled-release urea fertilizers", which we wish to be considered for publication in "Progress in Organic Coatings". I would like to declare on behalf of my co-authors that We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted. The work described was original research that has not been published previously, and not under consideration for publication elsewhere, in whole or in part. All the authors listed have approved the manuscript that is enclosed. The authors are grateful for the financial support from the National Key R & D Program of China (Grant No. 2022YFD2200702-1).

语种：英文

外文关键词：Polysulfide; Castor oil -based polyols; Controlled -release fertilizer; Coated urea; TG-FTIR; Degradation

摘要：Urea coated with only sulfur is prone to cracking and exhibits poor controlled -release characteristics. Conversely, employing polymers as the sole coating material is expensive and not easily biodegradable. To address these challenges, polysulfide castor oil-based polyols with varying sulfur contents (PSOPs-30 %, PSOPs-40 %, PSOPs50 %, and PSOPs-60 %) were successfully synthesized using a simple chemical process. This process utilized castor oil and elemental sulfur as primary raw materials. Subsequently, PSOPs-30 % and PSOPs-40 % were cured to form films (P-30 % and P-40 %) and coated urea (PSCUF-30 % and PSCUF-40 %). The synthesis process, mechanism, and physical and chemical properties of PSOPs revealed that the amount of sulfur involved in polymerization was not proportional to the initial amount of sulfur added. The structure and thermal stability of PSOPs were characterized using Fourier -transform infrared spectroscopy (FTIR), 1H nuclear magnetic resonance (1H NMR), and thermogravimetric analysis (TGA). Minor variations in crosslinking degree and sulfur content between P-30 % and P-40 % caused some differences in mechanical properties, shore hardness, water absorption, and water contact angles. TG-FTIR analysis of P-30 % and P-40 % indicated the generation of carbonyl sulfide throughout the process, predominantly in the early stage and very few in the later stage. The cumulative nitrogen release times for PSCUF-40 %-7.0 % and PSCUF-30 %-7.0 % were 50 and 60 days, respectively. In terms of degradability, whether in distilled water or NaOH solution with pH 8, the degradation rate of P-40 % was higher than that of P-30 %, reaching 6.55 % and 6.92 % over 70 days. In addition, methyl ricinoleic (MCO) was utilized as a polyol to prepare PCUF-MCO for comparative analysis.