Infrared Spectrum Studies of Coatings under Irradiation of Sunlight and Ultraviolet
LI Li-xia1, 2, CAO Bing1, 2*, SUN Yu-meng1, 3, LI Hong-yan1, 2, XIAO Qiang1, 2, NI Xiao-hui1, 2, YI Wen-ping1, 2
1. Institute of Plant Nutrition and Resource, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China 2. Research Center of Beijing Municipal Slow and Controlled Release Fertilizers Engineering Technology, Beijing 100097, China 3. College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China
Abstract：Degradable resin- coated controlled release fertilizer is one of the hottest current research focuses in the field of fertilizer. In terms of practical application, the photodegradability characteristics of three kinds of coatings including polyethylene/hydrophilic nano-TiO2 composite, polyethylene/hydrophilic nano-TiO2 composite and pure polyethylene were analyzed under irradiation of sunlight and ultraviolet by ATR-FTIR, which was aimed to know their degradation behaviors under two conditions. The result showed that under irradiation of sunlight and ultraviolet, the type of functional group was not changed with the addition of the photo-catalyst, but the photo-catalyst just had an effect on intensity of functional groups. The trend was polyethylene/hydrophobic nano-TiO2 composite>polyethylene/hydrophilic nano-TiO2 composite>pure polyethylene. Furthermore, sunlight and ultraviolet had different effects on molecular structures of coatings. Under irradiation of sunlight, crosslinking reaction took place and ether bond was generated among the carbon chain of polyethylene except for the form of hydroperoxides. Then, carbon chain continued being oxidized to form carbonyl group. The existence of carbonyl group promoted the further degradation of coatings; under irradiation of ultraviolet, high local concentrations of reactive oxygen species were produced and the ability to attack the carbon chain of polymer was strong. Thus, the long alkyl chain of polyethylene was quickly oxidized to form intermediate products containing carbonyl groups. However, the irradiation experiment of ultraviolet didn’t fully reveal the degradation behavior of coatings.
[1] Azeem B, KuShaari K, Man Z B, et al. Journal of Controlled Release, 2014, 181(1): 11. [2] Pereira E I, da Cruz C C T, Solomon A, et al. Industrial & Engineering Chemistry Research, 2015, 54(14): 3717. [3] Hayatsu M. Microbes and Environments, 2014, 29(2): 121. [4] Chalk P M, Craswell E T, Polidoro J C, et al. Nutrient Cycling in Agroecosystems, 2015, 102(2): 167. [5] Shibata M, Konno T, Akaike R, et al. Plant and Soil, 2007, 290(1-2): 201. [6] Yang Y C, Zhang M, Li Y C, et al. Journal of Agricultural and Food Chemistry, 2012, 60(45): 11229. [7] LI Ya-xing, XU Qiu-ming, YANG Yi-bin, et al(李亚星，徐秋明，杨宜斌，等). Ecology and Environmental Sciences(生态环境学报), 2010, 19(7): 1691. [8] LI Li-xia, CAO Bing, LI Hong-yan, et al(李丽霞，曹 兵，李鸿雁，等). Acta Materiae Compositea Senica(复合材料学报), 2014, 31(6): 1422. [9] ZHANG Chuan-chao, ZHANG Li-juan, LIAO Wei, et al(张传超，张丽娟，廖 威，等). Chinese Physics B(中国物理B), 2015, 24(2): 024220. [10] Benítez A, Sánchez J J, Arnal M L, et al. Polymer Degradation and Stability, 2013, 98(2): 490. [11] Ohtani B, Adzuma S, Nishimoto S, et al. Polymer Degradation and Stability, 1992, 35(1): 53. [12] Dong W, Gijsman P. Polymer Degradation and Stability, 2010, 95(6): 955.
