二氧化硅/聚乙二醇/VAE乳液复合包膜缓释肥的制备及性能

以湿法磷酸脱氟制备氟化钾时的副产物二氧化硅,聚乙二醇,VAE乳液,丙三醇和磷酸铝为主要原料,以水为溶剂制成包膜乳液,采用多次雾化喷涂的方式对磷酸二铵颗粒肥料进行喷涂,制备了包膜缓释肥。研究了包覆率和二氧化硅加入量对其缓释性能的影响以及产品在土壤中的保水性能;并通过扫描电镜观察了包膜后肥料表面和剖面的形貌特征。结果表明:当包覆率达到40%时,产品的初期养分释放率小于15%,28天累积养分释放率小于80%,达到了缓释肥料国家标准GB/T 23348-2009的要求;产品在土壤中可以提高土壤的最大持水率和保水性能,对水资源利用率的提高具有重要意义,同时包膜材料还具有可生物降解、无环境污染等优点。     

聚氨酯缓/控释肥制备与膜层表征

利用多亚甲基多苯基异氰酸酯与蓖麻油在尿素表面反应成膜,制备了聚氨酯包覆的尿素缓/控释肥,通过红外光谱和扫描电镜研究了聚氨酯包覆量对膜层结构的影响,采用凯氏定氮法测定了尿素的溶出曲线。结果表明,不同包膜量聚氨酯膜层的反应程度存在差异;随着包膜量的增加,膜层的厚度增加;当聚氨酯的包覆质量分数为3.3%时,25℃下尿素的缓释期达到40～50 d;根据尿素的溶出曲线推测该缓/控释肥的释放为扩散机制。     

聚氨酯包膜控释尿素制备工艺与养分释放特性研究

4,4'-二苯基甲烷二异氰酸酯(MDI)与植物油多元醇均匀喷涂在流化状态的尿素颗粒表面并发生化学反应,形成聚氨酯膜层。以侧喷流化床包膜工艺为基础,通过研究包膜量、反应温度、反应物比例等不同工艺条件下包膜尿素的养分释放性能,获得的生产聚氨酯包膜尿素的最佳工艺条件为反应温度75℃、MDI与植物油质量比1.0:1.0、反应时间20 min、催化剂用量0.40%(质量分数)、包膜比率为4.0%(质量分数),此包膜控释尿素的养分释放周期可达70 d。     

具有吸水保水功能的改性魔芋共聚物包膜缓释尿素的制备及其性能研究

以烯丙基硫脲改性魔芋葡甘聚糖为包膜剂制备包膜缓释尿素。对包膜缓释材料进行扫描电子显微镜(SEM)表征,并分析其吸水性能;评价温度及土壤水含量对包膜缓释尿素氮素溶出率的影响,利用土柱淋溶法检测包膜缓释尿素的缓释效果,并分析缓释尿素对白菜的生长影响。结果表明,烯丙基硫脲接枝魔芋葡甘聚糖在接枝率为35%~45%时,吸水性能最好,吸水量高达794 g/g;随着温度和土壤水含量的升高,包膜缓释尿素氮素溶出率逐渐增加;氮素溶出具有典型的缓释肥溶出特征,表现出良好的缓释效果;白菜对缓释尿素中氮素的利用率提高。     

聚酯/聚醚型聚氨酯互换膜材的制备与应用

为了优化聚氨酯(PUR)包膜尿素控释性能,采用多亚甲基多苯基异氰酸酯分别与聚酯和聚醚多元醇按不同配比混合,依照不同次序先后喷涂在尿素颗粒表面制备聚酯型和聚醚型PUR互换层包膜尿素并利用分光光度法研究其控释性能。通过接触角、热重分析和扫描电子显微镜对膜材的润湿性、热稳定性和形貌进行了表征,并采用傅立叶变换红外光谱分析了尿素释放过程中膜层的结构变化。结果表明,聚酯型PUR的疏水性弱于聚醚型PUR,但热稳定性高于后者;两者的包覆次序影响PUR包膜尿素的控释效果,聚酯型PUR为外层、聚醚型PUR为内层时控释性能优良,当两者包覆比例(质量比)为1.5∶1.5时,释放期最长可达84 d。     

腰果酚醛树脂包膜尿素的制备及缓释性能

用腰果酚醛树脂作为包膜材料制备了一系列不同膜厚的包膜尿素。并采用水浸泡溶解法、淋溶法、土壤法评价所得包膜尿素的缓释特性。结果表明,利用腰果酚醛树脂包膜后的尿素具有明显的缓释性能,包覆量为26.3%的单层包膜尿素30 min后溶解率为50%,而包覆量为82.6%的双层包膜尿素113 h后溶出率为83.16%,双层包膜尿素的缓释性能明显好于单层包膜尿素。     

松香包膜尿素的释放特性研究

以松香为成膜物质,制备了一系列的包膜尿素,利用扫描电子显微镜研究了包膜尿素的表面形貌,用浸泡溶解法表征了所得包膜尿素的释放特性,讨论了包覆量与操作条件对包膜尿素释放特性的影响。结果表明,松香是一种优良的尿素包膜材料,包覆量在5%以上时,松香包膜尿素具有显著缓释性能,包覆量越大,缓释效果越好。     

不同包膜缓释肥料对夏玉米生长和产量影响的研究分析

通过田间试验,探讨了不同包膜形式的缓控释肥与普通复合肥对夏玉米生长指标及产量指标的影响。结果表明,缓控释肥较普通复合肥对夏玉米生长效果更好,而且不同包膜形式肥料对夏玉米产量影响程度不同,特别是全降解缓释肥26-8-8复合肥料增产效果最明显,较普通复合肥处理产量提高了14.18%。为缓控释肥在夏玉米上合理施用提供了依据和技术指导。     

非焦油型双组分聚氨酯防水涂料的研制

通过一定比例合成含有NCO的聚氨酯预聚体为A组分,将粉料、聚醚、MOCA、助剂等制成B组分,将A、B组分按质量比1∶2混合成膜制得非焦油型双组分聚氨酯涂料。探讨了NCO含量、MOCA、催化助剂、消泡剂对双组分聚氨酯涂料的影响,结果表明:NCO含量在4.0%~4.6%、MOCA含量在2.5%~4.0%、催化剂在0.08%~0.12%、消泡剂在0.3%~0.7%,可以制得性能优异的双组分聚氨酯涂料。     

磷酸铝包覆氧化铁黄颜料的制备及其耐温性能研究

氧化铁黄颜料受热易脱水变色,限制了其在温度较高环境下的应用。提高氧化铁黄的热稳定性具有很重要的意义。通过液相水解沉积的方法对氧化铁黄表面进行磷酸铝表面包覆,研究了磷酸铝包膜的工艺条件（pH、包膜量、温度）对氧化铁黄包覆的表面形貌和微观结构的影响。结果表明：在pH为7、磷酸铝的包膜量为13%、包覆温度为65 ℃时,在氧化铁黄表面的包覆效果最佳。采用色差法研究了在最佳条件下进行磷酸铝包覆的氧化铁黄颜料,结果表明其耐温性得到显著提高。     

可生物降解PBS包膜尿素缓释肥料的制备与性能研究

研究可生物降解PBS包膜尿素缓释肥料的制备与性能。以可生物降解PBS为包膜材料,通过循环流化床工艺制备PBS包膜尿素缓释肥料,经过对制备工艺进行优化,确定包膜剂PBS质量分数为5%、二次流化时间为20 min、包膜率为10%的PBS包膜尿素具有良好的缓释效果,其初期释放率为10%,第28天时累积释放率为72%,基本符合缓释肥料标准。     

腐植酸涂层BB肥在水稻高产栽培中的应用

水稻腐植酸涂层BB肥的缓释机理是膜反应与团絮结构;涂层材料是营养物质,特别是配置了硅、锌等营养成分,有显著的增产提质、增强抗性效能;技术经济性好,比同类复合肥单位纯养分价格仅高3.7%～3.9%,是中国农民用得起的大田作物缓释肥料。     

缓释肥料的开发

缓释肥料的开发途径有:①通过化学反应合成缓释肥料,如脲醛缩合物;②对化肥进行包膜,制成包膜肥料;③掺入阻硝化剂或脲酶抑制剂制成缓释肥。其在土壤中的溶解速度慢,硝化分解时间长,养分利用率高,是环保节能产品。     

Properties of Coated Controlled Release Diammonium Phosphate Fertilizers Prepared with the Use of Bio-based Amino Oil

In an effort to enhance the efficiency of fertilizer use and minimize their negative impact on the environment, a novel biomass-based, functional controlled-release fertilizer was used to improve nutrient use efficiency and increase crop production systems for more sustainable agriculture practices. Here, bio-based amino-oil (Priamine) mixtures were proposed as an outer coating with different layers for the control of phosphorus release from diammonium Phosphate (DAP). These hydrophobic coatings conferred excellent barrier properties and flexibility to coatings. The morphological characterization of the coated fertilizer was performed by scanning electronic microscopy (SEM), electronic diffraction X-ray (EDX) and mapping, and revealed the formation of a cohesive film and a good adhesion between DAP fertilizer and coating film. The release rate of nutrients (phosphate) in water was investigated by UV–Vis spectrophotometer. The effect of coating thickness was investigated on release time and diffusion coefficient of phosphor release in distilled water. Release time increased with the coating thickness. The diffusion coefficient of nutrient release decreased with the coating thickness. Compared with uncoated granule which is totally solubilized after less than 2 hours, the P release profiles of the coated granules reached the equilibrium stage approximately after 98 and 126 hours when the DAP is coated with only Priamine single-layer (1L) and double-layer (2L), respectively. Moreover, the strategy adopted has successfully provided a very slow release and long-term availability of nutrient sources with bio-based coating oil compared to uncoated fertilizer (DAP) and therefore exhibited promising application for sustainable development of modern agriculture and circular economic.     

Application of waterborne acrylic emulsions in coated controlled release fertilizer using reacted layer technology

Waterborne acrylic emulsions modified with organic siloxanes and aziridine crosslinker were synthesized and applied as coating of controlled release fertilizer. The free films were characterized and th...     

羧甲基纤维素接枝丙烯酸/丙烯酰胺缓释肥包膜材料的制备、性能及应用

以过硫酸钾为引发剂、N,N′-亚甲基双丙烯酰胺为交联剂,采用水溶液聚合法制备了羧甲基纤维素接枝丙烯酸/丙烯酰胺缓释肥包膜材料,对其吸水性及耐盐性进行了检测,并将其应用于包膜尿素缓释肥的制备。结果表明,在羧甲基纤维素与丙烯酸质量比为3∶17、丙烯酰胺用量为12%时,所制备包膜材料在去离子水、自来水和0.4%盐水中的吸水率分别达到743g·g-1、497g·g-1和329g·g-1;包膜尿素缓释肥的氮素释放率满足GB/T 23348-2009要求,缓释周期达63d。     

Corrosion and wear behavior of alumina‐polyester nanocomposite coatings

The corrosion and wear behavior of powder coatings fabricated by the electrostatic method was investigated in this study. Pure polyester coating and fabricated nanocomposite powder coating with 10 and 20 mass.% alumina nanoparticles were coated with electrostatic spraying method on the surfaces of carbon steel substrate. Coatings were cured in two regimes by oven and microwave for the appropriate time. The effects of alumina nanoparticles on the corrosion resistance of coated samples were studied by immersion and electrochemical impedance spectroscopy (EIS) tests. Also, pin‐on‐disk test was applied to evaluate the wear properties and coefficient of friction (COF) of the coatings. The results of the corrosion test reveal that the samples with 10 mass.% alumina show the best corrosion resistance and cause a reduction in corrosion rates which is about 36 times to that of the pure sample. The wear rate of nanocomposite coatings is 10 times lower than that of pure ones and also the coefficient of friction of nanocomposite samples is almost half of the pure samples. Furthermore, the nanocomposite coatings cured in the microwave show better protection properties and wear resistance than that of ones cured in an oven. POLYM. ENG. SCI., 57:846–856, 2017. © 2016 Society of Plastics Engineers