【摘要】：世界人口數(shù)量的劇烈增長(zhǎng)使得對(duì)糧食的需求加大,大量使用化肥以提高糧食產(chǎn)量成為人們的選擇之一。然而傳統(tǒng)化肥利用率低,肥料的過(guò)度使用對(duì)環(huán)境產(chǎn)生較大危害,為解決這些問(wèn)題,急需開(kāi)發(fā)出新型肥料,緩控釋肥是其中的研究熱點(diǎn)。聚合物包膜型緩控釋肥的緩控釋效果同聚合物的結(jié)構(gòu)息息相關(guān),本論文主要從包膜聚合物的結(jié)晶度、親疏水性、鏈柔順性這三方面出發(fā),研究了其對(duì)尿素緩釋性能的影響。本論文的主要內(nèi)容有：(1)研究了結(jié)晶度對(duì)尿素緩釋性能的影響：以聚乳酸為研究對(duì)象,采用不同的方法成膜,發(fā)現(xiàn)以200目尼龍濾布為支撐流延制得的膜無(wú)明顯孔洞,形貌較好。通過(guò)控制熱處理的時(shí)間與溫度,得到了具有不同結(jié)晶度的聚乳酸膜。采用自制肥料釋放測(cè)定裝置測(cè)定尿素通過(guò)不同結(jié)晶度膜的釋放情況,發(fā)現(xiàn)結(jié)晶度越大,尿素累積釋放率越小。將尿素累積釋放率曲線進(jìn)行擬合,得到形同Qw=a*tb+6.64334×t0.79776的方程,擬合后得到與結(jié)晶度X相關(guān)的a、b值；再以X為橫坐標(biāo),分別以a、b為縱坐標(biāo),繪制曲線圖,將曲線進(jìn)行擬合,得到a、b與X的關(guān)系式分別為a=-0.07148X一3.30037:b=1.71998*10-4X3-0.01382X2+ 0.38051X-3.05255.(2)研究了親疏水性對(duì)尿素緩釋性能的影響：以甲基丙烯酸正丁酯為主要單體,引入不同含量的羥基與羧基,聚合后制備成膜,尿素緩釋實(shí)驗(yàn)結(jié)果表明,羥基和羧基的引入均使尿素累積釋放率變大；當(dāng)羥基與羧基含量相同時(shí),羧基的引入更有利于尿素的釋放；同一基團(tuán)的含量越大,尿素累積釋放率越大；聚合物膜親水性的增加有利于尿素的釋放。改變聚合物的親疏水性可以達(dá)到不同的緩釋效果。(3)研究了鏈柔順性對(duì)尿素緩釋性能的影響：合成了帶不同含量的羥基、羧基、酯基、苯環(huán)等的丙烯酸酯類聚合物,側(cè)基的不同使聚合物具有不同的鏈柔順性。實(shí)驗(yàn)結(jié)果表明,丙烯酸酯類聚合物的側(cè)基越長(zhǎng),尿素累積釋放率越大；側(cè)基體積越大,尿素累積釋放率越小；相對(duì)于單取代,對(duì)位非對(duì)稱取代不利于尿素的釋放；聚合物鏈柔順性越好,尿素累積釋放率越大。改變聚合物的柔順性可以控制尿素的釋放速率。
[Abstract]:With the rapid growth of the world population, the demand for food has increased, and the use of chemical fertilizers to increase grain production has become one of the choices. However, the utilization rate of traditional chemical fertilizer is low and the overuse of fertilizer is harmful to the environment. In order to solve these problems, it is urgent to develop a new type of fertilizer, and slow and controlled release fertilizer is one of the research hotspots. The sustained and controlled release effect of polymer coated slow release fertilizer is closely related to the structure of polymer. In this paper, the effect of polymer coated slow release fertilizer on urea sustained release performance was studied from three aspects: crystallinity, hydrophilicity and chain compliance of coated polymer. The main contents of this paper are as follows: (1) the effect of crystallinity on the sustained release properties of urea was studied: taking polylactic acid as the research object, the films were formed by different methods, and it was found that there were no obvious pores in the films prepared with 200 mesh nylon filter cloth as the support. The morphology is good. Polylactic acid films with different crystallinity were obtained by controlling the time and temperature of heat treatment. The release of urea through different crystallization films was measured by a self-made fertilizer release measuring device. It was found that the greater the crystallization degree was, the smaller the cumulative release rate of urea was. The cumulative release rate curve of urea was fitted, and the equation of Qw=a*tb 6.64334 脳 t 0.79776 was obtained, and the a and b values related to crystallization X were obtained after fitting. Then take X as the horizontal coordinate, take a, b as the longitudinal coordinate, draw the curve diagram, fit the curve, get a, The relationship between b and X is a 鈮，

本文編號(hào)：2494565