本文選題：膜材料　切入點：聚乙烯醇　出處：《沈陽農(nóng)業(yè)大學》2015年碩士論文　論文類型：學位論文

【摘要】：養(yǎng)分控釋效果好、可降解的膜材料是當前包膜緩釋肥料領域研究的熱點問題之一。本文采用聚乙烯醇為主要原料,草酸、海藻酸鈉、殼聚糖、二氧化硅為改性劑,利用化學合成的方法研制了包膜緩釋肥料用的改性聚乙烯醇膜材料。通過對膜材料的吸水率、應力和伸縮率等指標的測定分析,明確膜材料的改性條件；利用傅里葉紅外光譜和掃描電鏡,闡明膜材料改性機理和降解性能。研究結(jié)果如下：(1)草酸、海藻酸鈉、殼聚糖三種改性劑均能使膜材料的應力降低,但并不存在明顯的差異；三種改性劑也均能使膜材料的伸縮率增大,其中海藻酸鈉改性劑的效果最佳；以吸水率為主要參考指標,草酸和殼聚糖為改性劑制備的改性聚乙烯醇膜材料,可以顯著降低其吸水率,并且工藝條件為聚乙烯醇濃度55g/kg,草酸濃度32g/kg,反應溫度90℃,反應時間2.5h時制備的草酸改性聚乙烯醇膜材料吸水率最低,最適合制備膜材料。(2)向改性聚乙烯醇中添加無機物二氧化硅之后,其吸水率進一步降低,特別是本身吸水率較高的處理,吸水率降低越明顯；應力和伸縮率也有降低的趨勢。(3)紅外光譜分析結(jié)果表明,膜材料經(jīng)過改性或添加二氧化硅之后,其主要吸收峰峰值大小和透射率發(fā)生明顯的變化,說明改性劑、二氧化硅均能與聚乙烯醇發(fā)生反應,得到了目標產(chǎn)物,并且使得膜材料的結(jié)構(gòu)和性能發(fā)生了變化。(4)通過質(zhì)量變化、紅外光譜和膜材料表面微觀結(jié)構(gòu)的分析,得到相同膜材料經(jīng)過不同的培養(yǎng)方式后,降解率不同；而在同一種培養(yǎng)方式下不同的改性膜材料的降解率也不同。其中降解率最大的是草酸改性聚乙烯醇膜材料,其值為37.8%。添加適量的二氧化硅可以提高殼聚糖改性膜的降解率,但是會降低草酸、海藻酸鈉改性膜的降解率�？傊�,聚乙烯醇通過草酸、海藻酸鈉、殼聚糖以及二氧化硅改性后性能發(fā)生了變化,在環(huán)境中的降解能力也增強,根據(jù)不同的要求,合理地控制工藝條件,可以用來制包膜材料。
[Abstract]:In this paper, polyvinyl alcohol was used as the main raw material, oxalic acid, sodium alginate, chitosan, silica as modifier. The modified polyvinyl alcohol membrane material for coated slow-release fertilizer was prepared by chemical synthesis. The modification conditions of membrane material were determined by measuring and analyzing the water absorption, stress and expansion rate of membrane material. Fourier transform infrared spectroscopy and scanning electron microscope were used to elucidate the modification mechanism and degradation performance of the membrane material. The results are as follows: 1) oxalic acid, sodium alginate and chitosan can reduce the stress of the membrane material, but there is no obvious difference. The three modifiers can also increase the expansion rate of membrane materials, among which the sodium alginate modifier is the best, and the modified polyvinyl alcohol membrane material prepared by oxalic acid and chitosan as the main reference index is the water absorption rate, and the modified polyvinyl alcohol membrane material is prepared with oxalic acid and chitosan as modifiers. The water absorptivity of the modified PVA membrane was decreased significantly under the conditions of 55 g / kg PVA concentration, 32 g / kg oxalic acid concentration, 90 鈩，

本文編號：1631786