乙基纤维素-乙酸甲酯薄膜的制备、降解及成膜机理研究

本实验以乙基纤维素为原料，制备了三种不同浓度的乙基纤维素-乙酸甲酯（ECA）薄膜。首先，将0.2 g、0.4 g、0.6 g的乙基纤维素样品分别加入到一个容量为25 ml的烧杯中，并加入10 ml乙醇溶液。在40℃的水浴中加热搅拌，直至完全溶解。此时，得到了三种不同浓度（分别为0.02 g/ml、0.04 g/ml、0.06 g/ml）的乙基纤维素溶液。随后，将这些溶液均匀地倒在玻璃板上，并使用1000 μm的刮膜刀从上至下刮平。将样品风干半小时，即可得到三组乙基纤维素-乙酸甲酯薄膜。

接下来，使用傅立叶红外光谱仪，结合实验现象和相关文献，推测ECA膜的成膜机理。

为了研究ECA薄膜的生物降解特性，将一定质量的三组薄膜样品埋在深度为3 cm - 5 cm的土壤中，并设置3个平行实验。隔一段时间取出样品，洗净并烘干，测定薄膜的质量，通过薄膜质量的变化初步判断薄膜是否可以被生物降解。同时，利用红外光谱图来判断降解过程中是否产生了新的物质。此外，使用扫描电镜观察薄膜表面的微观结构，以了解薄膜的降解情况。

In this experiment, three different amounts of ethyl cellulose samples (0.2 g, 0.4 g, and 0.6 g) were added to a 25 ml beaker along with 10 ml of ethanol solution. The mixture was heated and stirred in a 40℃ water bath until completely dissolved, resulting in three different concentrations (0.02 g/ml, 0.04 g/ml, and 0.06 g/ml) of ethyl cellulose solution. The solutions were then evenly poured onto a glass plate and scraped flat using a 1000 μm scraper. After air-drying for half an hour, three groups of ethyl cellulose-acetone methyl ester films were obtained.

Fourier-transform infrared spectrometry was used to speculate the film-forming mechanism of ECA films based on experimental phenomena and relevant literature.

Furthermore, a certain amount of each group of film samples was buried in soil with a depth of 3 cm - 5 cm, and three parallel experiments were conducted. The samples were taken out at regular intervals, washed, and dried to measure the film's weight, which was used to preliminarily determine whether the film could be biodegraded. In addition, the infrared spectra were used to identify whether any new substances were produced during the degradation process. Moreover, scanning electron microscopy was used to observe the microstructure of the film surface and to understand the degradation of the film.