为了解决周期性爆发的巢湖水华蓝藻难以处置的问题, 同时改善低密度聚乙烯材料降解周期长的现状, 以低密度聚乙烯(LDPE)为基体, 以巢湖新鲜水华蓝藻制得的蓝藻粉为生物材料, 以马来酸酐接枝聚乙烯 (PE-g-MAH)为增容剂, 以聚乙烯蜡和白油为润滑剂制备复合材料。 设置蓝藻粉含量和增容剂含量2个因素作为实验因素, 实验材料按一定比例充分混合后, 双螺杆挤出制得了复合材料颗粒, 再经过注塑方式获得待测样条。 通过紫外-可见光谱扫描(UV-VIS)联合傅里叶变换红外光谱扫描(FTIR)的光谱学方法了解水华蓝藻粉、 增容剂和复合材料的光谱学特征, 分析复合材料制备过程中的结构变化, 能够先决性判断该种实验方法对制备新型生物材料的可行性。 并以力学性能测试和扫描电镜(SEM)等方法作为辅助手段, 与光谱分析的结果相互反馈, 充分分析水华蓝藻粉、 增容剂含量对复合材料结构与性能的影响。 结果显示: 通过紫外可见光谱分析, 蓝藻初提液在260和620 nm处出现藻蛋白质的特征吸收峰, 表明了蓝藻细胞液中藻蛋白的存在, 具备作为生物反应材料的基本条件。 红外光谱分析可知, 蓝藻粉在1 630, 1 540和1 440 cm^-1附近出现特征吸收峰, 符合酰胺键的出峰规律, 在3 300 cm^-1附近出现O—H的特征吸收峰, 进一步验证了蓝藻粉活性位点的存在; 马来酸酐的红外光谱图中, 酸酐在1 850和1 740 cm^-1处出现C=O基的特征峰, 环状酸酐中C—O—C的伸缩振动特征峰出现在1 200 cm^-1附近; 而经过反应所得的复合材料红外光谱中, 除聚乙烯的特征吸收峰以外, 蓝藻粉中的酰胺键和O—H, 以及马来酸酐对应得特征吸收峰都已减弱或消失了, 基本可以推测马来酸酐与—OH发生了开环酯化反应, 马来酸酐在生物复合材料的制备过程中起到了连接两个不同反应体系的作用。 而且, 通过扫描电镜可直观的看出, 蓝藻粉含量增加将会导致复合体系中成团现象加剧, 增容剂的加入增强了复合体系界面的粘结性; 力学性能测试的结果为蓝藻粉含量的增加导致复合材料力学性能下降, 尤其冲击性能下降显著降幅达54.10%; 当蓝藻粉的添加量为15.00%时, 随着增容剂用量的增加, 材料的拉伸强度、 弯曲性能和冲击性能均呈现先增大后减小的趋势。 扫描电镜和力学性能的结果也从侧面验证了光谱分析结果的前瞻性和正确性, 避免了盲目实验带来的资源浪费等问题。 综合考虑, 该生物复合材料可选取蓝藻粉含量15.00%, 增容剂含量3.00%, 聚乙烯蜡和白油用量3.00%和1.00%的配方, 此时的力学性能为: 拉伸强度为11.70 MPa, 冲击强度为20.00 kJ·m^-2, 弯曲强度为8.80 MPa, 弯曲模量为220.00 MPa。

The project was started in order to solve the problem of periodic outbreaks of cyanobacteria in Chaohu Lake, and to improve the state of long degradation cycle of low-density polyethylene materials. In this study, the low density polyethylene (LDPE) was taken as matric, and algae powder was taken as bio-material. Maleic anhydride grafted polyethylene (PE-g-MAH) was used as compatibilizer, and polyethylene wax and white oil were used as lubricant. The dosages of compatibilizer and algae powder were selected as the two factors in this paper. Mix the experimental materials in a certain proportion, then prepare the composite particles by double-screw extrusion method, obtain the samples by injection. By using ultraviolet-visible spectroscopy (UV-Vis) and fourier transform infrared spectrometer (FTIR Spectrometer), we can learn the spectral characteristics of materials, and analyze the structural changes of composite materials in the preparation, thus we can determine whether this method is feasible in preparing this composite in advance. Meanwhile, by using mechanical performance testing and scanning electron microscopy (SEM) as auxiliary means, comparing with the results of spectral analysis, we can adequately analyze the effects of algae powder and compatibilizer content on the structure and properties of the composite. Results showed that the absorption peaks appeared at 260nm and 620nm when using ultraviolet-visible absorption spectroscopy to analyze the separated liquid components obtained from the algae. It is proved that the algae contains phycobiliprotein and can be used as the bio-material in the preparation of composite materials. The characteristic peaks of amido bond has appeared respectively at 1 630, 1 540 and 1 440 cm^-1 when using fourier transform infrared spectrometer to analyze the substances that participate in the reaction, which was in line with the peak law of amide bond; and the characteristic absorption peaks of O—H appeared near 3 300 cm^-1, which can further verify the existence of the active site of algae powder. It can be seen in the infrared spectrum of maleic anhydride, the characteristic peaks of C=O group appeared at 1 850 and 1 740 cm^-1, and the characteristic peak of stretching vibration of C—O—C in cyclic anhydride appeared around 1 200 cm^-1. However, the characteristic peaks of amide bonds, H—O group and maleic anhydride except the characteristic absorption peak of polyethylene were weakened or disappeared when using Fourier transform infrared spectrometer to analyze the composite material obtained by reaction, and it can be speculated that the maleic anhydride has an open-loop esterification reaction with —OH, and the maleic anhydride plays a role in connecting two different reaction systems in the preparation of biological composites. In addition, it can be investigated intuitively by using scanning electron microscopy that the increase of algae powder content will lead to the aggravation of clumping in the composite system, and the addition of compatibilizer enhanced the adhesion of the interface of the composite system. The mechanical property test showed that the mechanical properties decreased with the increase of algae powder content, especially the decrease of impact properties with 54.10%. Results showed that when 15.00% of algae powder was added in the composite, the tensile strength, flexural property and impact property of the composite first increase and then decrease with increasing of compatibilizer content. Therefore, the results of scanning electron microscopy and mechanical properties verify the foresight and correctness of spectral analysis results from the side, avoiding the waste of resources caused by blind experiments and other issue. The optimized conditions for preparation of the bio-composite were determined with 15.00% of algae powder, 3.00% of PE-g-MAH, 3.00% of polyethylene wax and 1.00% of white oil. The mechanical properties of the bio-composite prepared under this condition were 11.70 MPa of tensile strength, 20.00 kJ·m^-2 of impact strength, 8.80 MPa of bending strength, and the bending modulus was 220.00 MPa.