DPSSL-microscopy of polymer compositions based on polyethylene [10803-020] and gas-generating agent hydrocerol

Compositions on the basis of polyethylene (PE) of grade 10803-020 (Russia) were investigated. The particulate chemical gas-generating agent hydrocerol (hyd) of Hydroserol BIF brand with the starting decomposition temperature of 140°C, which is the mix of endothermic foaming agents, including sodium hydrogen carbonate, was used for creating the pore structure. The gaseous products of hydrocerol degradation are water vapor and carbon dioxide in equal proportions. It is assumed that the formed gas is distributed in the polymer melt in the form of meshes; in this case the tear of walls, fusion of meshes and formation of pores may take place. The following substances was used as the natural particulate fillers: wood flour (WF) of three fractions with the size of the particles up to 80, 14 and 200 μm; corn starch (st) of Hi Maize 1043 brand with the particle size of 100 μm. The elemental chemical composition of the wood flour is approximately the same for all wood species, namely wt %: carbon – 49 – 51%, oxygen – 43 – 44%, hydrogen – 6,0 – 6,4%, nitrogen – 0,1 – 0,03%. The main materials composing the wood are natural polymers: cellulose, lignin, hemicellulose. Wood flour is the waste of the woodworking and timber industry.The fillers are finely dispersed. They increase the number of defects in the matrix and thereby decrease the robustness of material against physical and impacts.The PE compositions with hydrocerol were obtained by mechanical mixing in the melt on laboratory micro-roll mills VK-6 (Russia) with the heating at 120°C. This method provides a quite uniform distribution of the filler in the polymer melt. The hydrocerol content in the test charge and compositions was 5 wt %. Mixing was performed until a uniform distribution of the hydrocerol particles in the polymer melt was attained. Introduction of the natural component was also performed on the rotating roll mills until a uniform distribution of the particles in the polymer melt was attained. The natural component content in the compositions was 15 or 30 wt %. Formulations of the compositions are given in the table below:Table – Formulations of investigated compositions№Composition1PE (test charge)2PE + 5%hyd (test charge)3PE + 5%hyd+15%WF(0-80)4PE + 5%hyd + 15%WF(0-140)5PE + 5%hyd + 15%WF(0-200)6PE + 5%hyd + 15%st7PE + 5%hyd + 30%WF(0-80)8PE + 5%hyd + 30%WF(0-140)9PE + 5%hyd + 30%WF(0-200)10PE + 5%hyd + 30%st After mixing, the viscous mass was removed from the roll mills and cooled at room temperature (20±2°C) down to hardening. Samples in the form of round plates were obtained by pressing in the form of a hardened chopped mass on a manual laboratory hydraulic press at 120°C without pressure. At the same time foaming was performed at 160°C – the temperature of more complete decomposition of hydrocerol.

本研究针对俄罗斯10803-020等级聚乙烯（PE）的复合材料进行了探讨。采用Hydroserol BIF品牌的水解醇（hyd）作为粒状化学气体发生剂，其起始分解温度为140°C，该混合物包含吸热发泡剂，如碳酸氢钠，用于构建孔隙结构。水解醇降解产生的气体产品为水蒸气和二氧化碳，比例相等。假设生成的气体以网格状形式分布于聚合物熔体中；在这种情况下，可能发生熔体壁的撕裂、网格的融合以及孔隙的形成。以下物质被用作天然粒状填充剂：尺寸上限分别为80、14和200微米的木材粉末（WF）；Hi Maize 1043品牌玉米淀粉（st），粒径为100微米。木材粉末的元素化学组成对于所有树种大致相同，即质量百分比：碳-49%-51%，氧-43%-44%，氢-6.0%-6.4%，氮-0.1%-0.03%。木材的主要成分是天然聚合物：纤维素、木质素、半纤维素。木材粉末是木工和木材行业的废弃物。填充剂被精细分散，它们增加了基体中的缺陷数量，从而降低了材料对物理和冲击的韧性。含有水解醇的PE复合材料通过在实验室微型滚筒磨（VK-6，俄罗斯）的熔体中进行机械混合获得，混合温度为120°C。此方法确保了填充剂在聚合物熔体中的均匀分布。测试样品和复合材料的水解醇含量为5 wt %。混合直至水解醇粒子在聚合物熔体中均匀分布。天然成分的引入也是在旋转滚筒磨中进行的，直至粒子在聚合物熔体中均匀分布。复合材料的天然成分含量为15或30 wt %。表下给出了复合材料的配方：

表 – 调查复合物的配方

№ 复合物 1 PE（测试样品） 2 PE + 5%hyd（测试样品） 3 PE + 5%hyd + 15%WF(0-80) 4 PE + 5%hyd + 15%WF(0-140) 5 PE + 5%hyd + 15%WF(0-200) 6 PE + 5%hyd + 15%st 7 PE + 5%hyd + 30%WF(0-80) 8 PE + 5%hyd + 30%WF(0-140) 9 PE + 5%hyd + 30%WF(0-200) 10 PE + 5%hyd + 30%st

混合后，将粘稠物质从滚筒磨中取出，在室温（20±2°C）下冷却至硬化。通过在120°C的手动实验室液压机上对硬化切碎物料进行压制，获得了圆形板状的样品，压制过程中不施加压力。同时，在160°C的温度下进行发泡，这是水解醇更完全分解的温度。