The effect of UV irradiation on the structure and properties of linear low-density polyethylene (LLDPE) and the mechanical properties of nylon 66 (PA66)/LLDPE blends were studied with FTIR and XPS, measurements of gel...The effect of UV irradiation on the structure and properties of linear low-density polyethylene (LLDPE) and the mechanical properties of nylon 66 (PA66)/LLDPE blends were studied with FTIR and XPS, measurements of gel, melt index, and water contact angle, and mechanical property tests. The results show that oxygen-containing groups such as C-O, C=O and C (=O) O were introduced onto molecular chains of LLDPE by the UV irradiation in air without adding any additives. The content of these groups increased with irradiation time. Gel formation was found in LLDPE after 12 h UV irradiation, and the gel fraction increased with the irradiation time. Melt index and water contact angle of the irradiated LLDPE decreased. Due to the introduction of the oxygen-containing groups, interfacial interactions between PA66 and the irradiated LLDPE increased. Therefore mechanical properties of PA66/irradiated LLDPE blends were improved compared with PA66/LLDPE blend. Tensile strength and notch impact strength of the PA66/irradiated LLDPE blends increased with irradiation time.展开更多
以线性低密度聚乙烯（linear low density polyethylene,LLDPE）为基础树脂,采用紫外光交联法制备了交联聚乙烯试样（记为XLPE1）,并利用水刀电极法比较了XLPE1与过氧化物交联低密度聚乙烯（记为XLPE2）在抗水树性能的差异。结果表明,...以线性低密度聚乙烯（linear low density polyethylene,LLDPE）为基础树脂,采用紫外光交联法制备了交联聚乙烯试样（记为XLPE1）,并利用水刀电极法比较了XLPE1与过氧化物交联低密度聚乙烯（记为XLPE2）在抗水树性能的差异。结果表明,未经过交联反应的LLDPE的水树枝尺寸明显低于低密度聚乙烯（linear low density polyethylene,LDPE）,即使两种材料在经过交联反应后抗水树能力均变强,但XLPE1的抗水树性能仍优于XLPE2。拉伸实验过程中出现的应变硬化现象表明,交联键以及LLDPE中密集的短支链均可以增加无定形相的连接分子链密度,延缓了水树的生长。另外,动态热机械分析（dynamic mechanical analysis,DMA）结果表明交联反应使材料无定形相韧性增加,有助于吸收微水珠的冲击力。XLPE1具有相对优异的抑制水树生长能力,这可能与LLDPE抗水树性能略好以及其交联度略高有关。展开更多
The oxygen-contained groups such as C—O,C—OH,CO,C(O)O and C(O)OH are introduced onto the molecular chains of linear low density polyethylene(LLDPE) through ultraviolet irradiation at environmental temperature of 70 ...The oxygen-contained groups such as C—O,C—OH,CO,C(O)O and C(O)OH are introduced onto the molecular chains of linear low density polyethylene(LLDPE) through ultraviolet irradiation at environmental temperature of 70 ℃ in air without adding any additives.The concentration of these groups increases with the iucrease of irradiation time.The gel appears in irradiated LLDPE,the gel content increases with the iucrease of irradiation time.The melt flow index decreases and reach minimum when the irradiation time is 24 h,and then increase.The interfacial adhesion between irradiated LLDPE and polyamide 66(PA66) and the mechanical properties of the PA66/irradiated LLDPE(80/20) blends are improved owing to the oxygen-contained polar groups introduced.Compared with those of PA66/LLDPE(80/20) blends,the tensile strength,Young′s modulus,bending strength and notch impact strength of PA66/irradiated LLDPE(80/20) blends for 24 h are increased from 48.3,908,64.8 MPa and 31 J/m\ to 62.0,984,83.1 MPa and 85 J/m,respectively.展开更多
文摘The effect of UV irradiation on the structure and properties of linear low-density polyethylene (LLDPE) and the mechanical properties of nylon 66 (PA66)/LLDPE blends were studied with FTIR and XPS, measurements of gel, melt index, and water contact angle, and mechanical property tests. The results show that oxygen-containing groups such as C-O, C=O and C (=O) O were introduced onto molecular chains of LLDPE by the UV irradiation in air without adding any additives. The content of these groups increased with irradiation time. Gel formation was found in LLDPE after 12 h UV irradiation, and the gel fraction increased with the irradiation time. Melt index and water contact angle of the irradiated LLDPE decreased. Due to the introduction of the oxygen-containing groups, interfacial interactions between PA66 and the irradiated LLDPE increased. Therefore mechanical properties of PA66/irradiated LLDPE blends were improved compared with PA66/LLDPE blend. Tensile strength and notch impact strength of the PA66/irradiated LLDPE blends increased with irradiation time.
文摘以线性低密度聚乙烯（linear low density polyethylene,LLDPE）为基础树脂,采用紫外光交联法制备了交联聚乙烯试样（记为XLPE1）,并利用水刀电极法比较了XLPE1与过氧化物交联低密度聚乙烯（记为XLPE2）在抗水树性能的差异。结果表明,未经过交联反应的LLDPE的水树枝尺寸明显低于低密度聚乙烯（linear low density polyethylene,LDPE）,即使两种材料在经过交联反应后抗水树能力均变强,但XLPE1的抗水树性能仍优于XLPE2。拉伸实验过程中出现的应变硬化现象表明,交联键以及LLDPE中密集的短支链均可以增加无定形相的连接分子链密度,延缓了水树的生长。另外,动态热机械分析（dynamic mechanical analysis,DMA）结果表明交联反应使材料无定形相韧性增加,有助于吸收微水珠的冲击力。XLPE1具有相对优异的抑制水树生长能力,这可能与LLDPE抗水树性能略好以及其交联度略高有关。
文摘The oxygen-contained groups such as C—O,C—OH,CO,C(O)O and C(O)OH are introduced onto the molecular chains of linear low density polyethylene(LLDPE) through ultraviolet irradiation at environmental temperature of 70 ℃ in air without adding any additives.The concentration of these groups increases with the iucrease of irradiation time.The gel appears in irradiated LLDPE,the gel content increases with the iucrease of irradiation time.The melt flow index decreases and reach minimum when the irradiation time is 24 h,and then increase.The interfacial adhesion between irradiated LLDPE and polyamide 66(PA66) and the mechanical properties of the PA66/irradiated LLDPE(80/20) blends are improved owing to the oxygen-contained polar groups introduced.Compared with those of PA66/LLDPE(80/20) blends,the tensile strength,Young′s modulus,bending strength and notch impact strength of PA66/irradiated LLDPE(80/20) blends for 24 h are increased from 48.3,908,64.8 MPa and 31 J/m\ to 62.0,984,83.1 MPa and 85 J/m,respectively.
