乙烯咔唑接枝聚乙烯的空间电荷特性及力学性能

Space Charge Characteristics and Mechanical Properties of Vinyl Carbazole Grafted Polyethylene

为了研究聚乙烯材料的空间电荷特性及力学性能,采用熔融法制备乙烯咔唑(VK)接枝聚乙烯(VK-g-LDPE),并通过电声脉冲法、差热扫描量热法和拉伸试验对VK-g-LDPE的空间电荷分布、结晶度和拉伸性能进行了测试。结果表明,随着接枝率的增加,对VK-g-LDPE内部空间电荷的抑制效果呈现先增强后减弱的趋势;当接枝率为12.45%时,对VK-gLDPE材料空间电荷的抑制作用最好,试样的电荷密度最大值仅为0.31 C/m^3,比聚乙烯降低了95.87%;随着接枝率的增加,VK-g-LDPE的结晶度呈下降趋势;随着接枝率的增加,VK-g-LDPE的拉伸强度呈现先增大后降低的趋势,且当接枝率为13.02%时达到最大值14.2 N/mm^2;随着接枝率的增加,VK-g-LDPE的断裂伸长率和弹性模量呈现下降的趋势。

In order to study the space charge and mechanical properties of the polyethylene-based materials, vinyl carbazole （VK） grafted polyethylene （VK-g-LDPE） were prepared by melting method. The space charge distribution, crystallinity and mechanical properties of the vinyl carbazole grafted polyethylene were investigated through pulsed electro-acoustic （PEA）, differential thermal scanning calorimetry （DSC） and tensile experiments. The results show that with increase of the grafting degree （GD）, the inhibition effect on the internal space charge of VK-g-LDPE firstly increases and then decreases. Moreover, when the GD is 12.45%, the inhibition effect on the internal space charge of VK-g-LDPE is the best, the maximum charge density is 0.31 C/m^3, which is 95.87% lower than that of pure LDPE; with increase of the grafting yield, the crystallinity of VK-g-LDPE decreases, and the tensile strength of VK-g-LDPE firstly increases and then decreaseds the maximum tensile strength is 14.2 N/mm^2 when GD is 13.02%; the elongation at break and elastic modulus of VK-g-LDPE show a decreasing trend with increase of the GD.