咪唑基离子液体Br[C_(14)im](CH_2)_4[C_(14)im]Br对PP结构与性能的影响

应用Gemini型咪唑基离子液体和聚丙烯(PP)熔融共混,制备出Gemini型咪唑基离子液体改性PP,并对改性PP的结构与性能进行了表征与测试.研究结果表明,BrC14im](CH2)4C14im]Br添加到PP中后,起到了异相成核的作用,同时使PP晶体结晶度减小;添加离子液体的样品熔融峰温,结晶峰温与纯样相近,同时离子液体也诱导了PP中α晶的生成;Gemini型咪唑基离子液体可以提高PP的抗静电性能,加入量为3 phr时,表面电阻率为8.97×109Ωcm,抗静电性能优良;此外,添加离子液体后样品拉伸强度有所降低,冲击强度有所提高,断裂伸长率有所下降,降低了PP的玻璃化温度,说明离子液体对PP有增塑作用.

THE INFLUENCE OF Br[C_(14)im](CH_2)_4[C_(14)im]Br ON THE STRUCTURE AND PROPERTIES OF PP

Polypropylene(PP)/1,4-bis(3-tetradecylimidiazolium-1-yl)butane bromide(BrC_(14)im](CH_2)_4C_(14)-im]Br) blends were prepared via melting blending,and then the structure and properties of the blend were characterised and tested.Results of testing indicate that BrC_(14)im](CH_2)_4C_(14)im]Br could have a heterogeneous nucleating effect in the PP matrix.Moreover,PP was readily to form α-crystal in the PP crystallizing process with the help of BrC_(14)im](CH_2)_4C_(14)im]Br.XRD data show the crystallizing process of PP could be affected by BrC_(14)im](CH_2)_4C_(14)im]Br,and thus decreased the crystallinity of PP.DSC results show the melting point and the crystallization temperature of PP/BrC_(14)im](CH_2)_4C_(14)im]Br blends was close to that of neat PP,this maybe due to the good compatibility of PP to BrC_(14)im](CH_2)_4C_(14)im]Br with long alkyl chains.In addition,the presence of BrC_(14)im](CH_2)_4C_(14)im]Br could improve the antistatic properties of PP apparently,and the surface resistivity of the PP was decreased to 8.97×10~9 Ω cm when the content of BrC_(14)im](CH_2)_4C_(14)im]Br in the blends was about 3 phr.As for the mechanical properties,the tensile strength decreased while the impact strength of materials presented the opposite results with BrC_(14)im](CH_2)_4C_(14)im]Br incorporated into it.DMA results show the glass transition(T_g) of PP also decreases when 3 phr BrC_(14)im](CH_2)_4C_(14)im]Br exists in its matrix.Therefore,BrC_(14)im](CH_2)_4C_(14)im]Br has the plasticized effect on the PP matrix in our experiments.