预氧化聚丙烯腈纳米纤维膜声学性能研究

Acoustic performance of electrospun preoxidized PAN nanofiber membrane

通过对静电纺丝聚丙烯腈(PAN)纳米纤维膜进行预氧化处理,制备了声学性能优异的预氧化聚丙烯腈(OPAN)纳米纤维膜。研究了纳米纤维直径和孔隙率对声学性能的影响,结果表明:OPAN纳米纤维膜在全频率范围(1 k~10 kHz)内的声损值为-2.01 dB~+3.12 dB,且随着纳米纤维直径的增加,声损值呈增大的趋势。为了提高OPAN纳米纤维膜的模量,在PAN纳米纤维膜中引入了聚酰胺酸(PAA),在PAN预氧化的同时,PAA被热亚胺化,最终得到OPAN/PI纳米纤维膜。当OPAN/PI质量比为7∶3时,纳米纤维膜具有最高的杨氏模量(2000.07 MPa)和最低的声损值1.24 dB(1000 Hz)。此外,与OPAN纳米纤维膜相比,OPAN/PI纳米纤维膜因其杨氏模量更高,在低频(100-1000 Hz)范围内声损值更低。

Preoxidized polyacrylonitrile(OPAN)nanofiber membrane with excellent acoustic performance was prepared by the preoxidation of electrospun PAN nanofiber membrane.The effects of nanofiber diameter and porosity on acoustic performance were studied,and the results showed that the sound loss value of OPAN nanofiber membrane in the full frequency range(1 k~10 kHz)was-2.01dB~+3.12dB,and the sound loss value increased with the increase of nanofiber diameter.As to promote the modulus of the OPAN nanofiber membrane,polyamic acid(PAA)was introduced into the PAN nanofiber membrane,and while the PAN was preoxidized,the PAA was thermally imidized to finally obtain the OPAN/PI nanofiber membrane.When the OPAN/PI mass ratio was 7∶3,the nanofiber membrane had the highest Young's modulus(2000.07 MPa)and the lowest sound loss value of 1.24 dB(1000 Hz).In addition,OPAN/PI nanofiber membranes showed lower sound loss values at low frequencies(100-1000 Hz)compared with OPAN nanofiber membranes,owing to the higher Young's modulus.