聚丙烯腈改性纤维的结构表征及阻燃性能研究

Structure characterization and flame retardancy of modified polyacrylonitrile fiber

将聚丙烯腈(PAN)纤维与水合肼溶液进行胺化反应,制得胺化PAN纤维(PAN-H纤维),然后将PAN-H纤维与氯化锌(ZnCl_2)溶液反应制得Zn^(2+)螯合PAN纤维(PAN-Zn纤维);利用红外光谱、X射线光电子能谱研究了PAN纤维及其改性PAN纤维的结构,并对纤维的结晶性能、力学性能、阻燃性能、热稳定性能进行了研究。结果表明:在PAN纤维胺化过程中,PAN大分子的氰基(—C≡N)参与化学反应,生成了氨基(—NH_2),亚氨基(—C帯NH),酰胺等基团;在Zn^(2+)螯合过程中,Zn^(2+)会与—C帯NH,—C≡N,—NH_2和酰胺基上的N—H键上的N原子以及酰胺基中的O原子进行配位反应; PAN纤维、PAN-H纤维、PAN-Zn纤维的结晶度分别为55. 0%,38. 7%,38. 1%,断裂强度分别为3. 76,2. 63,2. 90 cN/dtex,断裂伸长率分别为35. 96%,20. 63%,33. 6%,极限氧指数(LOI)分别为19. 8%,20. 0%,33. 6%; PAN-Zn纤维经皂洗10,20次后其LOI分别为33. 6%,32. 8%,具有良好的阻燃性能;与PAN纤维相比,PAN-Zn纤维初始分解温度略有降低,但最大分解温度和残炭均明显升高,其在700℃下的残炭率提高了20%左右。

Aminated polyacrylonitrile fibers( PAN-H fibers) were prepared by amination of PAN fibers with hydrazine hydrate solution. Zn2+chelated PAN fibers( PAN-Zn fibers) were prepared by reaction of PAN-H fibers with zinc chloride( ZnCl2) solution. The structure of PAN fibers and their modified PAN fibers were studied by infrared spectroscopy and X-ray photoelectron spectroscopy. The crystallinity,mechanical properties,flame retardancy and thermal stability of the fibers were also studied. The results showed that the cyano group of PAN macromolecule participated in the chemical reaction and formed —NH2,—C=NH,amide bond etc. during the amination process of PAN fibers; Zn2+will coordinate with —C=NH,—C≡N,—NH2,N atom of N—H bond on amide group and O atom of amide group in the process of Zn2+chelation; PAN,PAN-H and PAN-Zn fibers had the crystallinity of 55. 0%,38. 7% and 38. 1%,the breaking strength of 3. 76,2. 63,2. 90 cN/dtex,the elongation at break35. 96%,20. 63% and 33. 6%,and the limiting oxygen index( LOI) of 19. 8%,20. 0% and 33. 6%,respectively; the LOI values of PAN-Zn fibers were 33. 6% and 32. 8% after soaping 10 and 20 times respectively; compared with those of PAN fiber,the initial decomposition temperature of PAN-Zn fibers decreased slightly,but the maximum decomposition temperature and carbon residue both increased significantly,and the carbon residue rate increased by about 20% at 700 ℃.