The present invention provides a fluorinated ionomer [polymer (I)] comprising recurring units derived from at least the following monomers: (i) 5 to 50 % by weight of a fluorinated monomer [monomer (A)] containing at least one -SO2X functionality, preferably having the formula of CF2=CF-O-(CF2CF(CF3)O)m-(CF2)nSO2X (I) wherein m is 0 or 1, n is an integer between 0-10, and X is selected from F, OH, and O-Me+, wherein Me+ indicates an alkali metal ion or an ammonium cation of formula NR4 + where each R independently represents a hydrogen atom or a monovalent organic radical selected from aliphatic radicals having from 1 to 8 carbon atoms and arylic or alicyclic radicals having from 3 to 8 carbon atoms; (ii) a non-functional fluorinated monomer [monomer (B)] having at least one ethylene unsaturation; and (iii) a fluorinated polyfunctional compound having the general formula: (CR1R2=CFCF2-O)a-Rf-((O)c-CF=CR3R4)b (ll) wherein: a is an integer equal to or larger than 1, preferably a is 1, 2, or 3; b is 0 or 1 and the sum of a and b is an integer equal to or larger than 2; c is 0 or 1; R1, R2, R3 and R4 are independently selected from F, H, alkyl, alkoxy, polyoxy alkyl, perfluoroalkyl, perfluoroalkoxy or perfluoropolyoxy alkyl, preferably F; and Rf represents a hydrocarbon or fluorocarbon group having at least two carbon atoms. The low-EW perfluorinated ionomers made of polymer (I) are adapted to be processed into thin films, which are found to have superior physical stability than the existing products and are thus well suited for low humidity or high temperature electrochemical applications. Moreover, these low-EW ionomers are melt processable and have limited loss of volatile substances at their melt processing temperatures.
本发明提供了一种含
氟离子聚合物[聚合物(I)],其包含由以下单体所衍生的重复单元:(i)占重量5至50%的含有至少一个-SO2X官能团的含
氟单体[单体(A)],优选的
化学式为
CF2=CF-O-(
CF2CF(
CF3)O)m-(
CF2)nSO2X(I),其中m为0或1,n为0-10之间的整数,X选自F,OH和O-Me+,其中Me+表示公式NR4+的碱
金属离子或
铵阳离子,其中每个R独立地表示氢原子或从具有1到8个碳原子的脂肪基和具有3到8个碳原子的芳基或环脂基中选择的单价有机基;(ii)至少含有一个
乙烯不饱和度的非官能性含
氟单体[单体(B)];以及(iii)具有下列一般式的含
氟多官能化合物:(CR1R2=CF
CF2-O)a-Rf-((O)c-CF=CR3R4)b(II),其中:a是大于或等于1的整数,优选的a为1、2或3;b为0或1,a和b的和为大于或等于2的整数;c为0或1;R1、R2、R3和R4独立地选自F、H、烷基、烷氧基、聚氧烷基、
全氟烷基、
全氟烷氧基或
全氟聚氧烷基,优选为F;Rf表示具有至少两个碳原子的碳氢或
氟碳基团。由聚合物(I)制成的低等效重(EW)
全氟离子聚合物适合加工成薄膜,这些薄膜的物理稳定性优于现有产品,因此非常适合低湿度或高温电
化学应用。此外,这些低等效重离子聚合物是可熔加工的,并且在其熔融加工温度下挥发物的损失有限。