C n F 2 n +1(VDF)x –(CH 2)p –的合成 其中n = 2,4; x = 2、3、4; p = 0、1、2和VDF以及 分别代表偏二氟乙烯(VDF)和I,OH或CO 2 H的代表。首先,在各种实验条件下研究了VDF与C n F 2 n +1 –I自由基端粒化以直接形成低分子量端粒的过程:引发剂,温度和溶剂有利于C n F 2 n +1(VDF的形成) )x I.在任何实验条件下,均观察到•C n F 2 n +1的区域选择性自由基加成自由基到VDF的亚甲基位置上。然后,在过氧化物引发剂的存在下,将这些VDF端粒进行乙烯化,同时对含VDF的碘化物反应物进行定量转化。R F(VDF)x C 2 H 4 I变成R F(VDF)C 2 H 4 OH的化学变化分为两个步骤:(i)由DMF /水的混合物(其含量为6/1导致最佳条件);(ii)随后是碱性介质,以将R F(VDF)x
telomerization reactions with 1,1-difluoroethylene and tetrafluoroethylene; other telomerization reactions of CF3I, C2F5I and n-C3F7I with 1,1-difluoroethylene and of n-C3F7I with tetrafluoroethylene are reported and the relative efficiencies of the iodides as chain-transfer agents are discussed. The telomeriodides have been coverted to useful models for some fluorocarbon polymer systems. A novel stereospecific
七氟-2-碘丙烷,iC 3 F 7 I,是与1,1-二氟乙烯和四氟乙烯进行端粒化反应时非常有效的链转移剂。报告了CF 3 I,C 2 F 5 I和nC 3 F 7 I与1,1-二氟乙烯以及nC 3 F 7 I与四氟乙烯的其他端粒化反应,并讨论了碘化物作为链转移剂的相对效率。端粒碘化物已覆盖到某些碳氟聚合物体系的有用模型中。顺式-(CF 3)2的立体定向合成报告了CF·CHCHF。
Fluoroelastomer composition having excellent processability
申请人:——
公开号:US20020002248A1
公开(公告)日:2002-01-03
Fluoroelastomers which contain copolymerized units of a fluoroolefin cure site monomer of the general formula
R
f
—(CH
2
CF
2
)
n
—CH═CF
2
,
wherein R
f
is a C
1
-C
6
perfluoroalkyl group or a C
1
-C
6
perfluoroalkoxy group and n is an integer from 1-3, exhibit excellent physical properties and processability when cured with polyhydroxy compounds.