RESEARCH
N E W F L U O R O C A R B O N DIENES . . . • · · P o i n t «to H i g h P e r f o r m a n c e P o l y m e r s ( E l a s t o m e r s ) 1,1,2,3 tetrafluoro-l,3-butadiene (dihydroperfïuoro butadiene)
CF*
CF -
fiuorocarbon structure for beat and oxidation stability, solvent resistance
CF == CH
terminal methylene group to induce polymerization and enhance l o w temperature performance
• . · Hint a t N e w Type of Chemical Intermediates PerRuoro (vinylcyclobutenes) CF2 -
CF — C =
CF
CF 2 = C F — C F — CF I
CF,
II
CF2 — CF
CF 2
polymerizations, unique addition products (particularly nucleophiîîc atrack^, i.e., with alcohols, amines, e tc»)
Fluoro Polymers And Intermediates Researchers uncover a p o tentially high performing fiuorocarbon diene a n d new ring f l u o r o dîenes
m
.c
Pennsalt researchers raised
s
NATIONAL b o t h industrial Industrial & MEETING and academic Engineering eyebrows at t h e Chemistry" ACS meeting with two brand new types of fiuorocarbon dienes: 1,1,2,3-tetrafhioro-l .3-butadiene. a potential key t o high performance polymers; perfluoro(vinylcyclobutenes^. unique fiuorocarbon dienes w i t h builtin ring systems. Preliminary studies o n the muchsought d i e n e m o n o m e r CF.j—CF—CF= C E , show that it readily polymerizes a n d copoly merizes, Murray Hauptschein told the Division of Industrial and Engineering Chemistry. Moreover. the u n t r e a t e d r a w h o m o p o K m e r , a stiff 48
C&EN
SEPT.
2 2,
1958
elastomer, softens in the 500° F . range without decomposing. This points the way to possible use as an elastomer for high-temperature service in missiles and aircraft. • Complex Routes. After several unsuccessful tries by various possible olefin addition reactions, the Pennsalt research team m a d e u p of H a u p t schein. H y m a n Iserson, a n d Francis E. Lawlor hit upon a multi-step process to make the dihydroperfluorobutadiene. It involves lithium aluminum hydride reduction of ethyl-3,4-diehloroperfiuorobutyrate t o the alcohol, 3,4-dichïorol.l-dihydroperfluorobutanol. The latter is converted to the iodide, 3,4dichloro-1.1 -dihydro-1 -iodoperfluorobutane via the corresponding tosylate. Route to t h e perfluoro ( vinylcyclobutenes) involves thermal reaction of 1,2dichloro-1,2.2-trifluoro-l-iodethane with perflnorocyclobutene to
