September 1947
1091
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
c~, of hydrogen. I n 1aborator;s ruits iiii~rt at ~ i i o q i l i i ~ t ~preferably Imtli riwilts can h e accomplished by passage of a rapid utreain of 11ry. ozypc,n-free hydrogen through the misture. Esterificaiion i t x i ? fakc, 1, t o screral hours, depending on the size of the batch :ind t h i ~c.ffic.ienc>.of the apparatus, and may be considered conijllotc Coi, practiral purpo n - l i i ~ na cold surfacc held again.Gt t lit, rlllrlet lKb!, shun-s I10 eo1 . i t this point the produc I i,,.i(lui>> O!I each end of every chain. The next step consists of H \':i~:u~init i ~ > a t n i e nduring t which tlic chain length is built up h y I,.t('i' itttcwiisnge (13,21) between d i e .indl units of po1yrnc.r n i t h i ~ , ~ i l l t : i n rliniiiiatioIi t of pl>-col11-hichdistills a ~ m y . This rcactinu , . 1. i I l i i ; . t t ~ a t ~ bjd tht, follon-iny getirial equation:
HO -((' IH? il -(O 1i E'III,rliib 5tc.p t hi, i ~ f l u xcoluiiin is rc~plsccdby a J tillation liriicl which is n-ired for heat and is kept at a tempei'aturc .uch that no condensate in it. The pressure i. reduced ilo\vly t i ) lcss than 5 nin fio\v of hydrogen bring adjustrd ac.rui~ili~igly, and plycaol illed off as fast a s it is formed. Sni:1ll : i i n o u i i t . iif cyc.lir ala0 are found i n the tii.~till:tte. 1h:i~r itit(~rc~h:tngc. i,i quite mpid a t first while tlic rnixtnrc. is liiiipiil, hut :ih t1io viscc~ity increaw:;, hecause of increa.sed molecul:ii, rveiplit, the, i ' t r t t . o r intei,(*li:ingoi:tll.> off, and a point is finully re:ic~lic~d a t v-hicli the rat.
SFBAC0-E
PA3-S
B E V Z O Y L PE90'13E
PER
30 P 4 9 T S 6LU
Figure 2. Tensile Strength of \-arious Pol) niers Loaded with 150 Parts RIapico 2 9 i as Related to 4mount of Benzoyl Peroxide Used i n Vulcanization
September 1947
INDUSTRIAL AND ENGINEERING CHEMISTRY
use of certain otic's ui the available finely dividcd pigments is undesirabltl for other reason'. Carbon hlaek, for example, cannot be used \vi t h be n z o y 1 p e r o s i d e - 1- u r csd stocks because they catalyze the dwnmpoaition of p
