Document 2XV3pmp52499wnq7z4oKaKK7

uc *4-a co^r:sc?o;j3=:':52' PLAGT3CG D3VlS!Or4 /y (Nj.HW to;al.en y4 . oe-ar.^on "' v. ** r *,*_*..* i. lVl>vi ^n r- . ^ , " i * * r- , - ^ v;. h*_" v. 4 wy ^ l w * -w'.Xi Copy to RIVER KCAO, COli^D nftOGK, MfW lERSfY (a-uj i>jf* * w-. Jfijino/Mij O^pt. A :*, * *-* ) --^ - > ii Alitwtfiog UtUf <faf* subi< i\>iymerisaiion Proc_so-o Mr. J. Ii*-.Vil.'tJ.ssjn - NY Hr. U. L. Zutzy - BE Attached for your reference is an article cntitlou "Mass Polymerization of Vinyl Chloride in the Presence of Acceptors of jl^oro^wii Ciiloriuo* ^rom eovlev Piastres Anno lo-^o* They toneluoo that the introduction of 2X1 acceptors into the reaction me-iur.; will accelerate polymerization. Also tae addition of stabilizing abciitives in the reaction vili increase the stability anu reduce ce^ree of branching. Thin ioay bo of value in our non-solvent process or contemplates Pcchiney-Ct. Gobain Process. Could our intermittent problems on the thermal stability of suspension resins be related to ilCl in the monomer? HJ?:er Att. ucc 040814 / natc indicate that the addition of (M % benzoyl peroxide gives a slight increase in the time of gel formation. Cobttli imphlhcmitc, Co", % Fig. 6--Dependence of the gel formation time on the competition of the initiating systems: I--02% mcthylethyikctone peroxide; 2-0-2% mcthylclhylkctonc peroxide -- 01% benzoyl peroxide; 2--0-2% methyl* etnylketonc peroxide -- O'2% benzoyl peroxide; 4--O'2% methylethylkctone peroxide -r 0'S% benzoyl peroxide; S-O-2% methylethylketone peroxide -r 0-8% benzoyl peroxide; 6--0-2% methylethylketone peroxide + 10% benzoyl peroxide. On increasing the amount of benzoyl peroxide to 0-2-0-5% we observe a reduction in the gel formation time, but a further increase to 0-8-1 % gives an increase in this time (Fig. 6). The degree of hardening in this case cither remains at the same level or increases some what; the mechanical properties basically remain without change. This discrepancy with the data in the literature may be a result of the use of peroxides of different grades or of different methods of hardening. It is well known that the gel formation time may be considerably reduced by adding a tertiary amine to an initiator system consisting of a peroxide or hydro peroxide initiator and a cobalt hardener. We investigated the influence of the co-accelerator dicthylaniline on the gel formation time and the degree of hardening of PNA-ED-2 polyester resin when using the following initiating systems: isopropylbenzene hydroperoxide--cobalt napiuhenatc; methylethylketone peroxide--cobalt naphthenatc. It was founu that the addition even of small amounts of dicthylaniline (0-02%) leads to a marked reduction in the gel formation time (to 10 min). A further increase in the ante ant of co accelerator has little effect on the rate of gel formation of PNA-ED-2 resin. The mechanical propert.es remain on the same level as when using systems with one accelerator, while the degree of hardening is reduced in many cases. Since acceleration of gel formation is possible when using systems with one accelerator, the addition of a co-accelerator is desirable only where the hardening of the resins has to be carried out at temperature below 20C. Conclusions 1. For the cold hardening of PNA-ED-2 resin the most suitable arc two-component systems based on methyicthylkctonc and cyclohexanone peroxides with a cobalt accelerator. 2. Thrce-componcnt systems (methylethylketone per oxide--benzoyl peroxide--cobalt napiuhenatc and cyclo hexanone peroxide--isopropylbenzene hydroperoxide-- cobalt naphthenate) have no advantages over twocomponent systems. 3. The use of diethylaniline as a supplementary accelerator in the systems isopropylbenzene hydro* peroxide--cobalt naphthenate and methylethylketone peroxide--cobalt naphthenate gives a marked reduction in the gel formation time without changing the mechan ical properties. Bibliography 1. Z. V. Mikhailova and P. Z. Li, Soviet Plast. No. 1, 1964 (translation of Plast. Massy, No. 1, 1963), p. 13. 2. I. W. Cywinski, Appl. Plast., 3, 2, I960, p. 36 (sic). 3. I. W. Cywinski, Reinf. Plast., 4, 3, 1960, p. 8. 4. P. Z. Li el til.. Plast Massy, No. .2, 1939, p. 19. 3. I. W. Cywinski and P. Stopp. Kunstst. Rundschau, 8,12, 1961, p. 393. 6. S. I. Omel'chenko el at., Soviet Piast., No. 2, 196.5 (translation of Plast. Massy, No. 2, 1964), p. 20. Mass polymerisation of vinyl chloride in the presence of acceptors of hydrogen chloride V. I. Tomashchuk, i. B. Kotlyar, A. M. Sharetskii and E. N. Zil'berman Translated by R. J. A. Hendry rT,HE production of PVC by polymerisation of vinyl X chloride in the mass is of interest because of the brevity of the process. There is no need for an aqueous dispersion medium, emulsifiers or emulsion stabilisers, and the stages of filtration of the suspension and drying of the polymer, occurring in the usual emulsion and suspension methods will also be obviated. The major obstacle preventing the widespread indus trial use of this method arises out of difficulties in uniform removal of the polymerisation heat with consequent local overheating, and dehydrochlorination of the polymer. Therefore the PVC produced by poly merisation of vinyl chloride in the mass usually has low heat-resistance, a wide molecular weight distribution and probably a more branched structure. When the degree of conversion exceeds 60-65% the quality of the polymer is reduced still further1, and the heat removal is greatly impaired because of the virtual absence of a liquid phase. To improve the quality of the polymer, additives which combine with hydrogen chloride* are added to the monomer. n ucc 040815 * authors studied the effect of certain , , sr- ;v`*,.',,.*.lly as stabilisers of I'VC (stearates o '.v. J. barium, cadmium, calcium and also epoxy com- pou'-ds) on the polymerisation of vinyl cltloride in the mass, and investigated certain properties of the polymer. Experimental method The vinyl chloride was polymerised in a horizontal rotating cylindrical 10 1. reactor of Kh 18 N steel. Mixing was effected by means of a roller which rolled around the cylinder wall as the reactor rotated. To 100 parts (by weight) of the monomer 0-2 parts of a,a'-azobisisobutyronitri!e were taken (or 0-25 parts of lauryl peroxide), and also 6-5 x 10-4 mol of the metal stearates (or 0-625 g of an epoxy compound). The reagents were added to the reactor immediately before the vinyl chloride. The amount of the additives was determined as follows. An empirical method was used (with lead stearate as an example) to determine the least amount of the stabiliser (6-5 X 10-4 mol ph parts of the monomer) which would ensure the highest yield of the polymer in a certain time. However, on investigation of the properties of the PVC it was difficult to determine the very small amount of metal stearate remaining in the polymer after several reprecipitations from a 1 % solution in cyclohexanone. It was therefore necessary to increase the content of metal stearates to 6-5 X 10"* mol. The Huggins constant (k1) was calculated1 from the data obtained. The PVC was reprecipitated from 1 % solution in cyclohexanone with cooled methanol. The kinetics of the decomposition of a.a'-azobisisobutyronitriic in the presence of lead stearate were determined in toluene by the amount of nitrogen evol ved4*4. The rate of polymerisation of vinyl chloride in the presence of HC1 was determined in ampoules, the polymer formed being weighed a certain time after the ampoules had been opened. It will be seen that the rate of polymerisation of vinyl chloride increases in the presence of certain additives, but not to the same extent in each case. Certain epoxy compounds4*7-" are effective stabilisers of PVC. Fig, 1 shows that ED-5 resin lias an inhibiting effect on the polymerisation of vinyl chloride, which is probably due to the presence of phenolic residues in the ED-5. On the other hand the addition of an aliphatic epoxy compound (a product of the condensation of cpichlorohydrin and ethylene glycol) noticeably in creases the rate of polymerisation of vinyl chloride. Fig. 2--Kinetict of polymerisation of vinyl chloride in the moss at S0C (initiator: lauryl peroxide): I--without HCI acceptor; 2--in pretence of Itod stearate. Fig. 2 shows the kinetics of the polymerisation of vinyl chloride in the mass with lauryl peroxide as, initiator. In this case also the rate of polymerisatiorbaf vinyl chloride is appreciably increased in the presd,Zs of lead stearate. The increase in the rate of polymerisation of vinyl chloride may be due to the combination of the HCI, which is probably capable of inhibiting polymerisation. Discussion of results The kinetics of the polymerisation of vinyl chloride in the mass in the presence of HC1 acceptors are shown in Fig. 1. Fig, 3--Kinetics of polymerisation of vinyl chloride in the most at Sff'C (,initiator; tz,u.'-azobitisobutyronitrile): I--in absence of HCI; 2-- in presence of HCI on weight of monomer). Fig, /--Kinetics of polymerisation of vinyl chloride In the matt at SQPC in the pretence of acceptors of HCI (initiator: d.a'ozobiusobutyronirrile). HCI acceptor: /--none; 2--calcium stearate; 3--aliphatic ennvv compound; 4--barium ttearate or cadmium stearate; b--lead stearate; b-EO-S epoxy retin. To verify this a study was made of the rate of poly merisation of vinyl chloride in the presence of HCI. Fig. 3 shows that the rate is noticeably reduced by the presence of 0*8% of HCI on the weight of the monomer. Moreover in view of the increased rate of polymerisation of vinyl chloride in the presence of stabilising additives, there is a suggestion of their accelerating effect in the decomposition of the a.a'-azobisisobutyronitrile. The rate constant of decomposition of a.a'-azobisisobtuy- ronitrile in the presence of lead stearate was therefore determined (Table 1). 12 ucc 040816 ;h,,t ;uc constant ol the rale of dccompoa.non docs not increase in the presence of lend stearate. TABLE I Rate of hreaLdown of a, a'-a7.nli;.s;sobut}TonitriIc in _______ presence of lead stearate in toluene_______ Amount of lead | stearate* mol per mot 1 of initiator \ Temperature* 9C ) k x 10\ see-1 0 7-74 x 10 ` 7-74 x 10 1 7-74 x 10 | | 84 84-10 83-8 84 ! j 1 3-0 3-6 2-8 3-1 The values of k given in the Table agree well with the published data obtained in a study of the decompo sition of a.a'-azobisisobuiyronitrilc without additives; consequently, the lead stearate present in the poly merisation medium has no effect on the rate of de composition of the initiator. The combination of the hydrogen chloride evolved during polymerisation of vinyl chloride may affect not only the rate of the reaction but also the properties of the polymer. It was shown in4 that even a low degree of dehydro chlorination of the polymer further increases its sensitiv ity to various factors, particularly that of temperature. Therefore the suppression of dchydrochlorination in the polymerisation of vinyl chloride should improve the heat stability of the polymer, which is confirmed by Table 2. TABLE 2 Heat stability and decomposition temperature of PVC produced in presence of lead stearate (0-59% 00 weiaht of polymer) No, of repre- cipitation Characteristics PVCpro- duced in PVC mixed PVC with presence with a out a of a sta stabiliser stabiliser biliser 0 : Decomposition i temperature, *C 170 ; Heat stability, min 10 i Lead content, % 0155 1 167 1! Ditto 20 1 007 173 2{ Ditto 17-5 ! 0-04 166-5 31 Ditto 10-5 1 NU 166 41 Ditto 10 NU i 166 5 Ditto 10 1-- 171-5 12 0-16 165 3-8 0-12 167-5 4-0 0-033 164 1-75 Nil __ -- --* --* 125 1-5 -- 144 --1-5 142 1-6 --a. 140 1-5 -- -- __ -- -- -- The PVC produced in the presence of lead stearate and with subsequent complete removal of the latter by means of repeated reprecipitation from cyclohexanone retains its high decomposition temperature and heat stability. At the same time PVC produced in the absence o* lead s,ea*,ttC oa, mixed wi,,. it ia me mixer, after reprcc;p;uViiori uncer ibairns coruiijoi *oscs ihc hi^h hciifc o; the p>M.\Lurc* Thus Tabie 2 shows that PVC produced ir. the presence of an KCi acceptor acquires higher intrinsic heat stability, ihe higher decomposition temperature of the ?VC mixed with the stabiliser and titer, reprecipitated, compared with the decomposit.on temperature of the initial PVC, is probably due to partial washing out of low-moiccular fractions of the polymer during re precipitation. TABLE 3 Intrinsic viscosity nt.n lie;,;;,ns' e, ''i-..s of TVC pfO^UCCd SdultiVCS) iii'.U IVliil iom to po]ynicri.s:;;io:i a;eJ^n, Content of [ Degree of No. of lead stearate conversion : Intrinsic vis* experiment j in PVC. V. ; ofmono- j costly, [rj liter, % , liutjzms* constant, k i o ! 60 ! 0-855 0-62 i 0 , 60 i 0-86 0-61 3 10 70 0-83 0-55 4 1 1-48 60 1 -12 0-32 5 1 0-7S5 S3 l `06 0-36 6 i 100 S3 : 0-94 ; 0-40 Table 3 gives the data on the intrinsic viscosity of PVC produced without additives, and alsc with the addition of lead stearate; also the calculated Huggins' constants, indicating the relative branching of the polymer*. It shows that PVC produced without HC1 acceptors has macromolecular structure with a consider ably higher degree of branching. At the same time relatively greater linearity of the structure is obtained even with a conversion adjusted to 83-S5 % (experiments 5,6) when considerable overheating should occur in places on account of poor heat transfer. Conclusions 1. In view of the inhibiting action of HC1 on the poly merisation of vinyl chloride, the introduction of KCI acceptors into the reaction medium accelerates the polymerisation. 2. The introduction of stabilising additives ir. the polymerisation of vinyl chloride in the mass increases the intrinsic stability of the polymer, and reduces the degree of branching. Bibliography 1. I. B. Kotlyar and A. M. Sharctskii, Soviet Plast., No. 2,1966, (translation of Plast. Massy, No. 2, JS6J). 2. K. Bik, Polimcry, No. 7-3, 1962, p. 244, 3. M. Imoto, J. Soc, Organic Chem, (Japan), 14, No. 1. 1956, p. 10-19. 4. O. Ya. Gordon, " Stabilisation of synthetic high polymers ", 1963, translation in English, 1964. 5. C. G. Ovcrbergcr et al., J. Am. Chem. Soc., 71, 19-19, p, 2661. 6. C. H. Bamford, W. G. Barb, A, D. Jenkins and p. F. Onyon, " Kinetics of vinyl polymerisation by radical m-rchanisms ", 1938, (Russian version, 1963), p. 248. 7. E. N. ZiTberman, " Progress in polymer chemistry and tech nology ", No. 3, 1960, d. 83. 8* " Ageing and stabilisation at polymers ", cd. M. B. Nclnran, 7C uce 040817