Synthetic Elastomers as Plasticizers for Polyvinyl Resins

The fugitive tendency of ester type plasticizers is reduced by addition of small amounts of rubberlike 1-3 butadiene-acrylonitrile copolymers. The Per...
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Synthetic Elastomers as Plasticizers for Polyvinyl Resins J J D. K.TOUSG .ASD K. G. NEWBERG Standard Oil Development Company, Elizabeth, S. J .

R . 31. HOWLETT Enjay Company, Inc., 26 Broadway, New York, !Y.I’.

tion of total plasticizer is above 3270 by weight. Tensile tests indicate that the high acrylonitrile type copolymers are more compatible in dioctll phthalateplasticized VYSW than are the low acrylonitrile copolymers. The Perbunan-VYNW and Perbunan-VYXW-dioctyl phthalate blends show better aging properties than VYSW-dioctyl phthalate blends when held 6 to 14 days in a n air oven at 250’ F. Perbunan-VYNW blends show improved light aging properties when the Perbunan is held a t about 12.5 to 50 parts on the Vinylite. The processing properties of Perbunan-VYNW blends are improved by the addition of S-polymers. The blends can be extruded to form a smooth tube a t 220” F. The aging property of PerbunanVYSW and Perbunan-VYNW-dioctyl phthalate blends may be improved by adding S-polymers to the blends.

Addition of Perbunan 26 or Perbunan 35 to a vinyl chloride resin decreases the amount of ester type Plasticizers necessary to obtain equivalent or better physical properties. The fugitive tendency of ester type plasticizers is reduced by addition of small amounts of rubberlike 1-3 butadiene-acrylonitrile copolymers. The Perbunan 324s VYNF-dioctyl phthalate blends have good oil resistance. The blends show only slight change in volume when tested in the A.S.T.R.I. standard hydrocarbon liquids. Other advantages which Perbunan 26NS or Perbunan 35NS impart to a VYNW plastic compound are improved elongation and low temperature properties as evaluated by brittle tests. Blends of Vinylite VYNW-Perbunan 35NSdioctyl phthalate exhibit higher tensile strengths than dioctyl phthalate-VYNW systems, particularly if the concentra-

T

HE importance of a plasticizer in polyvinyl chloride and its copolymers is second only to that of the resin itself. The

kind and amount of plasticizer determine to a large degree the properties of the final composition. I n 1941 Fuoss ( 1 ) stated that plasticization is the addition of a substance of relatively low molecular weight to a high polymer. I n the last few years, however, a number of workers have concentrated on the use of highmolecular-weight materials as plasticizers for rubbers and resins. A few investigators have reported on the physical properties of polyvinyl chloride plasticized with rubberlike copolymers of 1-3 butadiene and acrylonitrile. Henderson (2), Kinkelmann (r), Moulton (I), and Kenney (S) have published data on rubberresin blends. In this paper the authors present results of the

I

g

iaoo

Y

a

4

avi

1600

m

-I

I c 0

STOCK

1400

a IY) w

STCARIC ACID

i

5

v)

1200

c

1000

I 5

, IO

I

I

15

20

I 25

MINUTES TIME POLYMER MILLED IN VYNW AT 2 6 0 - 280’F

I 30

plasticization of Vinylite (VYNW), a copolymer containing 95 yo of vinyl chloride and 5% of vinyl acetate, by the use of several synthetic elastomers such as Perbunan and Spolymers (6, 6). The main object of the work is to report recent results with Perbunan NS-VYNW blends as well as Perbunan NS-dioctyl phthalate-VYNW blends. The Perbunan NS polymers are a commercial class of butadiene-acrylonitrile copolymers stabilized with an improved nonstaining and nontoxic antioxidant (stabilizer 8567). The term “XS” indicates nonstaining. In this study the total plasticizer concentration was varied over a wide range. The increments were small enough so that any deviations from expected normal behavior would be disclosed. Coupled with this study, control investigations were carried out on the conventional VYNW-dioctyl phthalate system. The ester type plasticizers, etc., are required to obtain processing properties in the rubber-resin type blends. Another phase of the present investigation covers the use of S-polymers (styrene cow polymers) in Perbunan-VYNW blends as well as the use of S-polymers in Perbunan-VYNW1600 d dioctyl phthalate blends. The Spolymers were m i evaluated in the Perbunan-Vinylite system, as L c U they showed excellent aging properties and good compatibility in the system. The resin copolymer (Vinylite, VYSW) chosen Y for the work was obtained from the Bakelite Corporation. It contained 957, vinyl chloride and 5% vinyl acetate. The dioctyl phthalate made from 2-ethyl hexyl alcohol was supplied I1000 by Ohio Apex, Inc. The basic formulation in parts by weight was as follows:

Figure 1. Effect of Mill bIixing Time on Tensile Strength of Perbunan 3SNS 90-VYNW Blends

1446

Copolymer (YYNW) Vinylite stabilizer Stearic acid Plasticizer

100

3 !.5 Variable

November 1947

INDUSTRIAL AND ENGINEERING CHEMISTRY

OF MILL ~ I I X I STINE G ON PHYSICAL PROPERTIES OF TABLEI. EFFECT PERBUNAN 35NS BO-VYNW BLENDS

(Formula: T-YNW 100; basic lead carbonate, 3: stearic acid, 1.5; Perbunan 35KS 90, 5 0 ; dioctyl phthalate, 50) 1 2 3 4 5 6 7 8

Btock No.

1447

250" F., light aging, and volume increase in A.S.T.M. reference fuels No. 1, S o . 2, KO.3, and water. P R E P A R A T I O h OF SAMPLES

MILLINGPROCEDURE. A number of qualitative experiments vere performed with the rubberresin mixtures in order to determine the best 10 10 30 30 5 5 3 3 mixing time and temperature. I n this prelimi0 15 0 15 0 15 0 15 nary mixing work a number of blends were made on a 6 X 12 inch mill a t 260-280" F. Time of 1710 1750 1600 1610 1080 1050 1200 1110 milling varied from 3 to 30 minutes. Coupled 370 210 320 260 2iO 320 250 220 75 72 72 75 70 72 73 TO with this part of the investigation it seemed 190 245 190 255 215 225 190 175 desirable to determine the effect of cold milling. Sol. Sol. Sol. Sol. Not P a r t Sot Kot Half of the hot-mill blends were, therefore, given sol. sol. sol. sol. an additional mill mixing a t 140" I?. for 15 minutes. Results of this vork, as well as results on a Perbunan type blend, are found in Table I. Some of the data are presented in Figure 1. Results show that a t about 280" F. higher tensiles viere obtained when the mill mixing was continued from 12 to 30 minutes. Additional mill mixing a t 140" F. for 15 minutes did not alter the tensile strength of the test blends; however, tear resistance was reduced. A comparison of tensile and tear tests with the solubility data show that the best tensile and tear data mere obtained on the blends which were not completely soluble in cyclohexanone. This work indicated that, as the time of heating was increased, the Perbunan NS cross-linked to form a gellike structure. I t was apparent that this gel or improved dispersion was responsible for an improvement in the physical properties 10 20 30 40 50 10 20 30 40 50 as judged by tensile, tear, and lack of discoloration T O T A L PLASTICIZER COYCENTRATION TOTAL PLASTICIZER CONCENTRATION on light aging. (PCRBUNAN + DOP1,WEIGYT 'b (PERBUNAN + D O P ) , Y l X H T '/e Several attempts m-ere made to formulate blends Figure 2. 10Oq~AIodulus Plotted against Plasticizer Concentration in of the synthetic elastomers and Vinylite VYKW VYNW a t lower temperatures-that is, 140" or 200" F.; hovever. -good uniform blends were not DOSThe synthetic rubber plasticizer, such as Perbunan, was varied sible a t the low temperatures. All data indicate that for the best results the resin must be fluxed with the rubberlike plastifrom 12.5 to 150 parts, based on 100 parts VYXW. However, cizer. when the rubber plasticizer was used with dioctyl phthalate, it was varied from 25 to 75 parts, based on 100 parts VYNW, and The final milling procedure as developed from the study of mixdioctyl phthalate was varied from 12.5 to 50 parts by weight. ing conditions is given. The ingredients, with the exception of Fillers were omitted from the formulation so that properties of the synthetic rubbers, were weighed out and dry-blended by the compound would be a function only of the kind and amount hand. After blending, the dry mixture was treated, in a number of plasticizer used. I n most of the work basic lead carbonate of the experiments, n-ith dioctyl phthalate; and the blend was was used as a stabilizer for the VYXW and the stearic acid as a then charged to a 6 X 12 inch laboratory rubber mill heated witb parting agent; this facilitated easy release of the stock from the hot mill. The amounts of these two latter materials were kept constant. The TABLE 11. COMPARISON O F PHYSICAL PROPERTIES O F BLENDSOF rrYxw synthetic elastomers studied mere: Perbunan 35NS TITH VARIOUS TYPES OF PERBUSAN 90, Perbunan 26?;S, Perbunan 18, S-40, S-50, and Stock No. 1 2 3 4 5 6 S-60. I n this work the Perbunan polymers used Formula, parts by wt. had a 2-minute Mooney viscosity of 90. As the VPNW 100 100 100 100 100 100 100 Basic lead carbonate 3 3 3 3 3 3 3 Perbunan number increases the acrylonitrile in the Stearic acid 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Perbunan 12.5 25 37.5 50 75 100 150 copolymer increases, and, likewise, as the S number Perbunan in blend, %, 10.7 19.4 26.4 32.4 41.7 48.8 68.8 increases the amount of styrene in the resin inPhysical properties creases. The S-polymers are copolymers that conTensile, lb./sq. in. tain styrene. (The S-polymers are high-molecularPerbunan 18 4470 3080 1410 750 490 60 50 26h-s 6460 4710 3130 2540 1710 1380 890 weight aliphatic olefin-styrene copolymers. The 35%S 90 7610 7080 3900 2510 2650 2120 1800 Ultimate elongation, 70 products are now being made by the Standard Oil Perbunan 18 15 30 35 110 160 305 Company of S e w Jersey.) The tests carried out 26x5 60 70 iio 160 165 200 230 35NS 90 I5 40 225 295 270 235 210 on a number of the plasticized compounds were as Shore durometer hardness Perbunan 18 96 95 94 91 79 76 follows: 100% modulus, tensile strength, ultimate 69 97 26x5 97 93 93 89 86 70 elongation, Shore durometer hardness, brittle tem96 94 35riS 90 94 97 70 90 77 perature, specific gravity, weight loss, heat aging a t

Mill mixing procedures Dioctyl phthalate-VSh-K milled a t 280-285O F . , min. Perbunan 35SS 9 O - V S S F milled a t ?io0 F., min. Perbunan 35XS 9O-VYSnmilled a t 140' F., min. Physical properties Tensile, lb /sq. in. Ultimate elongation, % Shore durometer hardness Crescenttearat r o o m t e m p , lb./in. Soly. a t room temp. in 5% concd. cyclohexane

5

5

5

5

5

5

5

5

INDUSTRIAL AND ENGINEERING CHEMISTRY

1448

steam to abodt 280-300" F. Thc resiri was then fluxed about 2 minutes and alloJved to nlill lvith a rolling bank for 5 minutes with occasional cutting. To this plastic a t about 280" F. was added the rubber. 11111niiying was continued for about 12 minutes a t 280" F. The batch was then sheeted off the mill at 0.075to O.lj-inch thickness. l I o L D I s G METHOU. This operation was carried out in astanda i d A.S.T.11. four-cavity mold (Dl5-41) yielding slabs G X G X 0.075 inch. The niolding cycle was 10 minutes at minimum ram pressure at 280" F., then 10 minutes a t 900 pounds per square inch at 280' F. The stock was cooled under ureseure

TABLE 111. PHYSICALPROPERTIES O F PERBUNAN 18-VYNW BLESDSCONTAINING DIOCTYL PHTHALATE Stock K O .

1

2

3

4

Formula, parts by wt. VYNW Basic lead carbonate Stearic acid Perbunan 18 Dioctyl phthalate

loo 3 1.5 12.5 50

loo 3 25 50

loo 3 1,5 50 50

loo 3 1.5

Physical properties Tensile, Ib., sq. in. Ultimate elongation, % Shore durometer hardness

2450 310 83

2030 360 83

1380 330 79

1.5

75 50

~150

376 73

Vol. 39, No. 1 E

5

"03 1.5

100 50

320 155 69

TEST METHODS

T E S S I L E STRENGTH, ~ I O D U LAUK US , ULTIIIATE ELOXGATIOS.These tests m r e made on a model L-3 Scott tester at about 77" F. and 5 5 7 relative humidity. The rateof jaw separation was 20 inches per minute. For measurement of elongation the specimens w r e bench-marked with a 1-inch die, the grips were adjusted at zero load 3 )I inch apart, and the elongation was measured by means of a decimal scale held close to t,he specimen. SHORE D U R O M E THARDSES. ER These values were obtained using the Shore A durometer (.I.S.T.lI, D67614T). Multiple readings were taken on each specimen. BRITTLE TEIIPERATCRE. The instrument used to determine these values was t'hat described under .I.S.T.lI. D74644T. The specimens xere alloTved t o condition 25 minutes in air t,o reach equilibrium temperahre in the hat'h prior t o

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m d

2 rooo+ I-

I-DOP [DIOCTYL PHTHALATE) A-25 PTS PERBUNAN 35 NS 90

Y

r - 2 5 P T S PERBUNAN 2 6 N S

-

* - 5 0 PTS PERBUNAN 3 5 N S 9 0

*-5OPTS PERBUNAN 2 6 N S

1-75 PTS PERBUNAN 3 5 N S 9 0

'1-75 PTS PERBUNAN 2 6 N S

1

1

IO 20 30 40 50 T O T A L PLASTICIZER CONCENTRATION (PERBUNAN + 00Pl.WElGHT '10

Figure 3.

IO 20 30 40 50 TOTAL PLASTICIZER CONCENTRATION (PERBUNAN tDOP1,WEIGHT '/o

Tensile Strength Plotted against Plasticizer Concentration in VYSF

testing,

TABLEIV. PHYSICAL P R O P E R T I EO S F PCRRVSIN 35XS 90-V\iSTj7 BLESUS Stock S o . Formula, parts by n t . VYSW Basic lead carbonate Stearic acid Perbunan 35SS 90 Dioctyl phthalate Perbunan 35SS 90 in blend,

%

Dioctyl phthalate,in blend, 5% Total plastlclzer in blend, 70 Physical properties Tensile, lb./sq. i n . AIodulus a t loo%, lb./ss. i n . U t i m a t e elongation, 52 S h o w durometer hardness -.~... Specific gra\rity Brittle temperature, F. Weight loss a t 180' F.=, 70 Air oven method 72 hours 168 hours Vncorked A.S.T.11. tube method 72 hours 168 hpurs Volume increase at room temp.? 9 A . S . T . M . r i f e r e m e fuel KO. z 24 hours 168 hours A.S.T.1I. oil S o . 3 24 hours 168 hours h.S.T.AI. reference fuel S O . ~

1

2

100 3 1.5 25 12.5

100 3 1.5 23 25

17.6 8.8 26.4

16.2 16.2 32.4

13 9 27.9 41.8

30.0 7.6 37.0

27.9 13.9 41.8

24.4 24.4 48.8

3200 2790 220 93 1 290 -30

2920 1750 310 Si 1.250 -40

2380 880 380 72 1 218

2380

2120 1230 350 80 1 200 -40

1730 610 380 6J 1 181 -30

3

5

4

1400

-40

320 87 1 217 -40

-0.38 -0.89

-0.41 -0.90

-0 2-1 -0.30

-0 -0

-0.06 -0.10

-0

-0

11 -0 2 5

-0.07

-0

+0.05

-2 8 -15.4

+lO.5

A9.l +15,s

c 9 5 +4

0

3

3

i .a

23

1,: ,a 50

39 0 6 .5 45.5

36.7 I? 2 18.9

32.7 21 8 54.5

18.50 1160 280 84 1 181

1670

14-10 460 420 60 1.154 - 50

f10.1

80 I 180 - 40

-0 50 -0 80

-0

- 0 21 - 0 2'3

-0

-0 -0

40

12 -0 1,

-0

-0

Ici

-0 21

-0.19

+TO +?.5

-3.9 -12.6

A8 8 +6.5

-7 -3

8 6

+6 7 -3 0

2

4-0.5 +0.6

to

3 5

-0.B -0.1

-0 7 -0.5

-0 4 +0.3

-0.6 +3.1

-0.F -0.3

+0.1

-0.6 -0.5

-0.6 -0.6

+0.1

-0.8 -0.9

-0.8 -0.9

+O

-0.4

-0.2

1-1

70

Samples are 2 X 1 X 0.075 inch blocks.

i O . l

-0.n

-0 90 13 -0.20

-0 2

+0.5

+o 2

-0 -0

+O

4

-0 ;i +0.1

-0 6

+2.7

2

+0.1 +2.2

1 t 0 . l

-0 8 -0.7

-1.3 -0.7

0.0 +0.2

+0.2

1

1

23 hours 168 bourn Kater 24 hours 168 hours

50

- 0 33 -0.99

-0.6 -0.4

-0

-40

(130 310

50 93

-0.3

-0.3

100

100

19 -0 37

15 16

Y

8

I

:1 ;

-0

-0

G

-0

WEIGHT Lo-n. These values xerc obtained a t 180" F. Method A: The t,est samples n-ere held on a polished steel plate in an air oven; method B: the test samples were held in an uncorked A.S.T.11. tube heated esternally by the use of an oil bath. The tube was 300 mm. long and 38 mm. in outside diameter. T'OLUIIE ISCREASE. These values aere ohtained in standard laborat,ory fluids a t room temperature. SR-G or -4.S.T.X. D471-46T reference fuel KO. 2 F a s formulated from 60% diisobutylene. 20% toluene, 5Cc benzene, and 15Vc xylene. SR10 or .4.S.T.11. reference fuel S o . 1 is pure d i i s o b u tylene. A.S.T.M. oil No. 3 is a low TT.I. mineral oil with an aniline point a t 70" C.

INDUSTRIAL AND ENGINEERING CHEMISTRY

November 1947

TABLEv. Stock S o . Formula, parts b y w t . YYSW Basic lead carbonate Stearic acid Perbunan 2 6 K S Dioctyl phthalate

PHY-SIC.IL PROPERTIE? U F PERRCSAN

1

IOU 3 I,.? 2 .i 12.2

Perbunan 2 6 S S in blend, ( j L Dioctyl phthalate in blend, Total plasticizer in blend, ? Physical properties Tensile. lb./sq. i n . l l o d u l u s a t 1 0 0 5 , lb./'sq. i n Vltirnate elongation, Shore durometer hardness Specific gravity Rrittle temperature, O F. Keight loss a t 180' F . a , L: .tir oven method 7 2 hours 168 I ours I-ncorked .l.S.T..\I. rube method

. test about 35 O F. below that obtained nithdioctvlphthalate. _ RESULTS ON PERBUXAK-VYSW B L E N D S \-Yh-iV. These results are n-orthy of note, as dioctyl phthalate Table I1 presents results on F-YS\Y blends plasticized lvith is one of the better lo^ temperature type ester plasticizers now the several Perbunan polymers. These experimental data inused in Vl-X\T. Twenty-eis per cent plasticizer (formulated dicate, based on tensile results, that high nitrile type copolymers, by compounding 17.(ic; Perbunan 35SS 90 arid 8 . 8 5 dioctyl such as Perbunan 35SS 90 and Perbunan ZGSS, are more coniphthalate in the blends) gave a stock with a brittle temperature patible in VYXW than Perbunan 18. of - 4 0 " F. This result is rennarkahle considering t,he low amount of plasticizer employed. RESULTS 05 PERBUNAN h S-VYNW-DIOCTYL PHTHALATE F70LhTILITY T E ~ T YResults . in Tables IT, V, and VI show that BLESDS when the amount of plasticizer is held constant i n V T S \ V the tOOccL~ODULUS.This family of curves indicated that all thc Perbunan-dioctyl phthalate-VYS\T blends (2 X 1 X 0.075-inch plasticizers tested behaved similarly in F - Y S V (Figure Z), thr, test blocks~have less w i g h t loss at 180" F. than do dioctyl only difference being i n their relative plasticizing efficiencies. phthalate-VTST\- blerids. For example, stock 3 (Table I), The Perbunan 35SS SO-dioctvl phthalatc,-Vl?iW svstems g i n , plasticizeil with 13.0C; PtJrbunan 3SSP 90 and 2 7 . 9 5 dioctyl . . higher moduli, for the same total n-cight per rent plasticizer, than do Pcrbunan 261s-dioctyl phthalate-J-TS\\- systems. This rrsult is rather confusing a i it may indicate that Perbuiiaii P G S S is a b(3ttcr plasticizer for J7TS\T- than Perbunan 35SS :IO. However, this lon-er modulus for 90L___ o9--Perbunan 26x8 may he due, only to the fact tint t,his type of rubber is 1c.s compatible i n the tern. Tensile data tend to shon- this t o he t TESSILESTRESGTH.Except for the possitilc, esistencc of .:lighv plateaus in the curve- (Figure 0 3), it can br said that, viithin the limits stuAcd. tensile atrcngth is inversel?- proportional to con70 _ _ _ centration of plasticizer. H o x m - 5 0 PARTS t DOP t - 75 PARTS t DOP 35SS 90 dioctyl phthalate-iormulnteil blends 0 with VTS\T- had higher tensiles than ITISIT--dioctyl phthalate blends, provided eoncriitra_~ _ _ tions of total plasticizrr n-erc above 34C; by weight. \\'here tensile stwiigths are significant, I it seems desirable to use Perbunan 35 i n prefer25 30 35 40 45 50 55 ence to Perbunan 26 or Perbunan 18. This T O T A L PLASTICIZER CONCENTRATION (PLRBUNAN t DOPI. WEIGHT 1: observation is apparent from the results shown in Figure 3 and Table 111. (Perbunan 18 reFigure 4. Durometer Hardness Plotted against Plasticizer sults are not presented in the figures, as a comConcentration in VYNW - 0 Qc,

-0.63

..

TURE.

~

+

Y

1

INDUSTRIAL AND ENGINEERING CHEMISTRY

1450

Vol. 39, No. 11

TABLE VI. PHYSICAL PROPERTIES OF VYNW-DIOCTYL P H T H A ~ TABLEVII. AGING STUDYO N PERBUNAN 35% 90-VYNW ATE MIXTURE us. PERBUNAN-VYNW-DIOCTYL PHTHALATE BLEXDS MIXTURE Stock S o . Formula, parts by wt. VYKFV Bas& lead carbonate Stearic acid Perbunan 3 5 5 5 90 Perbunan 2 6 S S Dioctvl _ Dhthalate . Perbunan in blend, % Dioctyl phthalate in blend, % Total plasticizer in blend, % Physical properties (unaged) Tensile, 1b.isq. in. Ultimate elongation, % Shore durometer hardness Specific gravity Brittle temperature, ' F. Crescent tear a t room temp., lb./in. W t . loss a t 180' F. by uncorked A.S.T.M. tube method, % 72 hours 168 hours Volume increase a t room temp.&, % A.S.T.M. reference fuel No. 2 24 hours 168 hours A.S.T.M. oil S o . 3 24 hours 168 hours A.S.T.M. reference fuel S o . 1 24 hours 168 hours Water 24 hours 168 hours Physical properties (oven-aged for 3 d a y s a t 250° F.) Tensile, lb./sq in. Cltimate elongation, % Shore durometer hardness a

1

2

3

100 3 1.5

100 3 1.5 25

100 3 1.5

....

....

50 0 32.4 32.4 3000 280 86

1.250 - 20 420 -0.16 -0.23

....

25 16.2 16.2 32.4

2920 310 87 1.250 -40 380

2610 300 84 1,242 40 355

+4.0

0.0 -0.4

-0.6 -0.4

+2.2 +1.6

-4.0 +1.2

-0.4 +0.3

-0.9 -1.3

-0.4 -0.2

-0.6 -0.6

+l.Z +0.2

Under this test the dioctyl phthalate was far more volatile in sample A-1755-1 than in sample A-1907-2. These data indicate that a t 90" C. Perbunan helps to reduce the loss of ester type plasticizer. A study of volume increase data will indicate that Perbunan 35XS 90-dioctyl phthalate-VYNR blends show less shrinkage in the several solvents tested than do Perbunan 26NS-dioctyl phthalate-VYNW blends. The solvent resistance of the Perbunan 35KS 90 type blends is very good. HEATAGING. Tables VI, VII, and VI11 give data on the aging property of blends. The results indicate that \Then the amount of plasticizer is held constant the aging properties at 250" F. for the Perbunan-dioctyl phthalate-T'YNTV blends are as good as those of the dioctyl phthalateYYSIT blends. The data of the preceding paragraph indicate that less plasticizer is lost when Perbunan is present. The Perbunan-dioctyl phthalate-\'YKIT blends show good aging proper-

100 3

100

.

1 5

50

25 50

2940 270 80 420

2380 380 72 313

Physical properties (oven-aged for 3 days a t 250' F.) 2920 2260 Tensile, Ib./sq. in. Ultimate elongation, 70 160 140 Shore durometer hardness 85 70

*

2520 150 89

phthalate, lost o.25% in and stock 5, plasticized with 27.9% Perbunan 35XS 90 and 13.9% dioctyl phthalate, lost only o.17% in weight. To obtain better picture of lleat volatility some tests were made on a 0.5-mni. thick film in an air oven a t 90" C. for 11 days. Results are as follows:

50 9.9

100 3 1,s

3 1.5 50 50

Sample

A- 1907-2 100 3 1.5 25 25 2.5

630 0

370 0

4

1450 60 75

6

100 100 3 ' 3 1 , 5 1.5 75 100 50 50

1750 1410 380 420 65 60 2i5 235

1240 420 55

170

880 45

70

750 15 90

1310 20

670 0

1880 4720 0 0

5520 3 0

Physical properties (oven-aged for 14 days a t 250° F.) Tensile, Ib./sq. in. Ultimate elongation, Yo

Samples are 2 inch X 1 inch X 0.076 inch blocks.

V Y X W , grams Basic lead carbonate, grams Stearic acid, gram8 Perbunan 35XS 90, grams Dioctyl phthalate Heat volatility, % '

3

-0.10 -0.06 -13.0 -11.2

Sample A-1755-1 100 3 1.6

2

Physical properties (oven-aged for 7.days a t 250" F.) Tensile, Ib./sq. in. 4280 3190 2230 Ultimate elongation, % 35 60 20

+9.5

2900 140 87

1

,

Physical properties (unaged) Tensile, lb./sq. in. Ultimate elongation, 70 Shore durometer hardness Crescent tear a t room t e m p . , lb./in.

-

-6.0 -8.6

2910 150 89

Formula, parts by wt. VYXW Basic lead carbonate Stearic acid Perbunan 3 5 S S 90 Dioctyl phthalate

....

25 25 16.2 16.2 32.4

-0.15 -0.16

Stock KO.

ties when held for 7 days at 212" F. For improved heat stability, the rubber portion should be protected with 2 parts of an antioxidant such as Deenax (Enjay Co.), PDA (Bensh Engineering Co.), or Stabelite (C. P. Hall). LIGHTAGING. In the light aging study 6 X 6 X 0.075 inch pressed slabs were placed in the Fadeometer (ultraviolet light) a t 125 O F. Results are recorded in Table IX. Observations indicate that the blends treated with Stabelan A (Stabelan Chemical Company) show less color change than the Vinylite tvpe compounds stabilized with lead carbonate and V-1-3 iAdvance and Chemical In fact, stock shows no change in color after 175 hours in the Fadeometer, and stock 3 shows only slight change in color. After the 175-hour test stocks 3 and 6 were stiff. like all the other Perbunan-Vinvlite aged compounds. However, the Fadeometer-aged blends-that contained Stabelan A could be bent 180" a t room temperature without cracking. A number of light aging studies indicated that the best compounds are formed when the mill mixing time is greater than 4 minutes a t 280" F. and the amount of Perbunan is held at about 12.5 to 50 parts on the VYNW.

TABLE1'111.

STABILIZED 35XS 90-VYNW BLENDS

PHYsIC.4L PROPERTIES O F

Stock KO. 1 Formula, parts by w t . VYNV 100 V-l-Xa 3 Basic lead carbonate Stabelan Ab .. Perbunan 35K-S 90 , . Dioctyl phthalate 50 Physical properties (unaged) Tensile, Ib /sq. in. 3070 hIodulus a t 100'70, lb./sq. in. 1670 280 Ultimate elongation, % Shore durometer hardness 85 Physical properties (oven-aged for 3 days a t 250' F.) 1790 Tensile lb./sq. in. hlodu1;s a t loo%,, Ib./sq. in. 1680 140 Ultimate elongation, % Shore durometer hardness 80

..

PERBUNAX

2

3

4

5

6

7

8

100

100

100

100

100

100

100

..

.. ..

3

50

.. ..

3

3

. .50

3190 3240 1870 2180 250 290 84 87 1870 1760 160 62

..

, .

..

50

.,

3130 3130 240 96

1780 2400 1710 .. 110 50 78 59

Physical properties (oven-aged for 6 days a t 250' I?.) Tensile, Ib./sq. in. 4080 4060 4210 4530 Modulus a t loo%',, Ib./sq. in. 4210 ,. Ultimate elongation, 70 '45 '20 100 20 Shore durometer hardness 81 84 89 92 Product of Advance Solvents a n d Chemical Corporation. b Product of Stabelan Chemical Company.

3

,.

50

..

.. ..

3 50

..

..

..

.3 . 50 . . 60 3

60

60

2990 3260 1930 1880 2990 3120 650 740 180 150 370 380 95 94 68 71 2280

2580

70 89

70

..

4320

.,

40 97

..

83

1100

..

80 82

900

..

90 76

3950 2380 3160 ,,

10

92

..

60 90

.60 . 91

November 1947

INDUSTRIAL AND ENGINEERING CHEMISTRY

1451

~~

TABLE IX. LIGHTAGINGSTUDY ON VYNW BLESDS Stock N o . Formula, parts by wt. TYNK V-1-Ii Basic lead carbonate Stabelan A Perbunan 3 5 X S 90 Dioctyl phthalate Fadeometer exposure 100 hours 178 houra

2

1 100 3 ,

,

,

...

...

50

100

...

3'

..... ..... 50

Light

Brown

Brown

Dark brown Bi spotted

3

4

100

100 3

..... ... 3' ..... 50

S o change in color Slight change in color

...

, . .

50

...

5

7

8

100

100

6

100

100

.....

... 3 ....

... 3 ....

..... 3

50

50

50 50

.....

. I . .

Brom-n

Brown

Dark brown

Brown t o black

N o change in color S o change in color

Brown Brown

0

.

...

3 50 50

Light yellow Yellow

raised. For example, the 5-40 blend had a tensile of 17130pounds per square inch, whereas the S-GO blend (stock 4) had a tensile of 1960 pounds per square inch. Also, as the S number 0of the polymer was decreased the low temperaL* ture brittle point was lowered. The per cent -10 u elongation t o break was increased as the styrene c a -20 content of the copolymer was decreased. These a data were expected, as the low styrene copolyI IY - 30 mers are more rubberlike, while the high Spolymers are more resinlike. All of the blends listed in Table X had good crescent tear values a t room temperature. This test indicated that the S-polymer-Perbunan-VYNW mixtures were compatible. Some of the advantages obtained by using S-polymers in the Perbunan 35KS-VYNW blends are improved processing properties and im20 25 30 35 40 45 50 55 TOTAL PLASTICIZER CONCENTRATION (PERBUNAN t DOPI, WEIGHT X proved oven aging properties. To improve the low temperature brittle point for the S-40 polymer-Perbunan 35NS-VYNW Fieure 5 . B r i t t l e TemDerature P l o t t e d aeainst Plasticizer blends, some dioctyl phthalate was compounded C o n c e n t r a t i o n in VYS@ into the systemon arubbermillat280"F. Results are recorded in Table XI. These data shoiv that RESULTS ON S-POLYMER-PERBUNAN-VYNW B L E 3 D S a substantial reduction in brittle point was obtained when dioctyl phthalate was used. However, the results on stock 1 showed I n many experiments it was observed that mixtures of Sthat, if the amount of S-40 polymer was held loiv-that is, 10 polymer and VYSW were extremely difficult to obtain. I n fact, in a number of cases incompatibility Kas recorded unless special _______ techniques were employed. These involved high temperatures and extremes in mastication, and even thencompletehomogeneity TABLEX. S-POLYMERS I N PERBUSAN 3 5 x 8 90-VYXK BLEKDS was not achieved. Stock No. 1 2 3 4 I t was found that Perbunan acted as an efficient plasticizer for Formula, parts b y wt. 9-40 VYKW. I n other previous experiments it was also observed .... 50 ... S-80 ... 50 .... ... that Perbunan was completely compatible with the S-polymers. S-60 50 VYNW lii' 100' I00 100 These investigations revealed that blends of Perbunan-S-polymer Perbunan 3 5 X S 90 50 50 50 50 Basic lead carbonate could be calendered at 225 ' F. to produce self-supported films or 3 3 3 3 Stearic acid 1.5 1.5 1.5 1.5 extruded to give satisfactory tubing and insulation. The conS-resin in blend, % 24.4 0 24.4 24.4 centration of S-polymer could vary over the range 25 to 759& 32 4 24 4 Perbunan 35NS 90 in blend, % 24.4 24.4 Total plasticizer in blend, 7a 32.4 48.8 48.8 48.8 This mutual compatibility suggested a means of securing homoPhysical properties (unaged) geneous blends of VTSK and S-polymers. Therefore, a resin Tensile, Ib./sq in. 2910 li60 1950 1960 Ultimate eloneation. % 290 composition having unique properties might be expected, since 190 li0 80 Shore durometer hardness 94 93 95 96 the good qualities of V T S W and S-polymers might compleBrittle temperature, O F . -40 $40 +70 +80 Crescent tear a t room temp., ment each other. lb./in. 480 420 495 460 Extrusion a t 220' F.* For this nork the S-polymer n a s compounded in the PerInches/rnin. ( a ) \I Couldn't 70 68.5 67.0 bunan a t 220" F. on a rubber mill. The mixture had good procGrams/min. ( b ) extrude 100 93.6, 98 8 Swell index @ ) / ( a ) 1.43 1.37 1.48 essing properties on the mill. The S-polymer-Perbunan mixture Appearance Smooth Smooth Smooth was added to V l N R on a mill a t 280-290" F. Total mixing Physical properties (oven-aged for time for the S-polymer-Perbunan-\7\-SW mixture )vas 15 min3 days a t 250° F.) 1870 2240 2480 29.50 Tensile, lb./sq. in. utes. 120 A0 Ultimate elongation, 9 i 160 140 Shore durometer hardness 62 85 80 8: Table X lists results on S-polymer-Pel bunan 35SS-VYSK Physical properties (oven-aged for blends. The concentration of Perbunan 35SS was held a t 50 6 days a t 250° F.) 2520 2860 4060 2160 Tensile, lb./sq in parts based on the T'YSK, while the S-polymer concentration Ultimate elongation, Yo 20 120 110 40 was held at 50 parts on the T'TSW. K i t h an S-polymer con84 80 95 88 Shore durometer hardness centration of 50 parts on the V T S K the tensile strength was in* 80 r.p.m., 0.4-inch die b y 0.3-inch pin. creased as the S number, or striene content, of the resin mas IO

Y

.,

~

~~~~

'

i

~

INDUSTRIAL AND ENGINEERING CHEMISTRY

1452

TABLE

Stock So Formula, p a r t s b y n t S-40

TYxm-

Perbunan 3 5 S S 90 Basic lead carbonate Stearic acid Dioctyl phthalate Observations Physical properties (unaged) Tensile, lb./sq. in. Ultimate elongation, % Shore durometer hardness Specific gravity Brittle temperature, O F. Crescenr tear a t room temp., Ib./in Extrusion a t 220O F.* Inches/min. l a ) Grams./min. ( b ! Swell index ( b ) ! ( a ) Appearance Physical properties (oven-aged for 3 d a y s a t 250' F.) Tensile, Ib./sq. in. I-ltimate elongation, Fc Shore durometer hardness Physical properties (oven-aged f o r 6 days a t 2503 F , i Tensile, ib.'sq. in. Ultimate elongation, wc Shore durometer hardnees * 80 r . p . m . , 0.4-inch die b y 0.3-inch pin

...

XI. PERBUXAN-\'\*~T$~ S-40 R L E S D ~ 5

6

7

2D

25

100 50

100 50

50 100 50

50 100 50

1.5 25 blight odor, 'light rack

1

2

3

4

10

25 100 50 3 1.5

30 100 50

100 50 3 1.5

S o odor, no surface tack

2490 140 95

1.222 - 30 560

Yo odor, no

surface tack

2

S o odor, n o surface tack

S o odor, no surface tack

Slight odor, slight t a c k

1760 190 93

1710 310 88 1 171

1260 320 87 1.139 - 10

2010 190 94 1.222 20 505

2

f40 420

- 20 280

1330 400 71 1.142 - 30 170

56 77 4 1 38 Smooth

61 81 1.33 Smooth

100 1.19 Ern oo t h

1080

1290

.....

+

123 1.98 Smooth

Smooth

2960 50 80

2370 130 90

2210 1-10 85

1520 130

3360 20 81

1890 120 92

2 1c,o

2090

52.5 80 8 1.54

120 80

parts on tlic I-\-S\T-no dioctyl phthalatv \va,< r i y u i r d t o obtain good Ion teinpcrature properties. Once again th(3 i.csu1ts on extrusion at 220" F. shon-rd that the S-40 polynirr actctl as a processing aid for thc Perbunan-VYSTV blends 01' thii PerhurlanVTS\V-djoctyl phthalate blends. As thc amount of S-40polymer was increastbd in the blend, the extrusion ratc as improved and the sv--elling index v a s reduced. The S-40 polynicir-Perbunan-VTSTV-dioctyl phthalate blends eshibitcti inttwsting aging properties when held a t 250" F. in an air OVCII. For example, in the 6-day aging test, the Perbunan-VI-STT tilcnti s h o w d a short elongation to break, whereas the S-polymerPerbunan 35XS-TTSK type blends retained to a grcat rstcnt their original elongation.

3

3 1.0

.....

.....

70 100 1 43 Eniooth

62

Vol. 39, No. 11

85

110 80

3 1 5 50 Slight odor, .light tack 800.

50 71 1.125 - 20 110

220

84

72 84 1 17 Smootb

'

860

140 80

140 85

30

1320 120 79

1930 100 84

1490 30

75

76

.ACKNOWLEDGRIENT

The advice, c.ricour:igc,nient, and assistance of I,. T3. Turricr, 13. 11. V:tnclci.liilt, \T7, ,J, Snarlis, and E. ?;. Cunninglinni during thc c o i i r ~ rof this work are greatly appreciated. LITERATURE CITED

(1) I.'uo~s.I!.

lI.,.I. - 1 ~ 1 C'hem. . SOC..63, 369-78 (1941). ( 2 ) Hendermii. D. I?.. IT,9 . Patent 2,3300,353 (Seot. 2 5 . 1943) (3) Kcnney. It. P.. Jforlcrn Plastics, 23, 106-7 (Sept. 1 9 4 0 ) . (1) lloulton. 11. 8.. Iliid.. 23, 117-20 (Oct. 1 9 1 6 ) . (5) Plotterberk, 0. r., arid Young. D. IT,,Am. Pairif 6.. 29, Yo. 5.4, 16 (1944).

(6) Sn1yei.s. \V.11.. U. P.Patent 2.274.749 ( 1 9 4 2 ) . (7) Vinkelmann, H. A , , India R i ~ h b T o~d d , 113, 799-804 (1946) R E C E I V EM D a y 0 , 1947.

EXPRESSED PEACH KERNEL OIL W. A. BUSH

.iSD

B. J. C.4G.41

3135 East 2 6 t h S t r e e t , Los iingeles 23, Culif.

U

STIL a little oyer two decades ago the so-called peach kerncl oil of coninierce (sometimes also called "oil almonds P.K.")

was obtained from apricot kernels. I n 1023, at the request of agents of the United States Department of Agriculture, the oil expressed from domestic apricot kernels \vas correctl?- named "apricot kcrnel oil" and is commercially kno1v-u as such today. Peach pits arc more difficult to dry and to crack than apricot pits. The percentage of dry kernels obtained from peach pits is, in most cultural varieties, only 9 to 11 of the whole dried pits. Frequently the percentage is even lower. This is less than half the yield from apricot pits, which is 20 to 33C, of the kcrriels, according to variety. For these reasons t r u c peach k ( ~ n o loil had seldom, if ever, been manufactured in commercial quantities. Scarcity of edible and pharmaceutical oils and an iniprovcd commercial outlet for the by-product shells have resulted in the possibility of an oil pressing operation on a commercial scalc. of In this operation 21,400 kg. of peach kernols (~ontaining42.3?~ oil) were pressed t o produce peach kernel oil and oil-cake meal. The crude oil has a yclloiv color and a strong flavor and odor of

I ) c l l x a l d t ~ h y d c c . ~ : ~ r ~ h ~ (It~ rwas i n . e a d y improved in flavor and lightctnc~din color by simple treatment r i t h an activated niontmorillonite. Thc characteristics of the treated oil are: Specific gravity, 1:' C. Refractive index, 2 5 . S C C. Saponification \ - d u e I-nsaponifiable matter, 7 Iodine number (Il-ijs) .kcid \.slue Titer, 0-c: Color i l o v i b o n d ) Flavor

0.9224 1.46990 191 4 0.65 98.1 0.67 11

25 yellow, 3 red Bland, mildly almondlike

The titer is 2 lo\vcsr t h i n the l o i n s t of the range given by Jamieson ( 2 ) . H o ~ - ( ~ vitL is ~ I\\-ithin ., the 5-13' C. range given by Hilditch (1). LITERATURE CITED

(1) H i l d i t r h , T. P., "Ilidustrial Chemistry of F a t s a n d \Vases." 11. 119, New York, D. \-anNostrand Go., 1 9 4 1 . ( 2 ) J a m i e s o n , G. 9.."1-egetable F a t s and Oils," 2nd ed., 1). 173. Xew York, R e i n h o l d Puh. Corp., 1943. RrcEIVEo October 4. 1946