T H E THERIIOELAISTIC EFFECT IPIJ CELLITLOSE ESTER FIL1\IS1 BY J. G. MCSALLY AND S. E. SHEPPARD
I n general, metals, as well as many other materials, are cooled, i.e., absorb heat, when stretched.* The relationship of the elastic and thermal properties of such normal materials may be summed up in the statements3 that with increasing temperature, (a) the modulus of elasticity decreases, (b) the elasticity number or deformation increases, L e . , the cross-sectional alteration increases more rapidly than the elongation; however, (c) the volume alteration decreases. This behavior indicates a relation of the elastic properties to the coefficient of thermal expansion, in fact this coefficient depends upon the stress on the material in question. From thermodynamic reasoning it follows that the temperature coefficients of thermal expansion and of elastic deformation (or of the modulus of elasticity) must have opposite signs. Accordingly, with normal materials, e.g., metals, the thermal expansion coefficient increases with increasing stress, while the modulus of stretch (Young’s modulus) decreases with rising temperature. Apparently quite contradictory is the behavior of rubber. Early observations by G ~ u g h rediscovered ,~ by Page5 and Joule2 showed t.hat rubber is warmed, or develops heat, on stretching. In agreement with the previously sketched reciprocal relations of the thermal and elastic properties, and more generally, with the Braun-LeChatelier rule, Kelvin6 predicted that stretched rubber would contract if heated; this was experimentally confirmed by Joule. Since then a large number of investigations of the Joule effect with rubber have been made, and numerous explanations offered. A review of these researches has been made by Whitby.’ The phenomena are complicated, and point to transitions between metal-like and rubber-like solids. The main results for rubber may be summarized as follows: ( I ) Some samples of rubber show an initial cooling on stretching followed by a rise in temperature.* Other experimenters find only the heating e f f e ~ t .The ~ rate of extension has a marked effect on the thermal change: a high rate causes the disappearance of the initial cooling and an increase in the amount of heating a t any extension.1° At a given rate of elongation, a critical temperature exists above which the negative (cooling) effect is not a p ~ a r e n t . ~ Communication No. 44j from the Kodak Research Laboratories. Joule: Proc. Roy. Soc., London, 8, 335 (1857); Phil. Mag., 14,226 (185;). 3 Cf. Auerbach: Winkelmann’s “Handbuch der Physik,” I ( I ) , 584 (1908). 4 Mem. Proc. Manchester Lit. Phil. Soc., 1 ( z ) , 2 2 8 (18oj);Nicholson’s J., 13,30j(1886). 6 Silliman’s J., (z), 4, 341 (1847). 6Cf. Joule: Proc. Roy. Soc., 8,335 (1857); Phil. Mag., 14,226 (1857). “‘Plantation Rubber and the Testing of Rubber,” 453 (1920). 8 Villari: Ann. Physik, 144 274 (1872). 9 Schwarts and Kemp: Mem. Proc. Manchester Lit. Phil. SOC., 55 (IZ),g (191I). ‘OChauveaux: Compt. rend., 128. 388, 479 (1899). 1
THERMOELASTIC EFFECT IN CELLULOSE ESTER FILMS
IO1
Rubber under low stresses expands longitudinally on heating but (2) contracts when heated under a high stress.“ The contraction caused by an increase in temperature is greater a t a low temperature than a t a high temperature and if the temperature is raised sufficiently, no contraction takes place. The temperature a t which the change of sign occurs is higher the greater the load.12 It may be mentioned that muscle fibers show many points of resemblance to rubber on thermoelastic relations,ls but, so far as we are aware, no investigation of these has been made with synthetic organic colloids. Investigations on the birefringence of cellulose ester films under stress14as well as the change in X-ray diagram of these materials under stress15show them to have certain similarities to rubber in structure and behavior. On the other hand, it has been pointed out that their elastic behavior in some respects approaches that of metals more nearly than that of rubber.I6 We have made a study of the thermoelastic relations of cellulose nitrate and cellulose acetate films, covering both the heat changes taking place when the films are stretched, and measurement of the coefficient of thermal expansion a t different temperatures and stresses.
I. Heat Changes of Cellulose Ester Films when stretched Experimental Method Test pieces of cellulose acetate and nitrate films were placed in a dynamometer that made a record of the stress-strain curve of the material. A multiple junction Moll thermopile was clamped to the lower jaw of the dynamometer in such a manner that the opening of the instrument was kept in contact with the flat surface of the film during the stretching. The leads from the thermocouple were attached to a Leeds and Northrup high sensitivity galvanometer, the deflections of which were read on a scale I meter distant while the film was stretched. By noting the time a t which the stress-strain data were recorded by the dynamometer and the time at which the galvanometer was read, the thermal effect during any part of the stress-strain curve could be determined. All test pieces were I 5 cm long, I cm wide, and very close to 0.014cm thick. Experimental Results Cellulose Sitrate: Figure I shows the stress-strain curve for a sample of cellulose nitrate a t 18.6“C and R.H. = 5 5 per cent. The three curves are check runs and indicate the degree of reproducibility of the experiments.
The numbers along the curves give the scale deflections in millimeters of the Van Bjerken: Ann. Physik, 43, 817 (1891). Lundal: Ann. Physik, 66, 741 (1898). l 3 E n elmann “Ueber den Ursprung der Muskelkraft,” 2nd Ed. (1893); McCallum: J. Biol. bhem., 1’4, 96 (1913). l4 McNally and Sheppard: J. Phys. Chem., 34, 165 (1930). l5 Trillat: J. phys. radium, 10, 370 (1929). Sheppard and Carver: J. Phys. Chem., 29, 1244 (1925). l1 l2
I02
J.
Q. RlCNALLY AND S.
E. SWEPPARD
galvanometer at the corresponding elongation and stress. It will be seen that the cellulose nitrate film cools o n stretching u p to the uield point, when it starts to warm u p and continues giving off heat until i t breaks. The evolution of heat is greater than the absorption during the cooling period. This film was weakly biaxial and the test piece was cut in the direction of the residual extension, as in all of the remaining experiments on biaxial films.''
FIG.I
FIG.2
Cellulose Acetate. Figure 2a shows the thermal changes observed on stretching a biaxial cellulose acetate film a t 16.7" and 53 per cent R.H. The curves obtained with a uniaxial plate coated acetate film were very similar (Fig. 2b) and both are nearly identical with the nitrate film. Elongation at Constant Rate As mentioned above the negative heat effect changed to a positive one a t the yield point. Whether this change was caused by a difference in the reFor a method of determining micellar orientation in films see McNally and Sheppard:
J. Phys. Chem., 34, 165 (1930).
THERMOELASTIC EFFECT IN CELLULOSE ESTER FILMS
103
action of the internal structure of the film to stress a t this point, or whether the inversion was simply connected with the rate of extension of the film, could not be determined. The following experiment was therefore carried out in which the film was stretched a t the constant rate of 0.13 cm per second until the film broke. The data from this experiment are presented in Table I. 0 is the scale deflection of the galvanometer. The change in sign of the thermal effect came a t an elongation of about 7 per cent, which checks very closely with the extension a t the yield point for this film (see Fig. 2 c ) . We conclude, then, that the increased rate of extension after the yield point does not cause the inversion of the thermal effect. The thermoelastic relations of another mechanically coated film are given in Fig. PC. The curve is similar to the former. The measurements were made a t 18.6' and 55 per cent R.H. Change in Temperature Figure 2d is a duplicate of 2c carried out a t 22.4OC. This is the greatest variation in temperature it was possible to obtain under our present experimental conditions but it appears that this variation causes little if any change in the thermoelastic relation. TABLE I The Thermal Effect on Stretching Cellulose Nitrate Film at a Constant Rate of 0.13 cm/sec a t 18.4'C, 50 per cent R.H. Time sec
L cm
AL cm
0
1 5 00
0.0
0 0
0.13 0.26
o 86
I
1 5 . I3
2
15.26
3
15.39 I5 4 2 15.65 15.78 15.91 16.04 16.17 16.30
4
5 6
7 8 9 IO
I1 I2
16.43 1 6 .j 6
'3 I4
16.79 16.92
I5
16
I 7 .os 17.18
I7 18
'7.31 17.44
IOO
AL/L,
1 72
0.39
2.58
0.52
3.44
0.65 0.78 0.91
4.30 5.16 6.02 6.88
I .04 1.17 I .30
1.43 .56
7.74 8.60 9.26
I
10.12
1.79 .92 2.05 2.18 2.31
10.98 11.84 12.70
I
2.44
13.56 14.42 15.28
e 0
-0. j
104
J. G . MCNALLY AND 5. E. SHEPPARD
Coagulated Cellulose Nitrate Films Dried under Varying Tension Figure ze indicates the heat effect of stretching a film prepared by setting a collodion solution in water as in preparing membranes and stretching the coagulated film I O per cent during curing. The period of plastic flow is absent and the heat evolution that accompanies it is also missing. The data from a film prepared in the same way but allowed to shrink I O per cent on curing are given in Fig. zf, and it is essentially the same as the air dried film. Both films were biaxial, the former very strongly so and the latter~veryweakly.
FIG.3
Coagulated Cellulose Nitrate Films with High Volatile Content In Fig. 3 the stress-strain curves are given for a number of coagulated films. A was stretched while still containing about 50 per cent of volatile material, b about 30 per cent; c about 15 per cent, and d about I O per cent. While the shapes of these stress-strain curves are very different, the thermal effect is still the same-cooling at low elongations and heating at higher elongations. Conclusions as to Thermoelastic Effect ( I ) It appears that a t ordinary temperatures both cellulose nitrate and cellulose acetate films cool when stretched to small elongations. At higher strains (deformations) an inversion in the thermal effect takes place, and heat is evolved. This result holds both for films formed by air drying (solvent evaporation) and by coagulation (solvent extraction). (2) If the film is stretched on drying sufficiently to become strongly biaxial, this secondary heating effect disappears. (3) The thermoelastic properties of coagulated films are independent of their content of volatile solvent. (4) The thermoelastic effect is the same at constant rate of elongation as under the loading conditions with a dynamometer. From these results it would appear that cellulose nitrate and acetate films should show lower resistanee to a small strain (elongation) but increased
I 06
J. G . MCNALLY AND S. E . SHEPPARD
The temperature of the test piece was controlled by the use of the cylindrical cooling jacket J and the nichrome wire heating coil N the cork layer I serving as an insulator. The test piece was brought to the lower limit of the temperature interval to be investigated by circulating a cooling liquid through J. Wherever possible, this was done by circulating water from a constant temperature bsth by means of a centrifugal pump, the liquid entering through O1 and being forced out through 0 2 . During the experiments that were carried out a t low temperatures, the circulating liquid was ethyl alcohol and
FIG.qh
. 0,
cooling was effected by passing the liquid through a copper coil immersed in a carbon dioxide-ether eutectic mixture. The temperature of the test piece was raised by passing an electric current through the nichrome coil N which was wound around the glass tubes GIG*. These tubes were attached to the inside of the guide rails at either end. The rate of heating could be controlled by a potentiometer in the heating circuit. In all the experiments described in this paper the potentiometer was so set that the temperature of the film was raised from I j to 45' in 45 seconds. The cooling took somewhat longer, as it required about three minutes for the film to return to its original temperature; but during most of this time the film was only a few degrees above I jD, so the rate of flow was low. The temperature of the film being studied was measured by the five-element copper-constantan thermel T the junctions of which were placed inside the heating coil and were about 0.I mm away from the film. The thermocouple leads were carried through the glass tubes GIG2 and out of the cylinder through a hole in the base. The ends of the thermel were connected to a Leeds and Sorthrup potentiometer temperature indicat-
THERMOELASTIC EFFECT IN CELLULOSE ESTER FILMS
105
resistance to a large one as the temperature is raised. But if the material is analogous to rubber, the rate of heating and the rate of loading would determine whether or not the films would show increased or decreased resistance to stretch a t higher temperatures.
11. The Thermal Expansion of Cellulose Nitrate T o fill out our knowledge of the thermoelastic properties of cellulose esters, a study was made of the thermal expansion of cellulose nitrate. It is well known that several crystals-silver iodide and calcspar for e x a m p l e h a v e negative coefficients of thermal expansion along certain crystallographic axes. The phenomenon has also been met with in the case of strained elastic colloids, notably rubber where it has been the subject of a large number of extensive investigations. No data existed on the thermal coefficient of expansion of any of the cellulose esters so the experiments to be described were undertaken to supply this need. Apparatus The thermal coefficient of expansion of crystals and'metals is a well-defined property of the material that depends on the mean distance between the vibrational centers of the component atoms. I n the case of organophilic colloidal materials, however, the measurement of expansion coefficients is complicated by the property which the material possesses of flowing a t very low stresses. Further, the rate of flow is increased by a rise of temperature so that the elongation observed on raising the temperature of a test piece is partly caused by thermal expansion and partly by plastic flow. I n constructing an apparatus to measure the thermal expansion coefficient of organic films the rate of heating of the film should be rapid and it should be possible to measure the temperature of the film accurately at any time during the experiment. Further, dimensional changes of the test piece caused by adsorption and desorption of water or solvent vapors by the film should be eliminated. Since it would be extremely difficult to keep the test piece continuously in an atmosphere of constant humidity while the temperature was changing rapidly, it was necessary to carry out all experiments a t o per cent relative humidity, i.e., with all solvent and water vapor removed from the film. A diagram of the apparatus used is shown in Fig. 4, and Fig. 4a gives an enlarged view of the arrangement of the interior. The test piece, F, is clamped between the two clamps C1C2,the bottom clamp being fixed and the top one being free to slide up and down the guide rails RIRz which are rigidly secured to the heavy base plate B, of the apparatus. Tension is applied to the film by the weights, W, acting over the frictionless pulley P and through the metal rod A. The elongations were measured by means of the traveling microscope M which was fitted with an x7.5 ocular and a 4 mm objective. The microscope was focused on the micrometer slide S the lines of which were ruled 100 to the millimeter, and was illuminated by a microscope lamp not shown in the diagram. For small rapid changes in the length of the test piece it was found convenient to observe the movement of the scale, leaving the microscope in a fixed position.
THERMOELASTIC EFFECT IN CELLULOSE ESTER FILMS
107
ing instrument, and alternate junctions were kept in a tube immersed in an ice-water bath. This temperature measuring system was calibrated against a Bureau of Standards pentane thermometer. The test piece was thoroughly evacuated at room temperature before being placed in the apparatus. I t was then kept in an atmosphere of o per cent R.H. for fifteen hours before expansion measurements were attempted. Air was passed through two sulfuric acid scrubbing towers and into the apparatus at D. A constant head of dry air was thus maintained inside the apparatus which prevented the condensation of moisture at low temperatures. Finally, the whole apparatus was mounted on a spring suspension hung from the roof rafters of the building to eliminate errors caused by vibration. Measurements were read on scales to 0.01mm and estimated to 0.001mm so that a change in length of o.oooj per cent on a 20 ern test piece could be recorded. Materials All of the experiments described here were carried out on a single sample of cellulose nitrate film. The film was slightly biaxiaP and the double refraction measurements made on the film are given in Table 11.
TABLEI1 Double Refraction of Cellulose Nitrate Test Sample d = 0.15mm B Axis
C Axis
e
6
0
+S
IO
+2
20
s/d
0
+ '3 + I3
0
IO
0
0
20
-I 2
30
40
50 60
- 24
-33 - 80 - 160
-32
-210
60
30
-5
40 50
6
+5 +j
$7
+ I3
++30 +
6/d
+33 f33 46 +87 '33
+
20
+ +
40
+266
200
Test pieces were cut from this film in the direction of coating so that tension was applied along the direction of stretch. The test pieces were cut exactly 0.50 cm wide by means of a slitting tool made with the two knife edges 0.50 cm apart. As mentioned above, the film was 0.1j mm thick and the original length of the unstrained test pieces between thegrips was z r.zocm.
Experimental Results ( I ) The Thermal Expansion of Cellulose Nztrate Fzlmjrom 16 to S5".
A test piece of cellulose nitrate film was prepared and placed in the apparatus as described above. After the film had been in an atmosphere of dry air for fifteen hours, a tension of zoo grams (stress = 0.26 Kg/mm2) was applied and the test piece was alternately heated to 40' and cooled until the retraction curve showed no hysteresis lag. This reversible effect is shown at
108
J. G . MCNALLY AND
S. E. SHEPPARD
the lowest part of the curve in Figs. 5-7. The film was then judged to be dry and free from volatile solvents. The load was increased to 1000 grams (stress = 1.33 Kg/mm2),when the elongation measured increased by 0 . 2 2 per cent of the original length. As indicated by Figs. 5 - 7 , heating and cooling curves show that at this stress, the film support is not perfectly elastic. The cooling curve maintains a very appreciable lag under the heating curve. As the extension and retraction cycle is repeated the difference between the elongation and retraction curves decreases until after the fifth cycle the two
0
FIG.j
curves practically coincide. If, now, the load be increased to 1600 grams (2.13 Kg/mm2) the initial hysteresis lag becomes more marked than was the case a t lower stress and the form of the initial extension curve becomes concave with respect to the temperature ordinate. The curves again coincide after the cycle of extension and retraction has been repeated several times. As the tension on the film support is increased, a progressive series of changes takes place in the thermal expansion curves. Referring again to Figs. 5-7, it will be seen that the initial heating curve remains concave with respect to the temperature axis but the successive heating curves become strongly convex in the region where the stress varies from 3.19 to 5.05 Kg/mm2. At the same time the retraction curves become markedly convex so that over a large portion of this region of stress, the two sets of curves intersect each other. Above a stress of 2 . I Kg/mmz, the divergence between the final lengths reached after extension and retraction does not become appreciably less on repeating the cycle. Finally, at a stress of 7.98 Kg/mm2, the rate of plastic flow of the material was so great that it became impossible to measure temperature effects with any accuracy with the present type of apparatus.
THERMOELASTIC EFFECT I N CELLULOSE ESTER FILMS
IO9
The coefficient of thermal expansion of the support is a poorly defined quantity as it depends on the stress acting on the film and the rate a t which the heating and cooling operations are carried out. Under the conditions of our experiments the latter factor may be neglected because the error in a single determination attributable to plastic flow is negligible. While the curves are not linear, the coefficient depends on temperature interval over which it is measured and it always depends on whether the extension or re-
FIG.6
traction of the film is used for the computation. An average value for the thermal coefficient of expansion for film support may be defined by the equation: c y =
L1 - i(LOfL2) ( L o ) (TI-- To)
where cy is coefficient of linear expansion, Lo is the length of the test piece before expansion a t temperature To; LI is the length to which the filmexpanded at the higher temperature, TI, and LZis the length to which the test strip contracted a t temperature To. The slopes from which the values of LY were calculated are shown by dotted lines in Figs. 5 and 6. Table I11 shows the results of such calculations at different stresses.
J. G . MCNALLY AND S. E. SHEPPARD
I10
TABLE 111 The Linear Coefficient of Thermal Expansion for Cellulose Kitrate Film between 1 5 and 35’ Stress-Kg/mm2
a X
10-5
33
4 38
2 13 3 19
3 43
I
3 00 2 43
3 86 4 49 5 05
2
29
2
11
THE UNLLR DlnLN%ONLL CULNGES C&USCV
W ~ ~ P E R L T U R L ~ V L R I L T I OIN N ICELLULOSENITRATC FILM SUPPORT UNDER VIFFEREN’I
-
43
TEMPERATURE
FIG.7
The coefficient decreases progressively as the stress increases but the rate of decrease as shown by Fig. 8 decreases as the stress increases. The influence of the previous treatment of the film on its coefficient of thermal expansion is shown in Figs. 5 and 6 by the decrease in the coefficient caused by successive elongations and retractions carried out a t a constant stress. For example, a t a stress of 1.33 Kg/mm2, a equals 4.38 X IO-^ on the first extension-contraction cycle and 4.27 x IO+ on the fifth. The stresses on the test pieces of the size used throughout these experiments are given on the next page, together with the corresponding load.
THERMOELASTIC EFFECT IN CELLULOSE ESTER FILMS
111
TABLE IV Load-Kg.
Load-Kg.
Stress Kg/mm2
0 . 2
0.266
2.9
0.4 I .o
0.52
3.0 3.3
I
.6
2 .o
2.4
1.33
* ,33
3.8 6.0
2.86 3.19
Stress Kg/mm2
3.85 3.99 4.39
5 .OS 7.98
FIG.8 The coefficient of thermal expansion of cellulose nitrate film su rt at different stresses. Temperature interval from + I S to +~SOY
The Thermal Expansion of Cellulose Nitrate from - 10 to -36". The above thermoelastic studies led to the conclusion that under the proper conditions, cellulose ester films should contract when heated. The flat portions of the extension curves in Figs. 5 and 6 are probably the resultant of two opposing tendencies of the film to change its length. The first is a plastic flow tending to increase the length of the sample and the second is an elastic contraction. When the two are equal, the net resultant observed is zero. If the above explanation of the flat portions of the curves were correct, it should be true that at low temperatures, where the rate of plastic flow was decreased, a resultant contraction of film support could be observable when the temperature of the test sample is raised. Figures 9 and I O show the thermal extension-contraction curves of cellulose nitrate under varying stresses over the temperature range from - I O to -35O. At low tensions while the film has undergone but little strain and is sensibly isotropic with respect to the lengthwise direction, the thermal extension is positive but it has a lower value than at higher temperatures. At a stress of 0.53 Kg/mm2 between -27 and - 12', a = 2 . 5 X IO-^. As the film becomes anisotropic from stretching a t higher stresses, the initial effect of a rapid rise in temperature of the film is to ~ n u a~ contraction e of the film. The negative expansion coefficient is of the >sine order of magnitude as the positive one, being equal to -3.4 X 10-5 a t a (2)
I I2
J. G. MCNALLY AND S . E. SHERPAPD
stress of 1.33 Kg/mm2. The initial contraction of the film support continues up t o a stress of 5.0 Kg/mmz. At higher stresses, plastic flow becomes rapid so that the effect can no longer be observed. In the case of crystals belonging to an irregular system, a usually has very different values in different directions, calcite for example having a = $ 2 5 x IO+ parallel to the optic axis and - j X IO+ perpendicular to the axis. It seems not improbable, then, that the coefficient along and across an anisotropic film may be quite different. The values of Q across certain biaxial films may be many times the values given here.
FIQ. 9 The linear dimensional changes caused by temperature variations in cellulose nitrate fdm support under different stresses. Temperature range from -15" to -35°C. 0 = points observed on heating X = points observed on cooling
Summary and Conclusions Cellulose acetate and nitrate films that have not been subjected to large stresses on drying, cool when extended to small elongations but become warm if the extension is prolonged beyond the yield point of the material. If the structure of the film is altered by drying the film under large stresses, the region of strain corresponding to the exothermic reaction disappears. Coagulated films containing large amounts of solvent showed the same thermal behavior on stretching as the dry film, although the stress-strain relations were totally different. The thermal coefficient of expansion of cellulose nitrate is a poorly defined quantity which depends on the stress on the material, the previous mechanical and thermal history of the sample and the temperature range over which the thermal expanison is measured. At low temperatures and at moderate stresses a negative thermal expansion was observed which is analagous to the Joule effect in rubber.
THERMOELASTIC EFFECT I N CELLULOSE ESTER FILMS
1I3
From this evidence it may be reasoned that the predominating structural alteration taking place in the film while being stretched is different in the different regions of the stress-strain curve. Possibly the cooling effect is associated with an increase in the potential energy of the micellar structure caused by an increase in the mean distance between attraction centers of the component units, this effect predominating a t low strains. The exothermic change may then be evidence of mechanical dissipation of energy by internal
TEMPERATURE
FIG.I O
friction in the film or a further structural change which results in a space lattice arrangement of the cellulose ester molecules and produces a thermal effect akin to a heat of crystallization as has been discussed recently in the case of rubber.I8 At any rate, the existence of the anomalous Joule effect in a dry, solvent-free cellulose ester film proves that the effect is not a priorz evidence of a two-phase structure of the colloid, as has been suggested in the case of rubber.lg It is also inconsistent with Wo. Ostwald's20explanation of 1 8 H o ~ kKolloid-Z., : 37, 19 (1925);Katz: 36, 300 (192j). '9Freundlich and Hauser: Kolloid-Z., 36, I j (1925). Kolloid-Z., 40, j8 (1926).
*O
I I4
J. G . MCNALLY AND
S. E. SHEPPARD
the structural change in rubber on stretching. Ostwald attributes the appearance of a “fiber diagram” to the deformation of a preexisting mesh or network structure in the sheaths of the latex particles. But, the parallel behavior of gelatin and cellulose esters on stretching, in approaching to or developing “fiber diagrams”, makes this hypothesis unnecessary and inadequate, since the gelatin and cellulose ester films may be prepared from solutions containing only amicroscopic particles. And that is also the case with rubber from Feuchter’s D-rubber (or diffused rubber sol). Kodak Research Laboratones, Eastmun Kodak Company, Rochestm, New York.
