THE STUDY OF RELATIONSHIP OF UREA GROUPS IN POLYUREA GREASES & THEIR

PROPERTIES

Vijay Deshmukh

Chetan Pagare

Standard Greases & Specialities Pvt. Ltd.

Mumbai, India

NLGI 85TH Annual MeetingCoeur d’Alene, ID USA

2018

STANDARD GREASES & SPECIALITIES PVT. LTD.,INDIA

- THE LARGEST PRIVATE LABEL GREASE MANUFACTURER IN INDIA WITH A PRODUCTION CAPACITY OF 42,000 MTS PER YEAR.

-THREE GREASE MANUFACTURING PLANTS.

-MOST OF THE REPUTED MNCS ARE CUSTOMERS

-ALL PLANTS ARE ISO 9001:2015,ISO 14001:2015, OHSAS 18001:2007 AND TS 16949: 2009 CERTIFIED.

-MOST MODERN GREASE R&D CENTRE RECOGNISED BY GOVT. OFINDIA.

INTRODUCTION--IN LARGE SCALE PRODUCTION OF POLYUREA GREASES, MAIN CONSTRAINT OF TOXICITY AND HANDLING OF TOXIC RAW MATERIALS

-POLYUREA GREASES HAVE EXCELLENT HIGH TEMPERATURES PROPERTIES,EXCELLENT OXIDATION STABILITY, GOOD WATER RESISTANCE, GOOD CORROSION RESISTANCE AND GOOD FLOW PROPERTIES.

- THESE PROPERTIES MAKE THEM IDEAL CHOICE FOR STEEL PLANT APPLICATIONS.

- ALSO POPULAR FOR AUTOMOTIVE APPLICATIONS.

- MAIN CONSTITUENTS ISOCYNATES AND AMINES.

- POLYUREA CHEMISTRY OFFERS DEVELOPMENT OF POLYUREA GREASES WITH DIVERSE PROPERTIES.

POLYUREA GREASES WITH DIFFERENT NO. OF UREA GROUPS

HYDROGEN BONDING IN POLYUREA GREASE

- MAJOR DRAWBACKS OF POLYUREA GREASES ARE INCOMPATIBILITY WITH OTHER HIGH TEMPERATURE GREASES AND THEIR TENDENCY OFHARDENING ON LONG EXPOSURE TO HIGH TEMPERATURES.

- COMMERCIALLY MOST POPULAR POLYUREA GREASES ARE DIUREAS AND TETRAUREAS.

- POLYUREA GREASES HAVE STRONG HYDROGEN BONDING AMONG UREA MOLECULES RESULTING IN STABLE STRUCTURE.

- FIG 1 SHOWS FTIRS OF ALL POLYUREA GREASES

- POLYUREA GREASES ATTRACTED ATTENTION DUE TO RECENT CRISIS IN AVAILABILITY OF LITHIUM HYDROXIDE AND ITS HIGH PRICE.

FTIR OF POLYUREA GREASESFIG.1

EXPERIMENTAL

-POLYUREA GREASES PREPARED USING ISOCYNATE, AMINES AND MINERAL OIL

-CONVENTIONAL PROCESS USED. REACTION COMPLETION CHECKED BY FTIR

-THICKENER CONTENT MAINTAINED AT AROUND 15.3 %

-STOICHIOMETRIC AMOUNT USED TO MAKE DI UREA,TETRA UREA,HEXA UREA AND OCTA UREA GREASES.

-ALL THE FOUR SAMPLES TESTED AS PER ASTM TEST METHODS

-SHEAR REVERSIBILITY AND HIGH TEMPERATURE HARDENING TESTED BY IN-HOUSE METHODS

Properties Test Method Results

Appearance Visual Bright & clear

Density, gm/cc D 1298 0.882

Kin. Viscosity @ 40˚C, cSt.

D 445 86

Kin. Viscosity @100˚ C D 445 10.1

Flash point,˚ C D 92 246

Pour point,˚ C D 97 0

TABLE 1

BASE OIL CHARACTERISTICS

SHEAR REVERSIBILITY-

-UNWORKED,WORKED 60 STROKES PENETRATION CARRIED OUT.

-AFTER 60 STROKES PENETRATION,THE CUP KEPT AS IT IS AND AFTER 15 MINUTES THE SAMPLE WAS CHECKED FOR PENETRATION. THEN AGAIN AFTER 30 MINUTES PENETRATION WAS CHECKED. AGAIN AFTER 60 MINUTES AND 120 MINUTES PENETRATIONS CHECKED AND REPORTED.

-SIMILARLY,100 K STROKES WERE GIVEN. SAMPLE REMOVED AND AT 25˚C 60 STROKES PENETRATION WAS DETERMINED.

-THE CUP WAS KEPT AS IT IS AND AFTER 15 MINUTES AGAIN PENETRATION WASDETERMINED. AGAIN AFTER 30 MINUTES,60 MINUTES AND 120 MINUTES PENETRATION WAS CHECKED AND REPORTED.

HIGH TEMPERATURE HARDENING TEST-

- UNWORKED PENETRATION WAS DETERMINED AT 25˚C.

- THE CUP WAS KEPT IN OVEN AT 200˚C FOR 2 HRS.

- AFTER 2 HRS. THE CUP WAS REMOVED AND KEPT AT ROOM TEMPERATURE FOR 3 HRS.

- THE UNWORKRD PENETRATION WAS CHECKED AND REPORTED.

- THE PENETRATION AFTER THE TEST INDICATES THE HARDENING TENDENCY OF THE GREASE ON EXPOSURE TO HIGH TEMPERATURES.

RESULTS AND DISCUSSIONS-

CONSISTENCY-

-ALL THE GREASES TESTED FOR UNWORKED,WORKED (60 STROKES) AND WORKED 100 KSTROKES.- THE DIFFERENCE IN 60 STROKES AND 100 K STROKES PENETRATION INDICATES THE

SHEAR STABILITY OF THE GREASES.- THE DIFFERENCE INCREASES WITH INCREASE IN UREA GROUPS.- SHEAR STABILITY DECREASES WITH INCREASE IN UREA GROUPS.

ROLL STABILITY-

-THE PERCENT CHANGE IN PENETRATION INCREASES FROM DIUREA GREASE TO HEXA UREAGREASE. IN OCTA UREA GREASE THE CHANGE IS NOT UNIFORMLY INCREASED.

- THIS DATA SHOWS SIMILAR RESULTS AS FOR THE SHEAR STABILITY BY 100 K STROKES.

Test D 217 Di urea Tetra urea Hexa urea Octa urea

Penetration

Unworked

Worked(x60)

Worked(100K)

Difference

270

287

319

+32

204

256

338

+82

220

263

399

136

254

298

440

142

CONSISTENCYTABLE 2

Test D 1831 Diurea Tetra urea Hexa urea Octa urea

Roll stability

@ room temp.16 hrs,

% change in

penetration 6.6 28.8 34.4 29.8

ROLL STABILITY TEST-

TABLE 3

DROPPING POINT-

-THE DROPPING POINT FOR DIUREA GREASE IS LEAST AND THE DROPPING POINT OF TETRA UREA GREASE IS HIGHEST FOR HEXA UREA AND OCTA UREA THE DROPPING POINT IS ALMOST SIMILAR.

LEAKAGE TENDENCY-

-THE TEST IS CARRIED OUT AT 160˚C. -THE RESULTS INDICATE THAT THE LEAKAGE INCREASES WITH INCREASE IN UREA GROUPS.

OIL SEPARATION --IN ALL THE CASE THE OIL SEPARATION IS VERY LOW.-THE OIL SEPARATION DECREASES WITH INCREASE IN UREA GROUPS.

Tests Diurea Tetra urea Hexa urea Octa urea

Dropping Point, ˚CD 2265

183 270 260 262

DROPPING POINTTABLE 4

Test D 4290 Diurea Tetra urea Hexa urea Octa urea

Oil Leakage, % wt

- 0.83 1.66 3.33

ACCELERATED LEAKAGE TENDENCY TESTTABLE 5

Test D 6184 Diurea Tetra urea Hexa urea Octa urea

Oil separation, % wt

2.62 0.34 Nil Nil

OIL SEPARATIONTABLE 6

SHEAR REVERSIBILITY-

-THE GREASE SOFTENS UNDER SHEARING.AS SOON AS THE SHEARING FORCE IS REMOVED, IT TRIES TO REGAIN ITS CONSISTENCY.

-POLYUREA GREASES ARE KNOWN TO HAVE SHEAR REVERSIBILTY PROPERTY.

-THE SIXTY STROKES DATA INDICATES THAT THE SHEAR REVERSIBILTY PROPERTY DECREASES WITH INCREASE IN UREA GROUPS.

Shear reversibility

Diurea Tetra urea Hexa urea Octa urea

Penetration UnworkedWorked(x60)

274290

208259

217262

250295

After 15 minutes 280 244 247 295

After 30 minutes 280 244 247 290After 60 minutes 277 244 247 290

After 120 minutes

272 244 247 290

Difference -18 -15 -15 -5

SHEAR REVERSIBILITY(AFTER 60 STROKES)TABLE 7

SHEAR REVERSIBILITY-(AFTER 60 STROKES)

200

210

220

230

240

250

260

270

280

290

300

0 15 30 60 120

diurea

tetraurea

hexaurea

octaurea

Fig.1

Shear reversibility

Diurea Tetra urea Hexa urea Octa urea

Penetration UnworkedWorked(x60)Worked(x 10K)

235255295

205260310

220265350

270305370

After 15 minutes 287 300 342 364After 30 minutes 287 300 342 364After 60 minutes 285 300 342 364After 120 minutes

285 300 342 364

Difference -10 -10 -8 -6

SHEAR REVERSIBILITY(AFTER 10 K STROKES)TABLE 8

Shear Reversibility (After 10 K strokes)

250

270

290

310

330

350

370

390

0 15 30 60 120

diurea

tetraurea

hexaurea

octaurea

Fig.2

Test D 217(modified)

DiureaG 020

Tetra ureaG 021

Hexa urea Octa urea

Penetration UnworkedPenetration after the test Difference

-

--

204

11391

225

123102

255

147108

HIGH TEMPERATURE HARDENING TEST-

TABLE 8

Test D 1264 Diurea Tetra urea Hexa urea Octa urea

% Loss in wt 0.30 0.42 0.90 1.20

WATER WASHOUT TEST-

TABLE 9

CONCLUSIONS-

- THIS WAS AN ATTEMPT TO STUDY THE PROPERTIES OF POLYUREA GREASES WITH DIFFERENT UREA GROUPS. THE RESULTS ARE BASED ON LIMITED STUDY CARRIED OUT IN LABORATORY. THE STUY IS BASED ON TYPICAL ISOCYNATES AND AMINES.

- TO EXPLAIN THE BEHAVIOR OF THESE GREASES, FURTHER DETAILED STUDY OF STRUCTURE AND PROPERTIES IS NEEDED USING THE MODERN ANALYTICAL TECHNIQUES SUCH AS SEM,TEM, MASS SPECTROMETRY ETC. TO ARRIVE AT SUITABLE CONCLUSIONS.

- IT IS OBSERVED THAT THE PROPERTIES OF POLYUREA GREASES VARY WITH NUMBER OF UREA GROUPS PRESENT.