Physical Properties of Glycerine - aciscience.org

1 Physical Properties of Glycerine HE extremely wide range of uses T for Glycerine is due in large mea- sure not to a single property, but to its unique combination of Properties . Nature made glycerol the most widely distributed of the polyhydric alcohols, as combined in fats and other lipids essential to life pro- cesses. Derivatives dependent on its chemical structure have now been extended to virtually every field of research and technology, from ex- plosives to emulsifiers. Glvcerine (sometimes glycerin) is the term most often applied to the commercial product, which usually contains a small percentage of wa- ter.

2 Glycerol (chemically, also 1,2,3- propanetriol) refers to the chemical compound and content in a formula- tion. specifically to the trihydric alcohol C, H, (OH) ::. But over and above its chemical combinations, pure Glycerine offers the formulator a liquid with a for- tuitous balance of Physical proper- ties, brand, viscous, stable, hygro- scopic and widely compatible. In the area of products for personal use it is clear, odorless and recognized as safe. It prevents freezing and pro- motes long shelf life. This booklet highlights another distinct advantage of Glycerine for the developer of new products.

3 All its Properties , even those of seem- ingly esoteric interest, have been spread on the record by over a cen- tury of scientific study. If there is a need to know its dielectric constant, and Its Solutions its coefficient of expansion or the rate of sound transmission through Glycerine , a handbook reference may save hours of critical measurement. Our aim in this compilation is to ' present the more important of the available data on Glycerine and its aqueous solutions for ready refer- ence. Other sections dealing with chemical and biological Properties are also being made available.

4 The material here condenses and brings up to date information originally compiled by C. S. Miner and N. N. Dalton in GLYCEROL (American Chemical Society Monograph 1 17) 1953; published and copyrighted by Reinhold Publishing Corp. to whom we are indebted for permission to use many of the tables and charts contained herein. Table 1. Specific Gravity and Per Cent Glycerol - by Weight Clyc- erol (%) 100 99 98 07 96 95 94 93 92 91 90 80 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 61 63 62 61 60 59 58 57 56 55 54 53 52 51 "2%- (') 2 :! 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 lS/lS*C :::gE ::;% ~) - IS/IS'C )5 1.

5 I9365 1 .I6875 ISIIS'C 2S/2S0C Apparent *C 1 .I6855 1 .I3245 Specihc Cnvity 20/20 C 1 .lo705 1'15605 Appucnt lS3/1 SJoC :::gi! ::;g$ Gnviw )0/20'C 1-18330 1'15585 ZSBT.

6 1 .I6560 1 .I6285 1'15460 lS/lS*C Trua SWc lSJ/lSJ*C 1'15725 Spddc Gravity 10/20*C :::%: :::% ' ZS/U*C Tnre Spddc 'C -------- ::izg :::::: 1 .OM55 1 .04345 Gnvit). 20/20*C Table 2.

7 Specific Gravity of Aqueous Glycerine Solutions with Glycerol Concentrations between 95-100% S. G. 0 1 2 3 4 5 6 7 8 9 Specific Gravity.

8 Glycerol (%I I00 99 98 97 06 85 94 93 92 91 90 89 88 87 9d 55 94 33 82 31 30 79 78 77 76 75 74 73 72 71 70 69 68 67 64 65 64 63 62 61 60 59 58 57 Jb. 55 54 53 52 11 Measurement of specific gravity is the principal means of determining the glycerol content of distilled Glycerine . Specific gravity is best de- termined with a pycnometer('). A Westphal balance or a hydrometer is less satisfactory because of the viscosity of concentrated Glycerine . Many determinations of the spe- cific gravity of glycerol and its water solutions have been publishedc2). Some of these are of questionable accuracy because the glycerol then available contained impurities such as polyglycerol or trimethylene gly- col.

9 In 1927, Bosart and Snoddyc3) published their determination of the specific gravity of glycerol solutions, as measured under carefully con- trolled conditions at 151 15, , 20120 and 25/25 & " C. These figures for apparent specific gravity, and the calculated figures for true specific gravities (in vacuum) are given in Table 1. They have been widely used in the industry. Another set of specific gravity determinations which has been em- ployed in the industry are those de- termined by Timmermans(4) which show slight differences in the fourth and fifth decimal places.

10 For 100% concentration at 15/4" C., the fol- lowing true specific gravities were found: Bosart & Snoddy .. Timmermans .. Table 2 has been calculated from Timmermans results, corrected to apparent specific gravity at '601- 60" F. = It shows concen- trations corresponding to tabulated values of specific gravity at 60" F. Table 3. Density & Density at Percent Glycerol (%) 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 of Glycerol 1,21650 1,20305 1,20545 19 18 17 16 I5 14 13 12 11 I0 9 8 7 6 5 4 3 2 1 0 1.