Rudolf Riesen April 2009 - vansolix.comvansolix.com/capacitacionmt/Capacitacion MT Analitico marzo...

Applications MP Systems

Rudolf RiesenApril 2009

Author: R. RiesenDate: April 09; V1.1Approved: M. Wagner

Internal usage only

Agenda

� Melting point determination; statistics, precision

� Identification by mixed melting point

� Melting and decomposition

� Melting point of inorganic substances

� Liquid crystals

� Phase transition with color changes

� Identification of rubber chemicals (ASTM D1519)

� Melting of polymers

� Overview of standards

� Summary

1

Melting events

JIS K 0064 – 1992

Test methods for melting point and melting range of chemical products

2

Melting events

Measurement of the light transmission� A: Start of melting

� B: Melting point (intensity 40%)

� C: End of melting

� Pharmacopeia: furnace temperature

� Thermodynamic: corrections by thermal lag:

fA = 0.2 KfB = 1.5 KfC = 2.0 K

ββ fTT −= )(phth

3

Analysis of the melting of benzoic acid (I)

Data: 15 sets of 6 benzoic acid test specimens measured in the MP. Heating rate 1 K/min; thermodynamic melting temperature

1 2 3 4 5 6122.2

122.3

122.4

122.5

122.6

122.7

122.8

122.9

123.015 measurements

Mel

ting

tem

pera

ture

in °C

Position4

Dependency of the melting point on the filled heigh t(25 mm in the video = 4 mm in the capillary)

Analysis of the melting of benzoic acid (II)

122.3 122.4 122.5 122.6 122.7 122.8 122.920

22

24

26

28

30 ρ = 0.49

Fill

hei

ght i

n m

m

Melting temperature in °C5

Distribution of the melting point : Gaussian (χ2 = 1.5; χ2krit = 7.8)

Analysis of the melting of benzoic acid (III)

122.2 122.4 122.6 122.8 123.00

5

10

15

20

25

Fre

quen

cy

Melting Temperature in °C

Measured

Gaussian µ = 122.56 °C σ = 0.133 °C

6

Analysis of the melting of benzoic acid (IV)

Comparison MP – FP results (Certified material: 122.3 ±0.2 °C)

F-test for the standard deviations of the MP and the FP results: the 2 standard deviations are compliant to each other; i.e. the precision of the 2 instruments regarding the melting point of benzoic acid is the same.

Remark: the results show, that the 95% confidence interval is well below the specified precision of the reference material. This raises questions:

- are our instruments so outstanding?

- is the reference material so poorly specified?

- what is precision?

7

MP FP n 85 21 Mean 122.56 °C 122.51 Standard deviation 0.13 °C 0.10 °C

Confidence interval (95 %) (based on 6 capillaries)

0.09 °C

0.07 °C

Remarks to the notion of “Precision” (I)

Precision can be defined on different levels

System Precision

Repeatabilitydifferent sample preparation

Intermediate Precisiondifferent operator, instrument, time

Reproducibilitydifferent labs, time (long term)

8

Remarks to the notion of “Precision” (II)

� System precision: the same test specimen is measured under identical conditions

� Repeatability: the same operator prepares and measures several test specimens under otherwise identical conditions

� Intermediate precision: several operators prepare and measure several test specimens on different instruments with the same methods

� Reproducibility: the same sample is measured under intermediate precision conditions in several laboratories.

� The precision indicated on reference materials should correspond to a reproducibility precision

� The precision indicated here for benzoic acid measurements corresponds to a repeatability precision

9

Internal usage only

Agenda

� Melting point determination, statistics, precision


� Melting of critical substances, decomposition


� Liquid crystals





� Summary

10

Identification by mixed melting point

� Two samples of urea have to be compared.

� The measurements shall show if both samples are of the same chemical.

� Procedure:Determination of the melting points of the individual substances and the melting point of the 1:1 mixture.

� Equipment: MP90 is used.

� Sampling:6 capillaries were filled for each measurement (totally 36).

� Method:Melting range according to pharmacopeia (1 K/min, furnace temperature).

11


� Lit. Value: 132 - 135 °C (Ph.EUP. 2.2.14)

� Decomposing

12


Results

Same chemicals; Urea 2 is a little less pure

13

131

132

133

134

135

136

Urea 2Urea 1

Tem

pera

ture

in °C

Mixture

Melting and decomposition

� Sample: Sugar

� Method: - Operation mode: Melting point- Criterion: Threshold 10%- Start temp.: 180 °C- Rate: 1 °C/min- End temp.: 190 °C- Temp. Values: Pharmacopeia

� Results: - Mean value: 187.3 °C- Std. dev.: 0.1 °C

Decomposition

14

Critical results:

� Melting point is scattered

� Transmission curves are not regular

� Samples get brownish

� Check the video for bubbles

New definition: blow point

Melting and decomposition

15

Internal usage only

Agenda





� Liquid crystals





� Summary

10

Inorganic substances

� Sample: Potassium nitrate (KNO3)

� Method: - Operation mode: Melting point- Criterion: Threshold 40%- Start temp.: 328 °C- Rate: 1 °C/min- End temp.: 339 °C- Temp. Values: Thermodynamic

� Results:- Mean value: 334.67 °C- Std. dev.: 0.18 °C

Melting Point

17

Liquid crystal

Azoxydianisol: nematic – isotropic transition

Start of transition: 133.12 °C ±1.42 °CEnd of transition: 134.27 °C ±0.02 °C

Melting of crystals LC Transition

18

Liquid crystal

Transmission light

19

Liquid crystal

20

Thermo chromic substance

Thermo chromism

Transition with color change

� Sample: HgI2� Method:

- Operation mode: Set manually

- Start temp.: 120 °C

- Rate: 5 °C/min- End temp.: 155 °C

- Temp. Values: Pharmacopeia

� Results:- Point 1: 142.25 °C- Point 2: 155.00 °C

21

Thermo chromic substance

Phase transition with color change:

137 °C 145 °C

148 °C 155 °C22

Color changes by loss of water

CuSO4·5H2O CuSO4·3H2O CuSO4·1H2O CuSO4

60 °C 110 °C

150 °C 280 °C23

Internal usage only

Agenda





� Liquid crystals





� Summary

10

ASTM D1519, rubber chemicals

ASTM D1519 - 95(2004)e1 Standard Test Method for Rub ber Chemicals - Melting Range

1. Scope1.1 These test methods cover the determination of the melting range of commercial rubber processing chemicals either by use ofcapillary melting point tubes or by differential scanning calorimetry (DSC).

6. Apparatus6.1 Melting Apparatus—Any electric melting apparatus that satisfies the requirements of Test Method E 324 may be used or any suitable manually heated oil bath such as Hershberg tube.

E324 (withdrawn) :1. Scope1.1 This test method covers the determination, by a capillary tube method, of the initial melting point and the final melting point, which define the melting range, of samples of organic chemicals whose melting points without decomposition fall between 30 and 250°C.

25


� Tested substances (listed in ASTM D1519-82)- TETD (Tetraethylthiuramidsulfid): 69 – 70 °C

- PBNA (Phenyl-beta-naphtylamin): 104 -107 °C- MBT (Marcaptobenzothiazol): 175 – 180 °C

� Industrial applications:- TETD: accelerator for vulcanization reactions

- PBNA: antioxidant for rubbers- MBT: accelerator and antioxidant in rubbers

� Experimental:- Melting range (pharmacopeia)

- Tstart = Texpected – 10 K

- Rate: 1 K/min- Double determination

26


Melting ILT FP81HT MP90TEDT Tstart x in °C 69.00 70.00 70.60

s in °C 0.03 0.11 0.03Tend x in °C 70.80 70.50 71.60

s in °C 0.21 0.07 0.18PBNA Tstart x in °C 103.80 107.50 107.30

s in °C 0.28 0.78 0.07Tend x in °C 107.40 §1 108.40

s in °C 0.23 0.20MBT Tstart x in °C 174.80 178.30 177.20

s in °C 0.49 0.39 0.13Tend x in °C 179.60 §1 181.10

s in °C 0.43 0.24

x mean of 12 specimens standard deviation

§1 transmission below 20%

ILT: inter-laboratory round robin test in 1982

27

Polymers

Polymers

� Sample: Lupolen 1800H & 6031HLDPE, HDPE

� Method: - Operation mode: Melting point

- Start temp.: 95/125 °C

- Rate: 5 °C/min- End temp.: 125/145 °C

- Temp. Values: Thermodynamic

� Results:- LDPE: 103.49 °C- HDPE: 132.40 °C ISO 3146 (Plastics – Determination of melting

behavior of semi-crystalline polymers)

28

Overview of standards

Ph.Eur. 2.2.60 (Melting point – Instrumental method)

29

Overview of standards

Complying (metal block, automatic detection)� Mentioned in brochure

- Ph.Eur. 2.2.60 (Melting point – Instrumental method)- USP <741> (Melting range or temperature)- JIS K 0064 (Melting point and melting range of chemical products)- ASTM D1519 (Rubber Chemicals – Determination of Melting Range)

� Additional- ISO 3146 (Plastics – Determination of melting behavior of semi-crystalline

polymers)

Close standards (for example oil bath with thermome ter)

� Japanese Pharmacopeia

� AOCS Cc 1-25 (Melting Point, Capillary Tube Method)

Manual standards should be replaced by MP90 procedu re

30

Summary

Application MP50 MP70 MP90 Melting point • • • Melting range • • • Purity determination • • • Decomposition temperature � • • Solvent loss � • • Sublimation � • • Change in the crystal structure � • • Sintering point � • • Color change • • Thermochromism • • High throughput analysis •

• Suitable � partly suitable31

Acknowledgment

The measurements have been performed by my colleagues:� Claudia Frisch� Angela Hammer� Ni Jing� Myrta Pfister � Nicolas Fedelich� Kai Hassdenteufel� Thomas Oberholzer � Jürgen Schawe � Markus Schubnell� Matthias Wagner

32

Discussion

Questions

Answers

33

Excellence Melting Point Systems

April 2009

Rudolf Riesen April 2009 - vansolix.comvansolix.com/capacitacionmt/Capacitacion MT Analitico marzo...

Documents

Transcript of Rudolf Riesen April 2009 - vansolix.comvansolix.com/capacitacionmt/Capacitacion MT Analitico marzo...