Diethylzinc

Stability: thermal, sunlight, metals

Administrative data

Endpoint:

thermal stability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Apparently well conducted study however a certificate of analysis was not included in the report and the experimental details are limited.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Qualifier:

no guideline required

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Diethylzinc

EC Number:

209-161-3

EC Name:

Diethylzinc

Cas Number:

557-20-0

Molecular formula:

C4H10Zn

IUPAC Name:

diethylzinc

Details on test material:

diethylzinc

Applicant's summary and conclusion

Conclusions:

The DEZ kinetic data are based on the results of 3 methods (DSC, TAM and ARC). From Arrhenius
the activation energy (Ea) = 124.8 kJ/mole and ln C= 37.48. The total heat of decomposition ΔHdec =
1244 kJ/kg.
For DEZ the DSC and TAM results agreed well. The ARC results tends to deviate from DSC and
TAM data. Therefore it is not recommended to extrapolate ARC kinetic data to lower temperatures.
The ARC data of Knoshaug and Akzo Nobel correspond well.

For a non insulated C-430 tank the self accelerating decomposition temperature (SADT) = 90 ºC.
The maximum storage temperature is 70 ºC.

With the overall kinetic parameters the adiabatic induction times (tad) were calculated.
The maximum safe handling time (tsaf,max) is derived from the adiabatic induction time:

t saf,max = 1/4 x tad

Executive summary:

Objective Thermal stability data of diethylzinc (DEZ), determined by means of Differential Scanning Calorimetry (DSC), Accelerating Rate Calorimetry (ARC) and Thermal Activator Monitor (TAM). The results provide kinetic decomposition data based on different methods which are measured in a wide temperature range.

Table 1. Maximum safe handling times DEZ at various temperatures:

Temperature (ºC)	Safe handling time (hours)
90	43.9
100	15.3
110	5.6
120	2.2
130	0.89
140	0.38
150	0.17
160	0.08

Maximum handling times are important for:

􀂄 destillation and other high temperature process operations

􀂄 dosing of DEZ at high temperatures to processing units and other high temperature applications

Possibilities for TAM measurements with other metal alkyls are limited because the maximum operation temperature of the TAM equipment is 90 °C. For most metal alkyls this temperature is too low to detect any heat production.