Method of quantitative determination of nonisothermal thermooxidative degration effects of a polyolefin material comprising a residual catalyst

Patent metadata

Field	Value
Publication number	US-9836584-B2
Application number	US-201314144216-A
Country	US
Kind code	B2
Filing date	Dec 30, 2013
Priority date	Dec 30, 2013
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A method for quantitative determination of nonisothermal thermooxidative degradation effects of a polyolefin material containing a residual catalyst. The method includes determining a first thermooxidative degradation by obtaining a thermogravimetric analysis spectrum of polyolefin, and then modifying the first thermooxidative degradation based on a structure of the residual catalyst to obtain final thermooxidative degradation properties of the polyolefin.

First claim

The invention claimed is:

1. A method of quantitatively determining one or more nonisothermal thermooxidative degradation effects of a polyolefin material comprising a residual catalyst, the method comprising:
obtaining a thermogravimetric analysis spectrum of the polyolefin; and
determining a nonisothermal thermooxidative degradation property of the polyolefin with a rigorous constitutive kinetic model based on a structure of the residual catalyst in the thermogravimetric analysis spectrum;
wherein the rigorous constitutive kinetic model is

r
=

d
⁢

⁢

W
fraction

d
⁢

⁢
t

=

-
Z

⁢

⁢

exp
⁡

[

-

E
a

R
⁢

⁢

(

1
T

-

1

T
0

)

]

⁢

W
fraction
n

,

wherein
r is an overall rate of degradation,
R is universal gas constant,
Ea is apparent activation energy,
T is absolute temperature in K,
T 0 is a centering temperature that resides around a mean temperature range of the reaction,
Z is a frequency factor,
n is overall order of degradation, and
W fraction is a post-degradation weight fraction of a sample of the polymer.

2. The method of claim 1 , wherein the polyolefin material is an ethylene homopolymer synthesized with a Ziegler-Natta catalyst.

3. The method of claim 2 , wherein the polyolefin material is an ethylene homopolymer synthesized with a metallocene catalyst.

4. The method of claim 2 , wherein the Ziegler-Natta catalyst comprises silica, dibutylmagnesium, tetramethoxysilane, and titanium tetrachloride in reacted form.

5. The method of claim 3 , wherein the metallocene catalyst comprises silica, ( n BuCp) 2 ZrCl 2 , and methylaluminoxane in reacted form.

6. The method of claim 1 , wherein obtaining a thermogravimetric analysis spectrum of the polyolefin material comprises heating the polyolefin material, from room temperature to 600° C. at a rate of 20° C./min.

7. The method of claim 1 , wherein T 0 is 725° K.

8. The method of claim 1 wherein Ea is 122-162 kJ/mol.

9. The method of claim 1 , wherein Z is 1.2×10 −3 to 2.8×10 −3 sec −1 .

10. The method of claim 1 , wherein n is 1.

Assignees

• Univ King Fahd Pet & Minerals
• King Abdulaziz City Sci & Tech
• King Abdulaziz City Of Science And Tech

Inventors

• Atiqullah Muhammad
• Hossain Mohammad Mozahar

Classifications

• G16C20/10 Primary

  Analysis or design of chemical reactions, syntheses or processes · CPC title

• G06F19/702 Primary

  Physics · mapped topic