High-density polyethylene preparation methods

Patent metadata

Field	Value
Publication number	US-2017009049-A1
Application number	US-201514796885-A
Country	US
Kind code	A1
Filing date	Jul 10, 2015
Priority date	Jul 10, 2015
Publication date	Jan 12, 2017
Grant date	—

Abstract

Methods of preparing high-density polyethylene (HDPE) nanocomposites by in situ polymerization with a zirconocene catalyst, a methylaluminoxane cocatalyst, a calcium zirconate nanofiller in a solvent. The calcium zirconate nanofiller, which is dispersed across the polyethylene matrix, is found to enhance catalyst activity, and other properties of the HDPE nanocomposites produced, including but not limited to flame retardency, crystallinity and surface morphology.

First claim

1 . A method for producing a high-density polyethylene nanocomposite, comprising:
polymerizing, in a reactor, ethylene in a polymerization mixture comprising a zirconocene catalyst, a methylaluminoxane cocatalyst and a calcium zirconate nanofiller to form the high-density nanocomposite; wherein the calcium zirconate nanofiller is dispersed in a polyethylene matrix.

2 . The method of claim 1 , wherein the calcium zirconate nanofiller is present, during the polymerizing, in an amount of 0.02-3.0 wt. % per total weight of the high-density polyethylene nanocomposite produced.

3 . The method of claim 1 , wherein the polymerizing is carried out in a solvent.

4 . The method of claim 3 , wherein the polymerizing is carried out on toluene.

5 . The method of claim 4 , wherein the zirconocene catalyst has a concentration of 10-30 μmol in the toluene.

6 . The method of claim 4 , wherein the methylaluminoxane cocatalyst is present, during the polymerizing, at a methylaluminoxane/toluene volume ratio of 1:10-20.

7 . The method of claim 1 , wherein the polymerizing is carried at 1.0-1.5 bar.

8 . The method of claim 1 , wherein the polymerizing is carried at 25-35° C.

9 . The method of claim 1 , wherein the reactor is a Schlenk flask comprising a glove box.

10 . The method of claim 4 , further comprising:
dissolving the zirconocene catalyst and the calcium zirconate nanofiller in the toluene in the presence of an inert gas in the reactor; removing the inert gas from the reactor and injecting the ethylene into the reactor; and adding the methylaluminoxane cocatalyst into the polymerization mixture.

11 . The method of claim 1 , wherein the calcium zirconate nanofiller has an average particle size of 30-75 nm.

12 . The method of claim 1 , wherein the calcium zirconate nanofiller increases activity of the zirconocene catalyst by 5-45%.

13 . The method of claim 1 , wherein the calcium zirconate nanofiller converts the polyethylene matrix from a fibrillar morphology to a smooth morphology.

14 . The method of claim 1 , producing a high-density polyethylene nanocomposite having 60-80% crystallinity.

15 . The method of claim 1 , producing a high-density polyethylene nanocomposite having a molecular weight of 30-80 kDa.

16 . The method of claim 1 , producing a high-density polyethylene nanocomposite having a heat release rate of 1200-1300 W/g.

17 . The method of claim 1 , producing a high-density polyethylene nanocomposite having a decomposition temperature of 500-525° C.

18 . The method of claim 1 , producing a high-density polyethylene nanocomposite that is non-flammable.

19 . The method of claim 1 , producing a high-density polyethylene nanocomposite having a polydispersity index of 2.0-3.0.

20 . A high-density polyethylene nanocomposite produced by the method of claim 1 .

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Al-Harthi Mamdouh Ahmed

Classifications

• C08F2/44 Primary

  Polymerisation in the presence of compounding ingredients, e.g. plasticisers, dyestuffs, fillers · CPC title

• C08K3/22 Primary

  of metals · CPC title

• B01J20/291

  Gel sorbents · CPC title

• C08L23/06 Primary

  Polyethylene · CPC title

• C08K3/24

  Acids; Salts thereof {(C08K3/16 takes precedence)} · CPC title