# US 8,541,520 B1 · Method of making high-density polyethylene with titania-iron nanofillers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,541,520 B1 - Document ID: US8541520B1 - Status: Granted - Kind: B1 - Application number: 13/746,258 - Filed: 2013-01-21 - Granted: 2013-09-24 - Earliest claimed: 2013-01-21 - Assignees: King Fahd University of Petroleum and Minerals - Applicants: King Fahd University of Petroleum and Minerals - Inventors: Mamdouh Ahmad Al-Harthi; Omer Yahya Bakather; Sadhan Kumar De; Reyad Awwad Khalaf Shawabkeh - Web page: https://patentgrep.com/patent/US8541520B1 ## CPC - C08F 110/02: Ethene - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS ## Abstract The method of making high-density polyethylene with titania-iron nanofillers involves mixing a TiO2/Fe titania-iron nanofiller with a vanadium (III) complex bearing salicylaldiminato ligands polymerization catalyst in a reactor. The reactor is then charged with toluene and heated to a temperature of about 30° C. Following heating, ethylene is fed into the reactor at a fixed pressure, and a methyl aluminum dichloride cocatalyst is added to initiate in situ polymerization. Polymerization is quenched to yield high-density polyethylene with titania-iron nanofillers, which is then washed and dried. Through the addition of a TiO2/Fe nanofiller, the molecular weight, the crystallinity and the melting temperature of high-density polyethylene are all increased, while the polydispersity index (PDI) is decreased. ## Claims ### Claim 1 A method of making high-density polyethylene with increased molecular weight with titania-iron nanofiller, comprising the steps of: mixing nanoparticles of an iron-doped titanium dioxide filler with a polymerization catalyst in an organic solvent in a reactor to form a reaction mixture; heating the reactor for a period of time sufficient to bring the reaction mixture to a polymerization reaction temperature; feeding ethylene monomer into the reactor; adding methyl aluminum dichloride as a co-catalyst to the reactor to initiate in situ polymerization; and quenching the polymerization. ### Claim 2 (depends on 1) The method of making high-density polyethylene with increased molecular weight as recited in claim 1, wherein the polymerization catalyst is a vanadium (III) complex with salicylaldiminato ligands having the formula: ### Claim 3 (depends on 1) The method of making high-density polyethylene with increased molecular weight as recited in claim 1, wherein the polymerization reaction temperature is about 30° C. ### Claim 4 (depends on 1) The method of making high-density polyethylene with increased molecular weight as recited in claim 1, wherein the step of quenching the polymerization comprises adding methanol containing 5% hydrochloric acid by volume to the reactor. ### Claim 5 (depends on 1) The method of making high-density polyethylene with increased molecular weight as recited in claim 1, wherein the nanoparticles of iron-doped titanium dioxide have a particle size less than 10 nm. ### Claim 6 (depends on 1) The method of making high-density polyethylene with increased molecular weight as recited in claim 1, further comprising the step of removing nitrogen from the reactor prior to the step of feeding ethylene monomer into the reactor. ### Claim 7 (depends on 1) The method of making high-density polyethylene with increased molecular weight as recited in claim 1, wherein said step of feeding ethylene monomer into the reactor comprises feeding ethylene monomer into the reactor at a pressure of about 1.3 bar. ### Claim 8 (depends on 1) The method of making high-density polyethylene with increased molecular weight as recited in claim 1, wherein said organic solvent comprises toluene. ### Claim 9 (depends on 1) The method of making high-density polyethylene with increased molecular weight as recited in claim 1, wherein said step of feeding ethylene monomer into the reactor comprises saturating the solvent with ethylene monomer. ### Claim 10 (depends on 1) High-density polyethylene with increased molecular weight made according to the method of claim 1. ### Claim 11 (depends on 1) The method of making high-density polyethylene with increased molecular weight as recited in claim 1, further comprising the steps of: hydrolyzing titanium (IV) alkoxide precursor in ethanol solvent in the presence of about 1 mL of water at room temperature to form a solution of hydrolyzed titania particles; adding an ethanolic solution of Fe(NO3)3.9H2O precursor to the solution of hydrolyzed titania particles to form a mixture; sonicating the mixture to form a precipitate; washing the precipitate in ethanol; drying the precipitate; and heating the precipitate to convert amorphous titania into crystalline anatase titania; grinding the precipitate to form the nanoparticles of the iron-doped titanium dioxide filler. ### Claim 12 (depends on 1) The method of making high-density polyethylene with increased molecular weight as recited in claim 1, wherein iron forms about 1% by weight of said nanoparticle filler. ### Claim 13 A method of making high-density polyethylene with increased molecular weight with titania-iron nanofiller, comprising the steps of: mixing nanoparticles of an iron-doped titanium dioxide filler with a polymerization catalyst in an organic solvent in a reactor to form a reaction mixture, the polymerization catalyst being a vanadium (III) complex with salicylaldiminato ligands having the formula: heating the reactor for a period of time sufficient to bring the reaction mixture to a polymerization reaction temperature; feeding ethylene monomer into the reactor; adding methyl aluminum dichloride as a co-catalyst to the reactor to initiate in situ polymerization; and quenching the polymerization. ### Claim 14 (depends on 13) The method of making high-density polyethylene with increased molecular weight as recited in claim 13, wherein iron forms about 1% by weight of said nanoparticle filler. ### Claim 15 (depends on 13) High-density polyethylene with increased molecular weight made according to the method of claim 13.