King Fahd University of Petroleum and Minerals

King Abdulaziz City for Science and Technology

Sadhan Kumar De

Mamdouh Ahmad Al-Harthi

Omer Yahya Bakather

Reyad Awwad Khalaf Shawabkeh

Mamdouh Ahmed Al-Harthi

Masihullah Jabarulla Khan

Omer Bin Sohail

Farrukh Shehzad

Osamah Awadh Bin-Dahman

Jobin Jose

Abdul Kaleel Sulaiman Haniffa

Bijal Kottukkal Bahuleyan

Masiullah Jabarullah Khan

Methods of preparing high-density polyethylene (HDPE) nanocomposites by in situ polymerization with a metallocene catalyst and a methylaluminoxane co-catalyst in a solvent. The HDPE nanocomposites contain graphene nanofillers that promote the polymerization process, and are found to enhance the molecular weight, molecular weight distribution and flame retardency of the HDPE nanocomposites produced.

High-density polyethylene-graphene nanocomposites and methods thereof

Poly(acrylic acid) polymer blends comprising poly(acrylic acid) and glycerol, the glycerol content being 25-75% by weight based on the weight of the poly(acrylic acid). The polymer blends are miscible; they retain the ability to absorb large volumes of liquids and also exhibit rubber viscoelasticity. The incorporation of glycerol reduces the glass transition temperature of the blends dramatically. The process of preparing the poly(acrylic acid) polymer blends by solution casting is described. Methods of measuring the glass transition temperature and the tensile strength of the polymer blends are also provided.

Poly(acrylic acid)-glycerol blends

The method to produce ultra-high-molecular-weight polyethylene (UHMWPE) incorporates tungsten-doped titania (TiO/W) nanofiller during the ethylene polymerization process. The UHMWPE possesses improved mechanical and thermal properties. The process for producing the UHMWPE includes contacting ethylene under polymerization conditions with a polymerization catalyst (a vanadium (III) complex bearing bidentate salicylaldiminato ligands) in the presence of TiO/W nanofiller and a co-catalyst in a reactor. The reactor is charged with solvent (e.g., toluene) and heated to a temperature suitable for polymerization, e.g., about 30&#xb0; C. Following heating, the ethylene monomer is fed into the reactor and allowed to saturate for at least 10 minutes, and a methyl aluminum dichloride co-catalyst (MADC) is added to initiate polymerization of ethylene. Polymerization is quenched by adding methanol containing HCl incorporated with titania-tungsten nanofillers, which is then washed and dried to yield UHMWPE.

Method to produce ultra-high molecular weight polyethylene

The method of making polyolefin with a silicon nitride nano-filler uses silicon nitride (SiN) as a promoter for in situ polymerization with a zirconocene catalyst. The method includes adding the bis(cyclopentadienyl) zirconium dichloride catalyst and nanoparticles of silicon nitride to a reactor. The reactor is then charged with toluene and a methylaluminoxane co-catalyst, and is heated for a period of time sufficient to bring the reactor to a polymerization reaction temperature. Nitrogen gas is removed from the reactor following the heating, and then ethylene monomer is fed into the reactor, initiating polymerization. The polymerization is then quenched, and non-reacted monomer is vented. The polyolefin product is then removed from the reactor, washed and dried.

Method of making polyolefin with a silicon nitride nano-filler

The pressure sensitive adhesive is a copolymer of ethylene and propylene that has a maximum load between 6.4 N and 11.2 N in a lap joint shear strength test. The copolymer is prepared by mixing ethylene and propylene in the presence of a diimine nickel catalyst and polymethylaluminoxane (MAO) co-catalyst. The molar ratio of the ethylene to propylene feed is between 60:40 and 40:60. The polymerization is carried out at 30&#xb0; C. and 1.3 bar. The polypropylene molar percentage in the resulting copolymer is between 42% and 88%, and the weight average molecular weight is between 24,917 and 33, 314 Da. The copolymer is an amorphous polymer having a glass transition temperature (T) between &#x2212;63&#xb0; C. and &#x2212;66&#xb0; C.

Pressure sensitive adhesive

The ethylene/propylene copolymer nanocomposite is a copolymer prepared by inclusion of a filler of nanoparticles of titania doped with iron that permits control over, and variation of, the overall polymeric properties. Through the addition of the TiO/Fe nanofiller, the concentration of polypropylene in the copolymer is increased and the overall crystallinity is decreased. In order to make the copolymer, a TiO/Fe titania-iron nanofiller is first mixed with a polymerization catalyst (a vanadium (III) complex bearing bidentate salicylaldiminato ligands) in a reactor. The reactor is then charged with solvent (e.g., toluene) and heated to a temperature suitable for polymerization, e.g., about 30&#xb0; C. Following heating, a mixture of ethylene and propylene gases (in selected molar ratios) is fed into the reactor at a fixed pressure, and methyl aluminum dichloride co-catalyst (MADC) is added to initiate polymerization. Polymerization is quenched to yield the ethylene/propylene copolymer nanocomposite, which is then washed and dried.

Ethylene/propylene copolymer nanocomposite

The method of making high-density polyethylene with titania-iron nanofillers involves mixing a TiO/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&#xb0; 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 TiO/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.

Method of making high-density polyethylene with titania-iron nanofillers

The method for producing polyolefin nanocomposites uses an aluminum nitride (AlN) nano-filler as a promoter of olefin polymerization with a metallocene catalyst. The method of making the polyolefin nanocomposites begins by combining a metallocene catalyst, such as a zirconocene catalyst, with aluminum nitride in a reactor. The reactor is then charged with toluene and methylaluminoxane, methylaluminoxane acting as a co-catalyst. The reactor is then heated at a constant temperature, and ethylene is added to the reactor to initiate polymerization of a polyethylene nanocomposite. Polymerization is then quenched by the addition of acidic methanol to the reactor, and un-reacted monomer is vented from the reactor. The resultant polyethylene nanocomposite is then washed in methanol and dried. The aluminum nitride nano-filler promotes the conversion of the olefin monomer to the polyolefin.

Method of making polyolefin nanocomposites

The method of promoting olefin polymerization uses a nanoparticle filler to increase the activity of a metallocene catalyst for in situ polymerization of polyolefins. The filler may be nanoparticles of manganese, or nanoparticles of manganese-doped titanium dioxide. The method includes the steps of (a) mixing a metallocene catalyst, e.g., zirconocene dichloride, with nanoparticles of the filler in an organic solvent, e.g., toluene, in a reactor to form a reaction mixture; (b) immersing the reactor in a temperature bath for a period of time sufficient to bring the mixture to an optimal polymerization reaction temperature; (c) adding monomer to the mixture in the reactor; (d) adding methylaluminoxane (MAO) as a co-catalyst to the reaction mixture to initiate polymerization; and (e) quenching the polymerization, e.g., by adding methanol containing 5% hydrochloric acid by volume to the reactor.

Growing community of inventors

Dhahran, Saudi Arabia

Sadhan Kumar De