Kim L. Walton

Bio: Kim L. Walton is an academic researcher from Dow Chemical Company. The author has contributed to research in topics: Polyolefin & Thermoplastic. The author has an hindex of 21, co-authored 70 publications receiving 1555 citations. Previous affiliations of Kim L. Walton include University of Minnesota.

Thermoplastic vulcanizate comprising interpolymers of ethylene/α-olefins

Abstract: Thermoplastic vulcanizates comprise at least an ethylene/α-olefin interpolymer and at least one thermoplastic polymer, such as polyolefin. The ethylene/α-olefin interpolymer is a block copolymer having at least a hard block and at least a soft block. The soft block comprises a higher amount of comonomers than the hard block. The block interpolymer has a number of unique characteristics disclosed here. The block interpolymer is either used as a compatibilizer between a vulcanizable elastomer and a thermoplastic polymer or as a vulcanizable elastomer when it is in the EPDM form. The thermoplastic vulcanizates can be profiled extruded to make profiles and gaskets.

Polymer blends from interpolymer of ethylene/alpha olefin with improved compatibility

Abstract: Disclosed herein are polymer blends comprising at least one ethylene/α-olefin interpolymer and two different polyolefins which can be homopolymers. The ethylene/α-olefin interpolymers are block copolymers comprising at least a hard block and at least a soft block. In some embodiments, the ethylene/α-olefin interpolymer can function as a compatibilizer between the two polyolefins which may not be otherwise compatible. Methods of making the polymer blends and molded articles made from the polymer blends are also described.

Impact Modification of Thermoplastics with Ethylene/Alpha-Olefin Interpolymers

Abstract: Compositions having good impact performance can be made from a thermoplastic (e.g., a polyolefin such as polypropylene or HDPE) and an ethylene multi-block copolymer. The compositions are easily molded and often have particular utility in making, for example, automotive facia, parts and other household articles.

Investigation of processing-structure-properties relationships in polyethylene blown films

Abstract: Molecular orientation imparted during film fabrication is known to have a major effect on mechanical and thermal properties of both glassy and semicrystalline polymers. A three-variable Box-Behnken designed experiment was used to study the effects of die gap, die land length, and blowup ratio (BUR) on key linear low density polyethylene (LLDPE) blown film properties at constant final film thickness. In addition, differences in molecular orientation in the films were studied using optical birefringence and shrinkage methods. Measured key film properties were correlated to processing conditions and to measured molecular orientation. Die land length had no significant effect on film structure and properties. All LLDPE films exhibited about 70 to 80% shrinkage in the machine direction (MD) but expanded in the cross direction (CD). Most films exhibited negative in-plane birefringence. MD Elmendorf tear was found to be inversely related to drawdown ratio and MD shrinkage, suggesting that MD tear is dependent primarily on amorphous chain extension and hence, amorphous segments orientation for LLDPE blown films. Dart impact strength of the films was shown to be related to MD shrinkage and to the induced surface roughness due to varying die gap. In a separate study, blown films of three high pressure LDPEs were fabricated under nearly identical conditions. No correlation was found between birefringence and shrinkage data on the LDPE blown films.

Low molecular weight ethylene/alpha-olefin interpolymer as base lubricant oils

Abstract: A lubricant composition comprises an ethylene/α-olefin interpolymer having a number average molecular weight of less than 10,000 g/mol as a base oil and at least one oil additive. The ethylene/α-olefin interpolymer has at least one molecular fraction which elutes between 40° C. and 130° C. when fractionated using TREF, characterized in that the fraction has a molar comonomer content of at least 5 percent higher than that of a comparable random ethylene interpolymer fraction eluting between the same temperatures, wherein said comparable random ethylene interpolymer has the same comonomer(s) and has a melt index, density, and molar comonomer content (based on the whole polymer) within 10 percent of that of the ethylene/α-olefin interpolymer.

Catalyst composition comprising shuttling agent for ethylene multi-block copolymer formation

Abstract: A composition for use in forming a multi-block copolymer, said copolymer containing therein two or more segments or blocks differing in chemical or physical properties, a polymerization process using the same, and the resulting polymers, wherein the composition comprises the admixture or reaction product resulting from combining: (A) a first metal complex olefin polymerization catalyst, (B) a second metal complex olefin polymerization catalyst capable of preparing polymers differing in chemical or physical properties from the polymer prepared by catalyst (A) under equivalent polymerization conditions, and (C) a chain shuttling agent.

Ethylene/alpha-olefins block interpolymers

Abstract: Embodiments of the invention provide a class of ethylene/α-olefin block interpolymers. The ethylene/α-olefin interpolymers are characterized by an average block index, ABI, which is greater than zero and up to about 1.0 and a molecular weight distribution, M w /M n , greater than about 1.3. Preferably, the block index is from about 0.2 to about 1. In addition or alternatively, the block ethylene/α-olefin interpolymer is characterized by having at least one fraction obtained by Temperature Rising Elution Fractionation (“TREF”), wherein the fraction has a block index greater than about 0.3 and up to about 1.0 and the ethylene/α-olefin interpolymer has a molecular weight distribution, M w /M n , greater than about 1.3.

Compositions of ethylene/alpha-olefin multi-block interpolymer for elastic films and laminates

Abstract: This invention relates to polyolefin compositions. In particular, the invention pertains to elastic polymer compositions that can be more easily processed on cast film lines, extrusion lamination or coating lines. The compositions of the present invention preferably comprise an elastomeric polyolefin resin and a high pressure low density type resin.

Elastic substantially linear ethylene polymers

Abstract: Elastic ethylene polymers are disclosed which have processability similar to highly branched low density polyethylene (LDPE), but the strength and toughness of linear low density polyethylene (LLDPE). The polymers have processing indices (PI's) less than or equal to 70 percent of those of a comparative linear ethylene polymer and a critical shear rate at onset of surface melt fracture of at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a traditional linear ethylene polymer at about the same I 2 and M w /M n . The novel polymers can also have from about 0.01 to about 3 long chain branches/1000 total carbons and have higher low/zero shear viscosity and lower high shear viscosity than comparative linear ethylene polymers. The novel polymers can also be characterized as having a melt flow ratio, I 10 /I 2 , ≧5.63, a molecular weight distribution, M w /M n , defined by the equation: M w /M n ≦(I 10 /I 2 )-4.63, a critical shear stress at onset of gross melt fracture greater than about 4×10 6 dyne/cm 2 , and a single DSC melt peak between -30 C. and 150 C.