this presentation slide is intended in particular for internal discussion only

Introduction to High Molecular Weight Polyethylene

INTRODUCTION TO HIGH MOLECULAR WEIGHT MEDIUM DENSITY POLYETHYLENE

Bimodal Polyethylene

MWD Definition

• MWD describes the relationship between the number of moles of each polymer species (Mn) and the molar mass (Mw) of that species

• The most common technique for measuring molecular weight used in modern times is a variant of high pressure liquid chromatography (HPLC) known by the interchangeable terms of size exclusion chromatography

MWD in 3D

How to Make It Happen

Multi Stage ReactorUsing two different reactors (and catalyst) to form the bimodal polyethylene

Multiple Catalyst SystemUsing two different single site catalyst components in one reactor to form bimodal polyethylene

Current Well Known Catalyst Group 15 Containing Metal

Compound Bulky Ligand Metallocene-Type

Compound Conventional-Type Catalyst Systems

Combinable with Formula I and II Conventional-type Transition Metal

Catalysts

Main Element in One Catalyst System

Support CatalystElectron DonorCo-CatalystMetal Transition Impregnation MethodCatalyst Activation

Reactor Behavior

Gas CompositionReaction TemperatureImportance of Co-Monomer

Hydrogen as MWD Modifier

Introduction to Antioxidant

The typical technical manifestation of oxidation as referred as aging phenomena

The effect of oxidation are collectively termed degradation caused by : Such of degradation impurities carry over such as

peroxide alcohol, ketone, aldehyde acid, paracid etc;

rate increase caused by elevated temperature, wrong irradiation and catalysts such as metal & metal ion;

subsequent processing and expose of finish product over many years

Principle of Oxidative Degradation Crystallization or relaxation process can

cause aging furthermore can increase the sensitivity to degradation

Chain scission process through hydrolysis undergo degradation especially in polyester polyamides and polyurethane

Fillers, pigments, reinforcing material and other additives can cause overall degradation

Inhibited autoxidation Step by step

H* donor O2

RHROOH

*OH

RO*

R* ROO*

Hydroperoxide Decomposer

Radical Scavenger

Complexing Agent

RHO2

Additive System for HMWMDPE Irgafos 168

Phospites antioxidant, it works by decomposing peroxides and provides protection to adhesive, plastics and coatings during high temperature processing but not during end-use at elevated temperatures

Irganox 1010Hindered phenol to achieve synergetic performance, acting as H-donors are known to act as antioxidant in vivo, may cause discoloration of the polymer

Basic antioxidant mechanism H donor - Aromatic amine

Secondary aromatic amine and sterically hindered phenol are excellent H donor

Discolor and stain the end product and application in plastic

Not approved for indirect food contact applicationthe abstraction of hydrogen lead to form of aminyl and mesomeric C centered radical, both species may involved in C radical scavenging

Basic antioxidant mechanismHydroxyperoxide decomposer

Phosphites & Phosphonites Phosphite are oxidized in stoichiometric way to

the phosphates The remaining alkyl radical can undergo

disproportionation or fragmentation under oxygen deficient condition

The use of suitable alkyl radical scavenger with HD contribute to the overall melt stability during processing

The sensitivity to hydrolysis leading to acidic species can cause problem such as corrosion of metal parts in processing equipment

Main Properties for HMWMDPEHigher Stiffness (higher density)Higher Chemical Resistance, ESCR

Higher Impact (RCP)Low Die Swell (Barus effect)Low DegradationNo Bad Odor (TOT)

Exclusive Properties for PE Pipe

Bench Top Impact Test for Rapid Crack Propagation (RCP) ResistanceRapid crack propagation was measured in accordance with ASTM F-2231-02a, using a compression molded specimen per ASTM F-1473-01, except that the thickness was 2 mm and the notch depth was 1.5 mm. The temperature at the testing machine was 23° C

PENT (Pennsylvania Notch Test) for Slow Crack Growth ResistanceThe Pennsylvania Notch Test (PENT), a slow crack growth test, was performed, following the procedure described by in ASTM F-1473-01, at 80° C. and 2.4 MPa, unless otherwise specified

Exclusive Properties for PE Pipe

Environmental Stress Crack Resistance (ESCR)The resin environmental stress crack resistance (ESCR) was measured per ASTM-D 1693-01, Method B, with either 10 or 100% Igepal Co-630, or Method C with 100% Igepal. Specimens were molded according to ASTM D 4703-00, Annex A, with a 5 min initial heating period at about 190° C

Minimum Required Strength (MRS) RatingMinimum required strength (MRS) Rating is determined in accordance with ISO 9080, using a 1 inch pipe specimen with standard dimension ratio (SDR=diameter/minimum wall thickness)=11. The pipe specimen is sealed with known internal pressure, and immersed in a water bath at the specified temperature

Trial Strategy

QC will ensure that catalyst activity and yield have achieved the standard, also will record support pore size using BET method

QC will do additional test procedure for bulk density in the powder pre-poly and polymer, full package measurement standard will be conducted

OPS will ensure all parameter in catalyst activation unit refer to catalyst specification, also will record all co-catalyst that been added to the system

OPS will ensure composition during pre polymerization include hydrogen, ethylene, pre poly size and intermediate pre poly silo

Trial Strategy

OPS will ensure that R400 parameter have achieved catalyst guidelines, include gas compose, temperature, STY, residence time, FM, grid temperature, Vf, particle size, co-monomer

Maintenance and Engineering will support all OPS needs in particular for modifying DCS setting

PD will measure all crystal performance from trial polymer compare with Tafmer from Mitsui and Exceed from Exxon as reference include for RCP, Izod & Charpy, ESCR, MRS, tensile test method

TS will conduct customer trial, please concern in particular with swell ratio, additive & pigment mixing, process temperature and back pressure

THANK YOU

this presentation slide is intended in particular for internal discussion only

Introduction to High Molecular Weight Polyethylene