KALAR® 5281 is a partially cross-linked butyl rubber compound pelletized for easy handling. This product is modified with ethylene vinyl acetate (EVA) copolymer to improve lower temperature toughness and higher temperature processing. KALAR® products feature all the performance attributes expected of butyl rubber. KALAR® 5281 is light amber to yellow in color and is among the tightest cross-linked butyl rubbers of the KALAR® products. It is designed as the starting point for applications that require the maximum resistance to creep and slump.

FunctionBinder, Processing Aid, Impact Modifier

Chemical FamilyButyl Rubber

Compatible Polymers & ResinsButyl Rubber (IIR), Ethylene Propylene Diene Monomer (EPDM)

Enhanced TDS

Identification & Functionality

Chemical Family
CASE Ingredients Functions
Plastics & Elastomers Functions
Relative Degree of Cross-Link

Very High

Features & Benefits

Product Features & Benefits

KALAR® 5281 contains no filler and its tenacity is due to the degree of cross-linking; not reinforcing fillers. This feature permits the compounder the widest formulating latitude. Other key performance benefits include:

  • Elimination of butyl rubber pre-mastication
  • Pellets may be metered to facilitate mixing
  • Requires no vulcanization
  • Readily acceptable in a wide range of solvents
  • Extends with high levels of fillers and plasticizers
  • Compatible with a wide choice of compounding ingredients
  • Compounding economy

Applications & Uses

Application Area
Product Applications

KALAR® 5281 contains no monomeric materials that often impart an objectionable odor and potential instability under elevated temperature. Although widely used in the sealant industry, KALAR® 5281 is also ideal for a variety of other applications.

Properties

Physical Form
Typical Properties
ValueUnitsTest Method / Conditions
Mooney Viscosity (at 127°C)70 - 83ASTM D1646
Specific Gravity0.92ASTM D71
Density7.7lb/galASTM D71
Glass Transition Temperature-65.0°C

Packaging & Availability

Packaging Type
Regional Availability
  • Global (Excluding Russia)
Typical Packaging

KALAR® 5281 is packaged in 48 lb. fiber boxes.

Storage & Handling

Shelf Life
1 Year
Handling
  • The suggested handling procedure varies with the desired product.
  • Coatings and adhesives are produced by adding the pellets to a solvent, mixing with a high-speed homogenizer-dispenser, and adding the rest of the ingredients.
  • Caulks and sealants may be mixed in Sigma blade mixers.
  • Stiff compounds may be mixed in a Banbury or on a two-roll rubber mill.
Storage Conditions
  • KALAR® 5281 product may agglomerate or hard-pack within the boxes, however this will have no effect on chemical or physical properties and the product may be used.
  • Store in a cool, dry environment.