Description

Isobutylene-p-Methylstyrene Copolymer is a synthetic elastomer known for its excellent thermal stability, chemical resistance, and low gas permeability. This copolymer is engineered to provide superior performance in demanding sealing and barrier applications where standard rubbers may fail. It is a critical material for manufacturers in the automotive, pharmaceutical packaging, and industrial hose and belt sectors seeking durable, reliable polymer components.

Application

• Pharmaceutical Packaging: Used as a primary component in elastomeric closures (stoppers) and seals for vials and syringes due to its excellent barrier properties and compatibility.
• Automotive Seals and Gaskets: Ideal for dynamic and static seals, O-rings, and gaskets in engines and fuel systems, offering resistance to heat, ozone, and various fluids.
• Industrial Hose and Belting: Serves as a key polymer in hoses for chemical transfer and in conveyor belts requiring high durability and low permeability.
• Adhesive and Sealant Formulations: Acts as a tackifier and base polymer in high-performance adhesives and construction sealants, enhancing elasticity and weather resistance.
• Wire and Cable Insulation: Provides a protective, insulating layer for cables, offering good electrical properties and environmental resistance.
• Oil and Gas Industry Components: Utilized in gaskets, packers, and other downhole tools where resistance to sour gas (H2S) and high temperatures is required.

Basic Information

Product Name	Isobutylene-p-Methylstyrene Copolymer
CAS No.	61128-14-1
Molecular Formula	(C4H8)x(C9H10)y
Molecular Weight	Varies by grade (Typical Mw: 50,000 - 500,000 g/mol)
Synonyms	Poly(isobutylene-co-p-methylstyrene); p-Methylstyrene-isobutylene Copolymer; Isobutylene/4-Methylstyrene Copolymer; Brominated Isobutylene-co-p-Methylstyrene (BIMSM); Exxpro™ (Trade Name); Butyl Rubber Derivative; p-Methylstyrene Modified Butyl Rubber; Isobutylene-4-Methylstyrene Elastomer
EINECS	Contact for details

Quality Control

Our Isobutylene-p-Methylstyrene Copolymer is manufactured under a strict quality management system. Each batch undergoes rigorous testing for key parameters including molecular weight distribution, p-methylstyrene content, and bromine content (if brominated). We ensure compliance with relevant industry standards for elastomers. Certificates of Analysis (COA) documenting purity, physical properties, and performance characteristics are available upon request.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at room temperature (15-25°C). Keep away from strong oxidizing agents and sources of heat or ignition. For long-term storage, maintain under inert atmosphere (e.g., nitrogen) to prevent oxidation.

Specification

Item	Specification
Appearance	Off-white to light amber solid (crumb, slab, or pellet)
Identification (IR)	Conforms to structure
p-Methylstyrene Content	3.0 - 12.0 % (Grade dependent)
Bromine Content (if applicable)	0.5 - 2.0 % (Grade dependent)
Mooney Viscosity (ML 1+8 @ 125°C)	30 - 70
Volatile Matter	≤ 1.0 %
Ash Content	≤ 0.5 %

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.