Description

Siloxanes And Silicones, Di-Me, Polymers With Bisphenol A And Carbonic Acid is a specialized polycarbonate-polysiloxane copolymer, identified by CAS No. 68440-78-8. This engineered material combines the high-temperature stability and flexibility of siloxanes with the mechanical strength and clarity of polycarbonate segments derived from bisphenol A. It is essential for formulators and manufacturers requiring advanced materials with enhanced thermal, optical, and impact-resistant properties. Key industries that utilize this high-performance copolymer include medical devices, advanced optics, and specialty engineering plastics.

Application

• High-Performance Thermoplastics: Used as an impact modifier and processing aid in polycarbonate blends to improve ductility and low-temperature performance.
• Medical Device Components: Employed in the manufacture of transparent, biocompatible, and sterilizable parts such as housings, connectors, and lenses.
• Optical Lenses and Films: Serves as a base resin for producing lightweight, scratch-resistant lenses, light guides, and diffuser films with excellent clarity.
• Automotive and Aerospace Interiors: Applied in cockpit displays, interior trim, and functional components requiring a combination of durability, flame retardancy, and weatherability.
• Electronic Encapsulants and Adhesives: Functions as a key ingredient in formulations requiring stable dielectric properties, moisture resistance, and thermal stress relief.
• Specialty Coatings and Films: Used to create hard, transparent coatings with improved gas barrier properties and resistance to yellowing upon UV exposure.

Basic Information

Product Name	Siloxanes And Silicones, Di-Me, Polymers With Bisphenol A And Carbonic Acid
CAS No.	68440-78-8
Molecular Formula	Typically (C15H16O2.C2H6OSi)x - Copolymer
Molecular Weight	Varies by grade and block length. Contact for details.
Synonyms	Polycarbonate-polysiloxane copolymer; Bisphenol A polycarbonate-polydimethylsiloxane block copolymer; PC-PDMS copolymer; Polydimethylsiloxane, polymer with bisphenol A and carbonic acid; Silicone-polycarbonate block copolymer; Poly(bisphenol A carbonate)-block-poly(dimethylsiloxane); Transparent silicone polycarbonate; Lexan® EXL (example trade series)
EINECS	Contact for details.

Quality Control

Our production of polycarbonate-polysiloxane copolymers adheres to stringent quality management systems to ensure batch-to-batch consistency and performance reliability. Each lot is characterized for critical parameters including molecular weight distribution, siloxane block content, thermal stability, and optical clarity. Certificates of Analysis (COA) documenting purity, viscosity, and key functional properties are available upon request. We support compliance with relevant frameworks for industrial and specialized applications.

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). This material is hygroscopic (moisture-sensitive); keep the original container sealed to prevent absorption of atmospheric moisture, which can affect processing and final properties. Keep away from strong acids, bases, and oxidizing agents.

Specification

Item	Specification
Appearance	Colorless to slightly yellow pellets or granules
Identification (IR)	Conforms to structure
Siloxane Content	5% - 20% (Typical range, varies by grade)
Inherent Viscosity	0.40 - 0.70 dL/g (Typical range)
Glass Transition Temperature (Tg)	100°C - 145°C
Moisture Content	< 0.05%
Yellow Index (YI)	< 2.0 (Initial)
Melt Flow Rate	5 - 25 g/10 min (300°C/1.2 kg)

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