Description

(Phenylsilsesquioxane)-(Dimethylsiloxane) Copolymer is a high-performance hybrid silicone resin that combines the thermal stability and rigidity of a silsesquioxane cage structure with the flexibility and processability of a siloxane chain. This unique architecture makes it a critical material for enhancing the thermal, mechanical, and dielectric properties of advanced composites and coatings. It is essential for formulators and manufacturers in the aerospace, electronics, and high-temperature plastics industries seeking to push the boundaries of material performance.

Application

• High-Temperature Resin Modifier: Used as an additive or co-polymer in polyimide, epoxy, and cyanate ester resins to significantly improve heat resistance, dimensional stability, and glass transition temperature (Tg).
• Electronic Encapsulants & Underfills: Provides excellent dielectric properties, low moisture absorption, and thermal stress relief for protecting sensitive microelectronics and semiconductor devices.
• Advanced Composite Matrices: Serves as a matrix resin or toughening agent for carbon fiber and glass fiber composites in aerospace and automotive applications requiring lightweight, strong, and heat-resistant components.
• Protective & Release Coatings: Formulated into high-performance coatings that offer exceptional thermal oxidative stability, water repellency, and non-stick properties for industrial and consumer goods.
• LED Encapsulation: Utilized in optical-grade formulations for LED packaging due to its high transparency, good light stability, and ability to withstand high operating temperatures.
• Adhesive & Sealant Formulations: Imparts enhanced heat resistance and durability to specialty silicone and organic polymer-based adhesives and sealants.

Basic Information

Product Name	(Phenylsilsesquioxane)-(Dimethylsiloxane) Copolymer
CAS No.	73138-88-2
Molecular Formula	(C6H5SiO1.5)x[(CH3)2SiO]y
Molecular Weight	Varies by x:y ratio (Contact for details)
Synonyms	Phenyl T-Structure Silicone; Phenylsilsesquioxane-Dimethylsiloxane Block Copolymer; Phenyl Polyhedral Oligomeric Silsesquioxane-co-Dimethylsiloxane; POSS-DMS Copolymer; Phenyl POSS-Silicone Hybrid; Polyphenylsilsesquioxane-co-polydimethylsiloxane; PDMS-Phenyl POSS Copolymer
EINECS	Contact for details

Quality Control

Our (Phenylsilsesquioxane)-(Dimethylsiloxane) Copolymer is manufactured under a strict quality management system. Each batch undergoes rigorous analytical testing to ensure consistency in key parameters such as molecular weight distribution, phenyl content, and viscosity. Certificates of Analysis (COA) detailing these specifications are provided with every shipment to guarantee reliable performance in your formulations.

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 acids, bases, and oxidizing agents. Under these conditions, the product is stable for extended periods.

Specification

Item	Specification
Appearance	Colorless to pale yellow viscous liquid or solid
Identification (IR)	Conforms to structure
Phenyl Content	30 - 70 wt% (Grade dependent)
Viscosity (25°C)	100 - 100,000 cSt (Grade dependent)
Weight Average Molecular Weight (Mw)	1,000 - 50,000 g/mol (Grade dependent)
Volatiles	< 2.0%

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