Description

Methyl Phenyl Silsesquioxanes-Dimethyl, Diphenyl Siloxane Polymers are a class of advanced hybrid inorganic-organic polymers, specifically silsesquioxane-siloxane copolymers, known for their exceptional thermal stability, optical clarity, and versatile rheological properties. These materials are engineered to bridge the performance gap between traditional silicones and rigid silica, offering a unique combination of processability and high-temperature resistance. They are critical for formulators and manufacturers in the electronics, aerospace, and high-performance coatings industries seeking to enhance material durability and functionality.

Application

• As a high-temperature resin modifier and crosslinking agent in advanced thermoset composites for aerospace and automotive components.
• Key ingredient in LED encapsulants and optical materials, providing excellent light transmission and long-term thermal/UV stability.
• Used as a performance additive in high-temperature resistant coatings and paints, improving weatherability and gloss retention.
• As a dielectric material and stress buffer in microelectronic packaging and underfill applications.
• Base polymer for formulating specialty greases and lubricants that must perform under extreme thermal and oxidative conditions.
• Reinforcing filler and compatibilizer in engineering plastics (e.g., PEEK, polyimide) to enhance mechanical and thermal properties.
• Precursor for synthesizing hybrid sol-gel coatings with tailored surface properties (hydrophobic, anti-fouling).

Basic Information

Product Name	Methyl Phenyl Silsesquioxanes-Dimethyl, Diphenyl Siloxane Polymers
CAS No.	68440-64-2
Molecular Formula	(C7H8O1.5Si)x[(CH3)2SiO]y[(C6H5)2SiO]z
Molecular Weight	Varies by composition (Contact for details)
Synonyms	Methyl Phenyl Silsesquioxane-Dimethyl Diphenyl Siloxane Copolymer; Phenylmethylsilsesquioxane-Dimethylsiloxane-Diphenylsiloxane Copolymer; MPS-DMDP Copolymer; Silsesquioxane-Siloxane Hybrid Polymer; Polyphenylmethylsilsesquioxane-co-polydimethylsiloxane-co-polydiphenylsiloxane; Phenyl T-Resin Modified Silicone; Hybrid Silicone Resin; CAS 68440-64-2
EINECS	Contact for details

Quality Control

Our production of Methyl Phenyl Silsesquioxanes-Dimethyl, Diphenyl Siloxane Polymers adheres to a strict quality management system. Each batch is characterized for critical parameters including molecular weight distribution, phenyl content, viscosity, and thermal stability to ensure consistent performance. Certificates of Analysis (COA) detailing these specifications are provided with every shipment. We support compliance with relevant global regulatory frameworks, including REACH.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at room temperature (15-25°C). Keep away from strong oxidizing agents. Under these conditions, the product is stable for extended periods. For long-term storage beyond one year, evaluation of key properties is recommended prior to use.

Specification

Item	Specification
Appearance	Colorless to pale yellow viscous liquid or solid
Phenyl Content (by 1H-NMR)	20 - 50% (Grade dependent)
Viscosity (25°C)	100 - 100,000 cSt (Grade dependent)
Weight Average Molecular Weight (Mw)	1,000 - 20,000 g/mol (GPC)
Volatiles (150°C, 1h)	≤ 2.0 %
Thermal Decomposition Onset (TGA)	> 400 °C
Refractive Index (nD25)	1.45 - 1.55

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