Benzocyclobutene-functionalized hyperbranched polysiloxane for low-k materials with good thermostability

Area of Science:

• Polymer Chemistry
• Materials Science
• Organic Synthesis

Background:

• Hyperbranched polysiloxanes offer unique properties but are limited by low glass transition temperatures.
• Developing high-performance polymers with enhanced thermal and dielectric properties is crucial for advanced electronic applications.

Purpose of the Study:

• To synthesize benzocyclobutene-functionalized hyperbranched polysiloxane (HB-BCB).
• To investigate the thermal, mechanical, and dielectric properties of the cured HB-BCB resin.
• To evaluate its potential as a low-k material with high thermal stability.

Main Methods:

• Piers-Rubinsztajn reaction for HB-BCB synthesis.
• Curing of the resin at temperatures >200 °C.
• Characterization using NMR (¹H, ¹³C, ²⁹Si), DSC, DMA, and TGA.

Main Results:

• Successful synthesis of HB-BCB and formation of a crosslinked thermoset resin.
• High thermal decomposition temperature (T_d5 = 512 °C) and good high-temperature mechanical properties.
• Low dielectric constant (k = 2.70 at 1 MHz) and low dissipation factor (2.13 × 10⁻³ at 1 MHz).

Conclusions:

• The prepared resin functions as a low-k material with excellent high-temperature performance.
• Introduction of benzocyclobutene (BCB) groups and highly crosslinked structure significantly enhance siloxane performance.
• The developed material shows promise for applications requiring both low dielectric properties and thermal stability.