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Dielectric Properties of Functional Polypropylene and Derivatives

Dielectric Properties of Functional Polypropylene and Derivatives. Xuepei Yuan, Min Zhang, and Mike Chung Department of Materials Sci. & Eng. Penn State University. BOPP Dielectric ( s -electron polarization ). Advantages and Disadvantages. e = 2.2. High breakdown strength

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Dielectric Properties of Functional Polypropylene and Derivatives

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  1. Dielectric Properties of Functional Polypropylene and Derivatives • Xuepei Yuan, Min Zhang, and Mike Chung • Department of Materials Sci. & Eng. • Penn State University

  2. BOPP Dielectric (s-electron polarization) Advantages and Disadvantages e = 2.2 • High breakdown strength • Low dielectric loss • Good processibility • Self-healing and low cost • Low dielectric constant • Low energy density P-E loops Simultaneously • Increase dielectric constant • Increase breakdown strength • Maintain low energy loss

  3. Functional Polypropylene and Derivatives Dipolar, Ion Pair, or p-Electrons with Good Polarization Reversibility

  4. Synthesis of Functional Polypropylene /MAO

  5. PP-H Copolymers PP Flexible alkyl side chains reduce crystallinity, increase irreversible polarization

  6. PP-OH Copolymers Steven Boggs Bob Weiss Fast and Reversible polarization Unexpected large increase in dielectric constant with few% OH groups

  7. PP-OH Derivatives Nonpolar X-linking with p-electrons Ion pair

  8. PP-OSi(CH3)3 Derivative With 4 mol% side chains Silane group removes H-Bonding and reduces e and polarization reversibility

  9. Comparison of PP-H and PP-OSi(CH3)3 With 4 mol% side chains • Flexible side chains reduce crystallinity and polarization reversibility. • H-bonding is needed for reversible polarization.

  10. Cross-linking PP-OH Derivative Gel=100% [OH]=0.6 mol%

  11. PP-O-Na+ Ion-containing Polymer • Ion pair (O-M+) increases polarization (e). • Ion pairs show non-linear polarization and large remnant polarization. • Ion pairs may form ionic cluster (with water?) that slowly reorganize its structure under the electric field.

  12. PP-O-Na+ and PP-O-K+ Ion-containing Polymers PP-O-Na+ PP-O-K+

  13. Brief Summary • Few % OH groups in flexible side chains is sufficient to double PP dielectric constant (e). • 3-D network, either chemical or physical cross-linking by side chains, is essential to exhibit reversible (fast) polarization response. • Ion-containing polymer PP-O-Na+ increases dielectric constant, but reduces the responding speed and creates ferroelectric loss. Other polar groups that can form H-bonding and also ionic pairs. What are the unique features of flexible side chains under the electric field?

  14. Dielectric Properties of PolyalcoholsHomopolymer Rampi Ramprasad Unexpected large dielectric constant and loss

  15. P-E Loops of Polyalcohol Hompolymers 10 Hz Large Ferroelectricity

  16. PP-COOH Copolymers Dielectric Constant P-E loop C1: [COOH]=0.51% C2: [COOH]=0.80% C3: [COOH]=1.13% Overall, PP-COOH results are quite in consistence with PP-OH results

  17. PP-NH2 Copolymers PP-NH2 (2.2%) PP-NH2, 2.2% PP PP Overall, PP-NH2 results are also consistent with PP-OH results

  18. Comparison of PP-NH2 and PP-NH3+Cl- Copolymers

  19. P-E Loop Comparison PP-NH2 (with 0.4 mol% NH2) PP-NH2 (with 1.4 mol% NH2) PP-NH3+Cl- (with 0.4 mol% NH3+Cl-) PP-NH3+Cl- (with 1.4 mol% NH3+Cl-) Ionization of NH2 to NH3+Cl- increases e and slightly reduces the polarization reversibility

  20. Conclusion • Synthesis routes have been developed to prepare a broad range of functional PP polymers and derivatives. • PP-OH, PP-NH2, and PP-COOH copolymers, with few % of polar groups form H-bondings and 3-D network, which increase dielectric constant and reversible polarization (low loss). (breakdown strength?) • Poly(hexenol) homopolymer shows unexpected high dielectric constant and large remnant polarization (large ferroelectricity). • PP ion-containing copolymers show mix dielectric behaviors, PP-NH3+Cl- with fast response, PP-O-Na+with slow response

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