Synthesis and characterization of platinum(II) loaded thermosensitive poly(vinyl ether)s and investigations into their potential as UV-triggerable hydrosilylation catalysts

Ansar, Muhammad Hamza

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https://hdl.handle.net/2142/122218 Copy

Description

Title

Synthesis and characterization of platinum(II) loaded thermosensitive poly(vinyl ether)s and investigations into their potential as UV-triggerable hydrosilylation catalysts

Author(s)

Ansar, Muhammad Hamza

Issue Date

2023-12-05

Director of Research (if dissertation) or Advisor (if thesis)

Girolami, Gregory S

Department of Study

Chemistry

Discipline

Chemistry

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Hydrosilylation reaction catalysis
• Thermosensitive polymers
• UCST behavior
• Pt catalysis

Abstract

The hydrosilylation reaction, which involves the addition of silane Si-H bonds across C-C and C-O multiple bonds, has numerous applications in chemistry. These applications range from the synthesis of organosilicon reagents to the production of silicone-based elastomers. In industry, Karstedt’s catalyst is the most widely employed hydrosilylation catalyst, but it is highly active at room temperature, which for some applications the high activity is not desirable. In addition, it suffers from a short shelf life and is stable only in solution. The aim of the present study is to develop a new kind of hydrosilylation catalyst which has a long shelf life in its latent form but catalyzes the reaction at a high rate after a thermal trigger is applied. In order to achieve this goal, we focus on the chemistry of poly(vinyl ether)s, some of which have been reported to exhibit a thermosensitive phenomenon called upper critical solution temperature (UCST). UCST behavior refers to the property that the polymer is insoluble in a certain solvent at low temperatures, but becomes completely soluble over a very small temperature increase. In this study, we studied as heat-triggerable hydrosilylation catalysts Pt-loaded poly(vinyl ether)s that exhibit UCST behavior in organic solvents. In the first chapter, we document the synthesis of a poly(vinyl ether) with biphenoxyethyl pendants, called BPOVE, which is known to be insoluble in toluene below 15 oC. We modified BPOVE to incorporate pyridine functionalities (NBPOVE), studied the thermosensitive behavior of the resulting modified polymer. We then loaded the modified polymer with Pt(II) and studied its catalytic activity for the hydrosilylation of 1-octene with MD´M as a function of temperature. The second chapter describes the synthesis of poly(vinyl ether)s with nonafluoroheptanoxyethyl side chains, called 9FVE, which have been reported to be insoluble in toluene below 70 oC. We modified 9FVE to incorporate pyridine functionalities (N9FVE) and studied its solubility in toluene as a function of temperature.

Graduation Semester

2023-12

Type of Resource

Thesis

Copyright and License Information

Copyright 2023 Muhammad Hamza Ansar

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