Synthesis of ω-Pentadecalactone Copolymers with Independently Tunable Thermal and Degradation Behavior

Abstract

ω-Pentadecalactone (PDL) was copolymerized with lactones of varying sizes (6-, 7-, 9-, and 13-membered rings) in order to characterize the properties of PDL copolymers throughout the lactone range for copolymerizations catalyzed by magnesium 2,6-di-tertbutyl-4-methylphenoxide (Mg(BHT) 2 (THF) 2 ). Kinetics of the copolymerization reactions were studied using quantitative 13 C NMR spectroscopy, which revealed that the polymerization of the smaller, strained lactone monomer occurred rapidly before the incorporation of PDL into the polymer. Furthermore, all polymers were randomly sequenced as a consequence of transesterification side reactions that occurred throughout polymerization. The copolymers were all shown to cocrystallize to produce polymers with melting and crystallization temperatures that displayed a linear relationship with respect to monomer ratio. Differences in degradation behavior of the smaller lactones enabled the synthesis of PDL copolymer materials that displayed independently controllable thermal and degradation properties.

Switching from Controlled Ring-Opening Polymerization (cROP) to Controlled Ring-Closing Depolymerization (cRCDP) by Adjusting the Reaction Parameters That Determine the Ceiling Temperature

“…5−7 These polymers, which are most often obtained by ring-opening polymerization of the respective cyclic monomers, allow, through different addition schemes or inherent reactivity behavior, the construction of refined macromolecular architectural features. 8−10 This enables control of many polymer properties, such as degradation, 11−13 mechanical performance, 11,14 and the placement of functional groups along the polymer chain. 15,16 …”

Amphiphilic block copolymer self‐assemblies of poly(NVP)‐b‐poly(MDO‐co‐vinyl esters): Tunable dimensions and functionalities

“…PNIPAAm and PNVP are commonly synthesized by radical polymerization as a consequence of the nonconjugation of their amide ketone group with the vinyl group . To diversify the range of properties targeted for the biodegradable hydrophobic block, much effort has recently been focused on the addition of functional groups on the PCL or PDLLA polymer backbone by either synthesis of new functional ε‐CL and d , l ‐lactide monomers, chain‐end modifications via the incorporation of functional groups in the ROP initiator or by copolymerization of CL and d , l ‐lactide with other monomers . While all approaches have so far been successful in achieving incorporation of further functionalities, they have been shown to be limited as a consequence of arduous steps during functional monomer synthesis, poor functional group compatibilities, and/or a poor match in monomer reactivity ratios .…”

Dialkylmagnesium‐Promoted Deprotonation of Protic Precursors for the Activated Anionic Ring‐Opening Polymerization of Epoxides

“…Alcohols with different steric bulk and acidity, including iPrOH, PhCH 2 OH, Ph 2 CHOH, and Ph 3 COH, were employed with Bu 2 Mg to form magnesium alkoxides. The generated system was shown to improve the polymerizability of cyclic esters in dilute solutions by increasing the molar masses and narrowing the dispersity values where alcohols acts as control transfer agents …”