Untersuchungen zur linearen thiol‐en‐photopolymerisation

Abstract

The photoinitiated free-radical polymerization of 3,6-dioxa-1.8-octanedithiol and bis(ally1) hydroquinone ether or ethylene glycol divinyl ether leads to poly(thi0ethers) having antiMarkomikov structure with number-average molar mass M,,: 14000, 12000 g/mol, respectively. The chain propagation is limited by &sulfide production (nearly 3%) and cycle production (nearly 4%). Differential scanning calorimetry (DSC) investigations showed that the rate of polymerization decreases in the series vinyl ether ally1 ether > 1-alkenc The influence of the dithiol structure @hercapto ether, thioglycolate, aliphatic thiols) is not dominant.

Fatty Acid Derived Monomers and Related Polymers Via Thiol‐ene (Click) Additions

“…[18] Nevertheless, already early on it was discovered that dithiols and dienes are suitable monomers for polymer synthesis. [19] More recent investigations have shown that quite high molecular weight polythioethers can be obtained in that way, [20] that initiators are not necessary for the reaction to proceed, [21] but radical inhibitors suppress the polymerization for some time. [21] Today, the reaction is used in the sense of a click reaction for the synthesis of dendrimers, [22] the grafting of side-groups to reactive polymers, [23,24] or the synthesis of star polymers.…”

Synthesis of polymers with an intact lactone ring structure in the main chain

“…The photoinitiated polyaddition of thiols with compounds containing carbon-carbon double bonds is a well-known reaction 7,8) . Starting with model experiments, we used octylthiol (7) as monofunctional thiol in order to get information on the reactivity of the different olefinic bonds in 1.…”

New polymers with coronand structure

“…We are interested in the extension of this Diels-Alder reaction of bispyrones and bismaleimides in connection with our investigations on the synthesis of alternating copolymers by polyaddition reactions, applicable as new polymer materials for optical applications2, 3). Such examples are not described in the literature.…”

“…mol) of bispyrone 4 and 1,12 g (3,51 . The solid product was isolated and chromatographed on a silica-gel column with toluene/acid ester (vol.…”