Search results for "Step-growth polymerization"
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Step growth polymerization via tandem ene and diels-alder reactions
1997
In contrast to other electron deficient enophiles or dienophiles which react with 1,4-cyclohexadiene (1,4-CHD) under aromatization, 1,2,4-triazoline-3,5-diones react in a defined reaction sequence. In a first step the 1,4-cyclohexadiene reacts via an ene-reaction. The intermediately formed substituted 1,3-cyclohexadiene immediately reacts in a Diels-Alder reaction. The regiochemistry of the Diels-Alder reaction is controlled by the solvent polarity. This reaction sequence can be used to synthesize polymers. Low-molar-mass model compounds were synthesized to elucidate the stereochemistry of the polymers. By varying the bistriazolinedione, polymers with backbones of different rigidity are ava…
Step-growth Polymerization ofBistriazolinediones with1,1-Diphenylethylene
1996
The reactions of 4-ethyl-1,2,4-triazoline-3,5-dione (ETD) (1) and 4-phenyl-1,2,4-triazoline-3,5-dione (PhTD) (2) with 1,1-diphenylethylene (DPE) (3) were investigated at room temperature. The reactions are very fast and are completed in less than 4 min. These reactions lead to the formation of two 2 :1 adducts via double Diels-Alder and Diels-Alder-ene reactions in a ratio of 1.35 : 1. The structure of these adducts where R = Et were determined by X-ray analysis of a single crystal. These compounds were used as models for the polymerization reactions. The reaction of bistriazolinediones (1,6-bis-(3,5-dioxo-1,2,4-triazoline-4-yl)hexane and bis-(p-3,5-dioxo-1,2,4-triazoline-4-ylphenyl)methane…