Spontaneous copolymerization of N‐butyl maleimide and ethyl α‐phenyl acrylate with high alternating tendency

Abstract

ABSTRACT:The copolymerization of N-butyl maleimide (BMI) and ethyl ␣-phenyl acrylate (EPA) was successfully carried out without an initiator. A high alternating tendency was observed. The Q, e values were derived by Alfrey-Price equations: Q ϭ 0.09, e ϭ 0.81 for BMI and Q ϭ 0.21, e ϭ Ϫ0.5 for EPA, and the monomer reactivity ratios were r BMI ϭ 0.15 Ϯ 0.01 and r EPA ϭ 0.18 Ϯ 0.08, respectively. In this system BMI was donor and EPA was acceptor. The maximum copolymerization rate and molecular weight appeared at 70 mol % (BMI) in the feed ratio. The spontaneous alternating copolymerization was considered to be completed by a contact-type charge-transfer complex formed by the monomer pairs.

Synthesis and Polymerization of Several New Maleimides Linked to Schiff Bases and Their Copolymers with Acrylonitrile

“…Synthesis of copolymers (13)(14)(15)(16)(17) was performed by following the same procedure steps used in preparation of homopolymers (8-12) except using of equal weights of both Schiff base (3-7) and acrylonitrile which were dissolved together in THF solvent in presence of AIBN initiator. The obtained copolymer was filtered and purified by dissolving in THF followed by precipitation from methanol.…”

“…Thus the prepared maleimide monomers (3-7) were introduced in free radical chain growth copolymerization with acrylonitrile producing new copolymaleimides (13)(14)(15)(16)(17) with new properties [15]. The incorporation of acrylonitrile units in polymeric chains of the new copolymers (13)(14)(15)(16)(17) exhibit them good solubility in most organic solvents but it was noticeable that their softening points in general are higher than those belong to the corresponding homopolymers and this is due to the presence of polar cyano groups(C N) in acrylonitrile units which increased inter chain forces leading to increase softening points.…”

“…The incorporation of acrylonitrile units in polymeric chains of the new copolymers (13)(14)(15)(16)(17) exhibit them good solubility in most organic solvents but it was noticeable that their softening points in general are higher than those belong to the corresponding homopolymers and this is due to the presence of polar cyano groups(C N) in acrylonitrile units which increased inter chain forces leading to increase softening points. Physical properties of copolymers (13)(14)(15)(16)(17) are shown in Table-5 . FTIR spectra of the new copolymers (13)(14)(15)(16)(17) showed very important clear and strong absorption band at(2243cm -1 ) due to (C N) and this is an excellent proof for success of copolymerization reaction [21].…”

“…Details of FTIR spectral data for copolymers (13)(14)(15)(16)(17) are listed in Table-6. Table 6-FTIR spectral data (cm -1 ) of copolymers (13-17) Figure 7-FTIR spectrum of compound (14).…”

“…Thus in the present work we try to improve polymaleimides properties by two ways the first one involved introducing of bulk Schiff base moieties as pendant groups in polymeric chains of polymaleimides ,while the second way involved introducing of maleimides substituted with Schiff bases into copolymerization with acrylonitrile since copolymerization is the most efficient method for modifying polymer properties [14][15][16][17].…”