In this study, condensation polymerization was used to synthesize a number of novel liquid crystal polymers with 1,3,4-oxadiazole rings based on melamine. The new synthesized polymers were characterized by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1HNMR) spectroscopy. Differential scanning calorimetry (DSC) and optical polarization microscopy (OPM) were used to investigate their liquid crystalline properties. The results demonstrated that throughout a wide temperature range, most of the polymers exhibited columnar (CohX) and nematic (N) liquid crystalline phases.
By condensation of benzaldehyde with thiourea in absolute ethanol in the presence of glacial acetic acid as a catalyst, the Schiff base(1-benzylidenethiourea)[I] was synthesized by synthesis of 4-(3-benzylidenethioureido)-4-thioxobut-2-enoic acid compound[II] by reaction of maleic anhydride with schiff base [I] in DMF. When treating compound [II] with ammonium persulfate (NH4)2S2O8 (APS) as an ethanol initiator to obtain polymer [III], compound [III] reacted to polymer [IV] with SOCl2 in benzene. Sulfamethizole, celecoxib, salbutamol, 4-aminoantipyrine to yield polymers [V-VIII], compound [IV] reaction with different drugs. Spectral evidence established the structure of synthesized compounds: FTIR an
The new compounds synthesized by sequence reactions starting from a reaction of 4-hydroxybenzaldehyde with 1,5-dibromo pentane to produce dialdehyde)I( .Then compound )I( reacted with different aromatic amines to give schiff bases )IIIV(,thereafter added acetyl chloride to schiff bases to yield N-acyl derivatives)VVII(.While1,3-diazetine derivatives)VIII-X( were synthesized from the reaction of N-acyl derivatives with sodium azide.The reaction of thiourea with N-acyl compounds led to formation of thiourea derivatives (XI-XIII).Finally, the pyrimidine compounds )XIV-XVI( were synthesized by ring closure reaction of compounds(XIXIII) with diethyl malonate.The synthesized compounds were characterized by measurements of melting points,FTIR,1H-N
... Show MoreThis paper deals with the preparation of new monomers and polymers which including heterocyclic unit. The diacid chlorides compounds [1-3] were prepared from the reaction of glutaric acid, adipic acid, terephthalic acid with thionyl chloride. Succinic acid reacted with ethanol to produce compound [4]. Compound [4] reacted with hydrazine hydrate to obtain succinic hydrazide [5].Compound [5] reaction with CS2 and KOH in absolute ethanol to produce compound [6].The polymers [7-12] have been created by reacting diacid chlorides compounds [1-3] with compound[5] or [6] in dry pyridine with some drops of DMF. The topology of produced compounds has characterized through their spectral and analytical data as in FT-IR spectra, Thermal analysis [DSC,
... Show MoreA novel series of liquid crystalline compounds containing 2,4-thiazolidinedione units with varying terminal alkyl chain lengths was successfully synthesized and characterized. The chemical structures of the synthesized compounds were confirmed by FT-IR, ¹H-NMR, and mass spectrometry. The mesomorphic behavior was investigated using polarized optical microscopy (POM) and differential scanning calorimetry (DSC). Compounds [V]₄, [V]₅, and [V]₆ exhibited enantiotropic nematic phases, while compound [V]₈ displayed a smectic A (SmA) phase. No liquid crystalline behavior was observed for compound [V]₃. The liquid crystalline properties were found to depend on the terminal-to-lateral chain length ratio, molecular geometry, and the nature
... Show Moreالهدف من الدراسه تحضير فئه جديده من بوليمرات السليكون P1-P4 والتي تمت على اساس استحدام ثنائي مثيل ثنائي كلورو سيلان((DCDMS مع بعض المركبات العضويه التي تحتوي مجاميع الهيدروكسيل الطرفيه والتي حضرت لاول مره M1-M4، بأستخدم البلمره التكثيفيه .كما تم تحضير متراكباتها النانويهP′1-P′4 بوجود جسيمات الفضه النانويه (Ag-NPs) باستخدام طريقة صب المحاليل. شخصت جميع التراكيب للمونمرات والبوليمرات المحضره باستخدام مطيافية
... Show MoreMany new heterocyclic compounds including 4-thiazolidinones containing indole with triazole units were described. The new Schiff bases [VII] a, b and [VIII] a, b synthesized by condensation acid hydrazides [II],[VI] with different (aromatic) aldehydes in absolute ethanol. The refluxing equimolar amounts of the Schiff bases ([VII] a, b,[VIII] a, b) with thioglycolic acid in benzene led to get thiazolidin-4-ones derivatives ([IX] a, b and [X] ad). Finally, the new derivatives [XI] ac run out via the reacted compound [IX] a with different n-alkyl bromide (methyl bromide, ethyl bromide, and butyl bromide)
Many new heterocyclic compounds including 4-thiazolidinones containing indole with triazole units were described. The new Schiff bases [VII]a, b and [VIII]a,b synthesized by condensation acid hydrazides [II],[VI] with different (aromatic) aldehydes in absolute ethanol. The refluxing equimolar amounts of the Schiff bases ([VII]a,b, [VIII]a,b) with thioglycolic acid in benzene led to get thiazolidin-4-ones derivatives ([IX]a,b and [X]a-d). Finally, the new derivatives [XI]a-c run out via the reacted compound [IX]a with di