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A novel series of main chain liquid crystalline copolyesters with X-shaped two-dimensional mesogenic unit and crown ether cycle of cis-4,4′-bis(4-hydroxyphenylazo) dibenzo-18-crown-6 was prepared via solution condensation polymerization from 4,4′-(α,ω-hexanedioyloxy) dibenzoyl dichloride (M₁), 2,5-bis(p-octyloxybenzoyloxy) hydro-quinone (M₂) and cis-4,4′-bis(4-hydroxyphenylazo) dibenzo-18-crown-6 (M₃). Monomer M₁ was synthesized by esterification and substitution of adipoyl chloride with p-hydroxybenzoic acid, monomer M₂ was synthesized by esterfication and reduction reaction of 2,5-dihydroxybenzoquinone and p-octanoxybenzoyl chloride and monomer M₃ was synthesized by diazotization and coupling reaction of cis-diaminodibenzo-18-crown-6 with phenol. The molecular weights of copolyesters are not high, and the intrinsic viscosity [η] of copolyesters ranges from 0.25–0.35. The monomers' structures were identified by using elemental analysis, IR, UV, ¹H-NMR, MS, etc. All the copolyesters are yellowish powders and insoluble in THF and CHCl₃ at room temperature except CP9. The properties of copolyesters were investigated by using GPC, [η] , DSC, TG, WAXD and POM. It was found that all the copolyesters entered into liquid crystal phase when they were heated to above their melting temperature (T_m). The typical smectic and nematic phase texture can be observed on POM. Their mesophase transition temperature and thermal stability change regularly with varying the content of cis-4,4′-bis(4-hydroxyphenylazo) dibenzo-18-crown-6 unit in the copolyesters.

A series of polymeric complexes were prepared from Fe²⁺, Co²⁺ or Ni²⁺ and poly(Schiff base) (DAPcIPA), which was obtained by polycondensation of 5,6-diamino-1,10-phenanthroline (DAP) with isophthalaldehyde (IPA). The structures of the polymer and the polymeric complexes were characterized by IR, ¹H-NMR and elemental analysis. The magnetic behavior of these complexes was measured as a function of magnetic field strength (0–3.98 × 10⁶A/m) at 5 K and as a function of temperature (5–300 K) at a magnetic field strength of 2.39 × 10⁶A/m. Experimental results show that DAPcIPA-Ni²⁺, DAPcIPA-Co²⁺ are soft ferromagnets while DAPcIPA-Fe²⁺ exhibits features of an antiferromagnet.

New Schiff base polymers poly[4,4′-methylenebis(cinnamaldehyde)ethylenediimine] (PMBCen), poly[4,4′-methylenebis(cinnamaldehyde)1,2-propylenediimine] (PMBCPn), poly[4,4′-methylenebis(cinnamaldehyde)1,3-propylenediimine] (PMBCPR), poly[4,4′-methylenebis(cinnamaldehyde)1,2-phenylenediimine] (PMBCPh), poly[4,4′-methylenebis(cinnamaldehyde)meso-stilbenediimine] (PMBCS), poly[4,4′-methylenebis(cinnamaldehyde)urea] (PMBCUR), poly[4,4′-methylenebis(cinnamaldehyde)semicarbazone] (PMBCSc), poly[4,4′-methylenebis(cinnamaldehyde)thiosemicarbazone] (PMBCTSc) and poly[4,4′-methylenebis(cinnamaldehyde)hydrazone] (PMBCH) were formed by polycondensation of 4,4′-methylenebis(cinnamaldehyde) with ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,2-phenylenediamine, meso-stilbenediamine, urea, semicarbazide, thiosemicarbazide and hydrazine, respectively. The dialdehyde and polymers have been characterized through elemental micro-analysis, IR, UV-Vis and ¹H-NMR spectroscopic techniques. Thermoanalytical studies and viscous flow of dilute solutions of dialdehyde and its polymers have been examined and compared.

A novel series of liquid crystalline copolyesters with T-shaped two-dimensional mesogenic unit and crown ether cycle of cis-4,4′-bis(4-hydroxyphenylazo)dibenzo-18-crown-6 was prepared via solution condensation polymerization from 4,4′-(α,ω-hexanedioyloxy)dibenzoyl dichloride (M₁), 2-(4′-ethoxyphenyl)hydroquinone (M₂) and cis-4,4′-bis(4-hydroxyphenylazo)dibenzo-18-crown-6 (M₃). The molecular weights of copolyesters are not high, and the intrinsic viscosity [η] of copolyesters ranges from 0.29–0.43. The monomers' structures were identified by elemental analysis, IR, UV, ¹ H-NMR, MS, etc. All the copolyesters are yellowish powders and insoluble in THF and CHCl₃ at room temperature except CP-9. The properties of copolyesters were investigated by using GPC, [η], DSC, TG, WAXD and POM. It was found that all the copolyesters entered into liquid crystalline phase when they were heated to above their melting temperature (T_m). The threaded texture and schlieren texture of nematic phase can be observed on POM. Their T_m and isotropic temperature (T_i) decrease gradually, while thermal stability increase with varying the content of T-shaped two-dimensional mesogenic unit in the copolyesters.

Two series of aromatic-aliphatic random copolyesters (PEBTOXS) with diverse diol ratios have been synthesized by direct melting polycondensation. Two kinds of diols (glycol (EG) and 1,4-butanediol (BD)) are used in combination in order to adjust crystallization and tensile properties, and three kinds of diacids (dimethyl terephthalate (DMT), diethyl oxalate (DEOX), and sebacic acid (SA)) are involved. ¹H-NMR spectra quantify both composition and structure, and show that the final contents in copolyesters appropriate to the feed ratio. Average sequence lengths of six polyester units are calculated based on the analyses of ¹H-NMR spectra and copolyester structure. The results reveal that the average sequence lengths of sebacate related units increase with the increasing content of sebacic acid in copolyesters, while those of oxalate related units show a slight rise. Decreases of average sequence length are found for all terephthalate units, which may be because of the restriction of rigid aromatic units in reactions.

Glycolic acid was polymerized under vacuum in the presence and absence of nano sized clay. The added clay catalyzed the condensation polymerization which can be confirmed by recording FTIR spectroscopy and intrinsic viscosity (IV) values. The relative intensity of C=O/CH is increased while increasing the amount of clay. DSC showed the appearance of multiple endotherms of poly(glycolic acid). TGA showed the percentage weight residue remain above 750°C for polymer-nano composite system was 21% and hence proved the flame retardancy (char forming) nature. TEM confirmed the nano size of the clay used to catalyze the condensation reaction. The intrinsic viscosity value was increased with the increase of percentage weight of Hectorite type clay.

Direct melt/solid polycondensation of lactic acid (LA) was carried out to obtain high molecular weight poly(lactic acid) (PLA) by a process using various catalysts in the first-step melt polycondensation, and followed solid polycondensation by using p-toulenesulfonic acid monohydrate (TSA) as the catalyst in the second step. Effects of various catalysts and reaction temperature on the molecular weight and crystallinity of resulting PLA polymers were examined. It was shown that SnCl₂·2H₂O/TSA, SnCl₂·2H₂O/succinic anhydride, and SnCl₂·2H₂O/maleic anhydride binary catalysts should be effective binary catalysts to obtain high molecular weight PLA of more than 1.2 × 10⁵. A conventional melt spinning method was used to spin PLA fibers, which displayed tensile strength of (382.76 ± 1.41) MPa and tensile modulus of (4.36 ± 0.07) GPa.

A novel kind of hexa-armed fluorene-benzene copolymer based on a hexaazaisowurtzitane core was synthesized through Suzuki coupling polycondensation. The introduction of this bulky caged-core could not only enhance the photoluminescence quantum efficiency, but also improve the electroluminescence properties, especially suppress the common green-color emission of polyfluorenes (PFs) material during device operation. These features can be attributed to the successful suppression of PF's chain aggregation which profits from the introduction of the bulky hexaazaisowurtzitane core and the design of multi-armed architecture.

A series of novel hybrid photoinitiators (YPhCOPhXPhI⁺PhPF₆^–, Y = 4-NO₂, 4-MeO or 3-Cl, X = O, OCH₂, or nothing), which contain multiple aromatic rings (PhCOPhXPh), were prepared by reaction of easily available aryl ketones (YPhCOPhXPh) with iodosobenzene diacetate [PhI⁺OCOCH₃ (CH₃CO₂)^–]. The inset of an aromatic ring into p-benzoyldiphenyliodonium hexafluorophophate ((YPhCOPhXPhI⁺PhPF₆^–) (BDPIH, He-type photoinitiator) between diphenyliodonium and benzoyl is propitious both to the preparation and the photoinitiating activity of ketonic diphenyliodonium photoinitiators. The yield and performance of the novel hybrid photoinitiators are much better than those of the He-type initiator.