Polymers from renewable 1,4:3,6-dianhydrohexitols (isosorbide, isomannide and isoidide): A review

In the last few years, polymers with highly conjugated chains have attracted much attention because of their wide variety of applications in the field of electronics, opto‐electronics, and photonics. Polyimines (PIs) (polymeric Schiff bases) is a class of polymer family, which has been less reviewed. In this paper, we focus on the synthesis methods of PIs by polycondensation, using diamines or hydrazine and dialdehydes, diketones or quinone compounds, or by chemical and electrochemical polymerization of imine oligomers containing terminal oxidable groups (pyrrole, thiophene, furan, naphthalene, etc). PIs with liquid crystalline behavior or having rotaxane and dendrimer architectures are also discussed. Structure, thermal, opto‐electronic, electrical, and mechanical properties and some potential applications of this class of polymers are presented in the last chapters.

Imine Oligomers and Polymers

Poly(isosorbide carbonate) (PIC) was synthesized by melt polycondensation of dimethyl carbonate (DMC) and isosorbide using lithium acetylacetonate (LiAcac) as the catalyst. The reaction conditions were optimized to achieve PIC with relatively high number-average molecular weight (Mn) of 28,800 g/mol and isosorbide conversion of 95.2%. A series of poly(aliphatic diol-co-isosorbide carbonate)s (PAICs) were also synthesized by melt polycondensation of DMC with isosorbide and equimolar amounts of aliphatic diols (1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,4-cyclohexane dimethanol) in the presence of LiAcac and the TiO2/SiO2-based catalyst (TSP-44). PAICs with Mn values ranging from 18,700 to 34,400 g/mol and polydispersities between 1.64 and 1.69 were obtained. The 13C NMR analysis revealed the random microstructure of PAICs. The differential scanning calorimetry results demonstrated that all the PAICs were amorphous with a unique Tg ranging from 46 to 88 °C. The dynamic analysis results showed that the incorporation of linear or cyclohexane structure changed the dynamic mechanical properties of PIC drastically. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013

A non‐phosgene process to homopolycarbonate and copolycarbonates of isosorbide using dimethyl carbonate: Synthesis, characterization, and properties

The synthesis and characterization of new thermoplastic poly(carbonate-urethane) elastomers derived from HDI and aliphatic–aromatic chain extenders

Shape-memory polymers (SMPs) have been rapidly developed in recent decades because they can be fixed in deformed shapes and their original shapes can be recovered by applying an external stimulus. There is an urgent need for SMPs that can deform spontaneously upon an external stimulus. Light acts as a remote and clean stimulus for inducing changes in shape, but light-based deformations cannot be fixed under ambient conditions. Here, we report a novel stimulus-responsive SMP that is capable of shape deformation under UV light and shape fixation in visible light. Finally, the original shape is recovered at higher temperature. This work expands the current understanding of the inherent staging-responsive features in both light- and thermal-induced SMPs, illuminating a new mechanism of staging-responsive shape-memory effects.

New stimulus-responsive shape-memory polyurethanes capable of UV light-triggered deformation, hydrogen bond-mediated fixation, and thermal-induced recovery

Three series of thermotropic liquid crystalline polycarbonates and poly(ester-carbonate)s were prepared by solution polycondensation of 4,4′-biphenyldiol (BP), 4′-hydroxybiphenyl-4-hydroxybenzoate (HHB), or 4-hydroxyphenyl-4″-hydroxybiphenyl-4′-carboxylate (HHBP), as mesogenic unit, with 1,10-bis(p-hydroxybiphenoxy)decane (N10), bisphenol A (BPA), 4,4′-dihydroxy-diphenyl ether (BPO), 4,4′-[phenylbis(oxy)]bisphenol (BPOO), methylhydroquinone (MeHQ), or phenylhydroquinone (PhHQ). One series of cholesteric poly(ester-carbonate)s were also prepared by using HHBP, the aromatic diols mentioned above and isosorbide as the chiral moiety. All polycondensations were implemented in pyridine by using triphosgene as the condensation agent. The synthesized polycarbonates were characterized by viscometer, FTIR, DSC, TGA measurements, polarizing microscopy equipped with a heating stage, and WAXD powder pattern. In this study, it was found that the liquid crystalline properties of polycarbonates strongly rely on the mesogenic unit applied. HHBP-series exhibits a wide temperature region of liquid crystalline (LC) phase even with 50% of bisphenol A (BPA), which is a V-shaped structure and usually destroys liquid crystalline properties. In addition, homopolycarbonate with HHBP structure possesses extraordinarily low phase-transition temperature and wide liquid crystalline phase range, due to its asymmetric structure. This asymmetric structure results in head-to-tail, head-to-head, and tail-to-tail random conformation of polymer chain. The isosorbide containing poly(ester-carbonate)s formed cholesteric phase, which showed homogeneous blue, green, or red Grandjean texture upon shearing in molten state and the Grandjean texture could be frozen easily while quenching the sample to the room temperature. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1852–1860, 2000

Studies on the synthesis and properties of thermotropic liquid crystalline polycarbonates. VII. Liquid crystalline polycarbonates and poly(ester‐carbonate)s derived from various mesogenic groups

Four series of thermotropic polyurethane elastomers (TPUEs) were synthesized in this study. The hard segments were formed by using 4,4′-methylenedicyclohexyl diisocyanate (H12MDI) reacted with various mesogenic units, such as benzene-1,4-di(4-iminophenoxy-n-hexanol), benzene-1,4-di(4-iminophenol), and 3,3′-(4,4′-biphenylene)dipropanol, which also acted as the chain extender. Poly(oxytetramethylene)glycols (PTMEGs), PTMEG-2000 (Mn 2,000) and PTMEG-1000 (Mn 1,000) were used as a soft segment. The structures of all synthesized thermotropic liquid crystalline polyurethanes (TLCPUs) were characterized by FTIR spectroscopy. The effects of mesogenic units on the LC properties and elastic behaviors of LCPUs were studied. It was difficult to show LC behaviors for the PU elastomers derived from the mesogenic units with a lower aspect ratio, such as 3,3′-(4,4′-biphenylene)dipropanol, or the long soft segments, PTMEG-2000. In addition, these PU elastomers show better elastic properties by using a higher aspect ratio mesogenic unit as the chain extender, such as benzene-1,4-di(4-iminophenoxy-n-hexanol and benzene-1,4-di(4-imino-phenol)). The thermal properties were investigated by DSC measurements, thermal optical polarized microscopy, wide angle X-ray diffraction, dynamic mechanical analysis, and thermogravimetric analysis. The mechanical properties were measured by a tensilemeter. © 1996 John Wiley & Sons, Inc.

Studies on thermotropic liquid crystalline polyurethanes. III. Synthesis and properties of polyurethane elastomers by using various mesogenic units as chain extender

Three series of novel thermotropic liquid crystalline polyurethane elastomers (TLCPUEs) were studied. Hard segments were formed by using hexamethylene diisocyanate (HDI) reacted with a mesogenic unit, benzene-1,4-di(4-iminophenoxy-n-hexanol), which also acted as a chain extender. Three diols: 1,10-decanediol,poly(oxytetramethylene) glycol (PTMEG) Mn = 1000 and PTMEG Mn = 2000 were used as the soft segments. The effects of soft segments of polyurethanes on the liquid crystalline behavior were studied. Higher molecular weight TLCPUEs were obtained by adding 30−50 mol % of mesogenic segments to diisocyanates. In contrast to a conventional chain extender such as 1,2-ethylene glycol or 1,4-butyl glycol, the synthesized polyurethane elastomers exhibited a mesophase transition by using a mesogenic unit as the chain extender. Mesophase was found for all synthesized LC polyurethanes except of polymers H2-A-12 and H2-A-7. The structures and the thermal properties of all synthesized TLCPUEs were studied by using FTIR spectroscopy, wide-angle x-ray diffraction (WAXD) and DSC measurements, a polarizing microscope equipped with a heating stage, dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA). Mechanical properties were also examined by using a tensilemeter. © 1995 John Wiley & Sons, Inc.

Studies on thermotropic liquid crystalline polyurethanes. II. Synthesis and properties of liquid crystalline polyurethane elastomers

Three series of novel thermotropic liquid crystalline polyester elastomers (TLCPEEs) were prepared by direct polycondensation from terephthalic acid, polyols (M n = 1000 or 2000), and various diols. The structures and thermal properties of the synthesized TLCPEEs were examined by FTIR spectroscopy, differential scanning calorimetry, thermal optical polarized microscopy, thermogravimetric analysis, and wide-angle x-ray diffraction. The effects of kinds and amount of diols and the molecular weight of polyols on the thermal properties of TLCPEEs were studied. By introducing long flexible spacers (PE-1000 or PE-2000) into the polymer main chain, all polymers showed two-phase morphology under the thermal optical microscopic observation. All of the synthesized polymers, except polymer P1-BPA60 and P2-BPA60, which were prepared from BPA, exhibited thermotropic liquid crystalline properties that were in the smectic phase.

Studies on thermotropic liquid crystalline elastomers. II. Synthesis and properties of liquid crystalline polyester elastomers

Several series of fully aromatic liquid crystalline polycarbonates were synthesized by interfacial or solution polycondensation from triphosgene with aromatic diols, such as hydroquinone, 4,4′-biphenyldiol, 2,6-naphthalenediol, Bisphenol A, 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxydiphenylsulfide, 4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenyl ether, methylhydroquinone, t-butylhydroquinone, phenylhydroquinone, and resorcinol, respectively. The structures and thermal properties of the synthesized polycarbonates were examined by FT IR spectroscopy, differential scanning calorimetry (DSC), thermal optical polarized microscopy, and thermogravimetric analysis (TGA). The effects of the structures of polycarbonates on liquid crystalline properties and thermal stability were investigated. The thermotropic LC properties of polycarbonates are strongly dependent on the structures and content of the bent units. The non-linearity of carbonate linkage can be compensated for by bent units in some case.

/pdf/thermotropic-liquid-crystalline-polycarbonates-vi-synthesis-3dvxiuvg0v.pdf

Thermotropic Liquid Crystalline Polycarbonates VI. Synthesis and Properties of Fully Aromatic Liquid Crystalline Polycarbonates by Interfacial or Solution Polycondensation

Shih-Jieh Sun

Papers

Studies on the synthesis and properties of thermotropic liquid crystalline polycarbonates. VII. Liquid crystalline polycarbonates and poly(ester‐carbonate)s derived from various mesogenic groups

Studies on thermotropic liquid crystalline polyurethanes. III. Synthesis and properties of polyurethane elastomers by using various mesogenic units as chain extender

Studies on thermotropic liquid crystalline polyurethanes. II. Synthesis and properties of liquid crystalline polyurethane elastomers

Studies on thermotropic liquid crystalline elastomers. II. Synthesis and properties of liquid crystalline polyester elastomers

Thermotropic Liquid Crystalline Polycarbonates VI. Synthesis and Properties of Fully Aromatic Liquid Crystalline Polycarbonates by Interfacial or Solution Polycondensation