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A highly robust and flame retardant borate-crosslinked poly (vinyl alcohol)/montmorillonite aerogel is fabricated through a novel melt-crosslink method. In this way, the PVA/MMT hydrogel was prepared by immersing the frozen PVA/MMT sol into a borax solution, inducing crosslinking between diols of PVA and borate exactly during the ice melt. As a result, rearrangement of the polymer chains and subsequent...
In this work, we present a mild one-step enzymatic-catalyzed copolymerization of diethyl succinate, 1,4-butanediol and p-dioxanone (PDO) to synthesize poly(p-dioxanone-co-butylene-co-succinate) copolyesters. Their chemical structure, triad distributions, and molecular weight of the copolyesters are characterized by 1H NMR, 13C NMR and GPC. All copolyesters have narrow molecular weight polydispersity...
Miktoarm star copolymers, which are in the simplest form of branching, are particularly of interest to biomedical applications. Nevertheless, their synthesis is facing troubles of seeking inner cores with heterogeneous functional groups as well as tedious protection and deprotection. Herein, ethyl-β-d-glucopyranoside, a sugar molecule containing homogeneous groups, was directly employed as a core...
In order to avoid the serious melt-dripping problems caused by conventional phosphorus flame retardants, a new arylene-ether containing monomer named 2,2′-(4,4′-(1,4-phenylenebis(oxy))bis(4,1-phenylene))bis(oxy) diethanol (PBPBD) was synthesized and introduced into the PET main-chain via condensation polymerization. With the incorporation of arylene-ether units, the thermal stability and the char...
A self-cross-linkable poly(ethylene terephthalate) block copolyester (SSP-PETPx) has been synthesized via solid-state polymerization (SSP). In the SSP process, a cross-linkable monomer named 4-(phenylethynyl) di(ethylene glycol) phthalate (PEPE) is incorporated into the amorphous phase of PET. The sequence distribution of the resulted copolyester SSP-PETPx is analyzed with 1H NMR, showing that the...
Dihydroxyl terminated poly(butylene succinate) ionomer precursors (Pre-PBSIs) with different ionic group contents were prepared to chain-extend with dihydroxyl terminated poly(butylene succinate) to synthesize high molecular weight poly(butylene succinate) ionomers (PBSIs) with controlled ionic group distributions. The chemical structures and molecular weights of the precursors and PBSIs were characterized...
In order to realize a more effective and environmentally friendly flame-retardant treatment for melamine foam, which is expected to be used as highly flame-retardant cellular polymeric materials for building and construction, a novel intumescent flame-retardant nanocoating, comprised of positively charged chitosan (CH) and negatively charged ammonium polyphosphate (APP), is deposited on high open-cell...
A series of copolyesters containing ionic groups (PETIs-K) were synthesized by melt co-polycondensation using terephthalic acid, ethylene glycol, and potassium salt of bishydroxyethyl ester of 10-hydroxy-10-oxo-10H-phenoxaphosphine-2,8-dicarboxylic acid (DHPPO-K) as monomers. The copolyesters only with analogous phosphorus-containing heterocycles (PETPs) were also synthesized and used as a control...
The segmented poly(butylene succinate) urethane ionenes (PBSUI) containing secondary amine cation were synthesized by chain extension reaction of dihydroxyl terminated poly(butylene succinate) and diethanolamine hydrochloride (DEAH) in the presence of hexamethylene diisocyanate. NMR, DSC, WAXD, POM, SAXS, DMA, and rotational rheometer were used to characterize the structure and properties of the PBSUI,...
Flame-retardant-free and thermo-cross-linkable copolyesters have been synthesized, and their flame retardation and anti-dripping behavior as a consequence of cross-linking during combustion were investigated in detail. TG-DSC simultaneous thermal analysis, rheological analysis, and TGA established the extent and rate of the cross-linking reaction. The extent of cross-linking depends on the content...
A facile preparation of poly(vinyl alcohol) (PVOH) hydrogels and their derivative PVOH/montmorillonite clay aerogels is reported, using water as solvent and divinylsulfone as crosslinking agent, making use of an environmentally friendly freeze drying process. The materials exhibit significantly increased mechanical properties after crosslinking. The compressive modulus of an aerogel prepared from...
Low flammability, foam-like materials based on bio-based, renewable ammonium alginate and sodium montmorillonite clay were fabricated through a simple, environmentally-friendly freeze-drying process in which water is used as solvent. These materials exhibit mechanical properties similar to those of rigid PU foams or balsa; the compressive modulus (1–97 MPa) and density (0.047–0.174 g/cm 3 ...
The crystallization kinetics, morphology and crystal structure of biodegradable double crystalline poly(butylene succinate)-poly(ethylene glycol) (PBS-PEG) multiblock copolymers (PBSEGs) were studied with different composition and segment chain length by differential scanning calorimetry (DSC), polarized optical microscopy (POM) and wide-angle X-ray diffraction (WAXD). The isothermal crystallization...
Phosphorus-containing flame-retardant monomer entitled 9,10-dihydro-10-[2,3-di(hydroxycarbonyl)propyl]-10-phospha-phenanthrene-10-oxide (DDP) was first esterified with 1,3-propane diol, then incorporated in poly(trimethylene terephthalate) (PTT) chain via solid-state polymerization (SSP) at 200 °C. Reaction kinetics of incorporation was studied choosing 30 wt% DDP content as representative example...
Poly(ethylene glycol) (PEG) segments were incorporated into poly(ethylene succinate) (PES) by chain-extension reaction of PEG with PES using 1,6-hexamethylene diisocyanate as a chain-extender, forming a poly(ester ether urethane) (PEEU). The chemical structures and molecular weights of the PEEUs were determined by 1 H NMR and GPC, respectively. The composition dependence of thermal transitions,...
Polycarbonate (PC) was blended with various loadings of novel phosphorus-containing thermotropic liquid crystalline copolyester named PHDDT to form the in situ reinforced composites (PC/PHDDT) by flake extrusion. The morphology, thermal behaviors, tensile properties and flame-retardant performances of PC/PHDDT composites were investigated. Results suggested that fine deformation and microfibrillation...
An inherently flame-retardant poly(lactic acid) (PLA) was synthesized via the chain-extending reactions of dihydroxyl terminated pre-poly(lactic acid) (pre-PLA), which was synthesized by direct polycondensation of l-lactic acid using 1,4-butanediol as initiator and stannous chloride (SnCl 2 ) as catalyst, using ethyl phosphorodichloridate as chain extender. The resulting phosphorus-containing...
For polymer/liquid crystal polymer (LCP) blend systems, the in-situ fibrillation of LCP in polymer matrix can result in the self-reinforcement of polymer/LCP composites. How to control the microfibrillation of LCP in matrix is a key to enhance the mechanical properties of composites. In this paper, we investigated the transesterification-controlled compatibility and microfibrillation of phosphorus-containing...
A novel biodegradable multiblock poly(ester urethane) (PEU), consisting of poly(l-lactic acid) (PLLA) and poly(butylene succinate) (PBS) blocks, has been successfully synthesized via chain-extension reaction of dihydroxyl terminated PLLA (PLLA-OH) and PBS prepolymers (PBS-OH) using toluene-2,4-diisocyanate (TDI) as a chain extender. The chemical structures and molecular weights of PEUs, containing...
A novel biodegradable copolymer was synthesized from poly(vinyl alcohol) and poly(p-dioxanone) by ring-opening polymerization. The molecular structure of the copolymer was characterized by one- and two-dimensional NMR spectroscopy. The results of differential scanning calorimetry (DSC) show that the amphiphilic and comb grafted structure of the copolymer make its crystalline behavior different from...
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