s-Triazine containing flame retardant hyperbranched polyamines: Synthesis, characterization and properties evaluation

A s-triazine containing hyperbranched polyamine (HBPA) has been synthesized from cyanuric chloride and aromatic diamine, 4,4′-(1,4-phenylenediisopropylidene) bis-aniline by nucleophilic displacement polymerization technique using an A₂ + B₃ approach with high yield (>80%). The synthesized polymer has been characterized by ¹H NMR, ¹³C NMR, FT-IR spectroscopic studies, elemental analysis, solubility and measurement of solution viscosity. The thermogravimetric (TG) analysis and differential scanning calorimetric (DSC) studies indicate that the polymer is thermostable upto 290 °C without any decomposition and has glass transition temperature of 243 °C. The flame retardancy of the pure powder polymer and the blends with linear commercial polymers such as plasticized PVC and LDPE with this hyperbranched polymer were investigated by the measurement of limiting oxygen index (LOI) value. The results show that the polymer has self-extinguishing characteristic (LOI = 38) and acts as an effective flame retardant additive for the above linear base polymers. The synergistic effect of this hyperbranched flame retardant was observed with triphenyl phosphine oxide in the same base polymers. The flammability efficiency of the hyperbranched polyamine is also evaluated by help of thermogravimetric (TG) analysis. The heat aging and leaching in different chemical media did not influence the flame retardancy of the blends.     

Synthesis of multi-arm star polystyrene with hyperbranched polyether core

Multi-arm star polystyrenes with hyperbranched poly(3-ethyl-3-oxetanemethanol) (PEOM, 3) core were synthesized by atom transfer radical polymerization (ATRP) method. The structures of polymers were confirmed by FT-IR and ¹H NMR. GPC results showed that the resultant polymers had relatively low polydispersity indices (PD = 1.47-2.03). DSC analysis indicated that polystyrene star polymers had a glass transition temperature (T_g = 42.2-91.5 °C) that changed with the amount of the polystyrene in the polymers. In addition, the aggregation behavior of the multi-arm star polystyrenes in a selective solvent (THF/cyclohexane) was probed with polystyrene arms that encapsulated in the aggregates and PEOM cores hidden in the center of the micelles.     

Synthesis and thermal decomposition of a novel hyperbranched polyphosphate ester used for flame retardant systems

A novel hyperbranched polyphosphate ester (HPPE) was synthesized via the polycondensation of bisphenol-A as an A₂ monomer and phosphoryl trichloride as a B₃ monomer at 100 °C, without gelation. The initial molar ratio of A₂ to B₃ was set to be 1.5:1. The final product was precipitated from methanol. ³¹P NMR spectroscopy was used to monitor the reaction. The formed HPPE was characterized by FTIR and ¹H NMR to confirm its end groups. Differential scanning calorimetry data revealed that the cured bisphenol-A epoxy resin with HPPE as a curing agent possessed improved glass transition temperature. Dynamic mechanical thermal analysis also showed the increase in the glass transition temperature. The thermal degradation properties and flame retardancy were investigated by thermogravimetric analysis and limiting oxygen index (LOI). The results showed that the incorporation of HPPE into bisphenol-A epoxy resin increased its thermal stability and char yield during the decomposition by raising the second stage decomposition temperature. The LOI value increased from 23 to 31 when HPPE, instead of bisphenol-A, was used as a curing agent.     

一种低代超支化聚醚的合成、表征及表面活性研究

以十二胺、丙烯酸甲酯和乙二胺为原料,甲醇为溶剂,采用发散合成法合成一种低代超支化分子骨架.采用1H NMR对分子骨架的结构进行了表征.在此基础上,以低代骨架为起始剂,分别与环氧乙烷、环氧丙烷加成制备了一种超支化聚醚,测定了它的表面张力、浊点,同时计算出了它的HLB值.结果表明:骨架的分子结构与所设计的结构相符,合成的聚醚具有典型表面活性剂的性质.     

Physical, thermal, dielectric and chemical properties of a hyperbranched polyether and its linear analog

The hyperbranched and the linear polyethers were prepared by one-pot nucleophilic displacement polymerization technique using cyanuric chloride and aromatic diol as reported earlier. The physical, thermal, dielectric and chemical properties of the hyperbranched polyether and its linear analog have been studied. The amorphous character of both the polyethers was observed in XRD study. The solubility studies showed that the hyperbranched polyether has relatively higher solubility in different solvents compared to its linear analog. The thermal properties of both polymers have been studied by thermogravimetric (TG) and differential scanning calorimetric (DSC) analyses. The chemical resistance tests indicated that both polyethers are very good chemical resistances except in dilute aqueous alkali solution. The dielectric properties such as dielectric constant and loss factor for both polyethers have also been studied with respect to changes of frequency (50-500 kHz) and temperature (303-343 K).     

Synthesis and properties of a novel hyperbranched polyphosphate acrylate applied to UV curable flame retardant coatings

A series of hyperbranched polyphosphate acrylates (HPPAs) being used for UV curable flame retardant coatings were prepared by the reaction of tri(acryloyloxyethyl) phosphate (TAEP) with piperazine at given ratios, and characterized using FTIR, ¹H NMR and GPC measurements. HPPA was blended with TAEP in different ratios to obtain a series of UV curable resins. Their maximum photopolymerization rates and final unsaturation conversion (P^f) in the cured films at the presence of a photofragmenting initiator were investigated. The results showed that the P^f increased along with HPPA content and the pure HPPA has the maximum value of 82.1% in the photo-DSC analysis. The data from dynamic mechanical thermal analysis showed that HPPA has good miscibility with TAEP. The crosslinking density and T_g of the cured film decrease along with the content of HPPA in the blend. The mechanical properties of the cured films were also investigated. Less than 20% HPPA addition improved both the tensile strength and elongation at break without damaging the modulus. The HPPA₂₀TAEP₈₀ film with 20% HPPA addition has the highest tensile strength of 31.7 MPa and an elongation at break two times that of cured TAEP. The flame retardancy of the UV cured films was investigated by the limiting oxygen index (LOI). The cured TAEP/HPPA samples greatly expanded when burning, and the degree of expansion increased along with HPPA content. However, the LOI values decreased from 47.0 to 34.0 along with HPPA content, which can be ascribed to that the flame retardancy of TAEP is mainly acting in the gas phase, whereas HPPA mainly acting in condensed phase, and the gas phase mechanism holds the dominant effect while their blends are burning.     

Synthesis and characterization of hyperbranched polyurethane-benzyltetrazole

A series of hyperbranched polyurethane-benzyltetrazoles（H-PBTZs） with different linkage structures were synthesized via the polycondensation of hexamethylenediisocyanate as an A₂ type monomer with（4-（1H-tetrazol-5- yl）benzyl）-diethanolamine（TBDEA） as a BB’₂ type monomer in the absence of catalyst at different temperatures.The FTIR, and ¹³C and ¹H-NMR spectroscopy were used to characterize the molecular structures of TBDEA and H-PBTZs as well as the counterpart linear polyurethane-benzyltetrazole（L-PBTZ）.The molecular composition was determined by the reaction selectivity that the isocyanate group reacted with the hydroxyl group in diethanolamine segment or the active hydrogen atom on tetrazole ring.Raising reaction temperature was propitious to the reaction of isocyanate group with the active hydrogen atom on tetrazole ring.The degrees of branching（DB） for H-PBTZs obtained from the ¹H-NMR spectra increased with raising reaction temperature.The wider molecular weight distribution of 1.7-2.9 for H-PBTZs was obtained via GPC analysis.TGA results showed that H-PBTZs had high thermal stability compared with L-PBTZ.     

Synthesis and characterization of hyperbranched polyurethane-urea coatings

A series of hyperbranched polyurethane (HBPU)-urea coatings were synthesized by a systematic two-step reaction process. Initially, isocyanate terminated PU prepolymers were prepared from a hyperbranched polyester polyols with isophorone diisocyanate at NCO/OH ratio of 1.6:1 for 5 h at 70-80 °C. The excess NCO content after the synthesis of NCO terminated HBPU prepolymer was completely reacted with atmospheric moisture. The obtained HBPU-urea networks were characterized with Fourier transform-infrared (FT-IR) spectroscopy for the quantitative evolution of the extent of urethane and urea bonds as well as to study the structure-property relationship. In order to find out the changes and types of intermolecular H-bonding interaction in the HBPU-urea films with the variation in polyester structure, the deconvolution of FT-IR spectra were carried out using Origin 6.0 software through Gaussian curve-fitting method. The viscoelastic properties and thermal stability of the synthesized coatings were determined by dynamic mechanical and thermal analyzer and thermogravimetric analyzer, respectively. For HBPU-urea samples glass transition temperature and thermal stability increased with the generation number from the first to the third. Polyester samples showed single step decomposition profile and HBPU-urea samples showed two-steps decomposition with good thermal stability.     

Synergistic effect between a novel hyperbranched charring agent and ammonium polyphosphate on the flame retardant and anti-dripping properties of polylactide

A novel hyperbranched polyamine charring agent (HPCA), a derivative of triazines, was synthesized and well characterized by ¹H NMR and FTIR. HPCA and ammonium polyphosphate (APP) were added into polylactide (PLA) resin as an intumescent flame retardant (IFR) system to impart flame retardancy and dripping resistance to PLA. The flammability and thermal stability of IFR-PLA composites were investigated by limiting oxygen index (LOI), UL-94 vertical burning, cone calorimetry and thermogravometric analysis (TGA) tests. The results showed that the IFR system had both excellent flame retardant and anti-dripping abilities for PLA. The TGA curves suggested that HPCA has good ability of char formation and when combined with APP, would induce synergistic effect which could be clearly observed. This effect greatly promoted the char formation of IFR-PLA composites, hence improved the flame retardant property. Additionally, the structure and morphology of char residues were studied by XPS, FTIR and SEM.     

Thermal degradation behavior of hyperbranched polyphosphate acrylate/tri(acryloyloxyethyl) phosphate as an intumescent flame retardant system

The hyperbranched polyphosphate acrylate (HPPA) was blended in different ratios with tri(acryloyloxyethyl) phosphate (TAEP) to obtain a series of UV curable intumescent flame retardant resins. The thermal degradation mechanism of their cured films in air was studied by thermogravimetric analysis and in situ Fourier-transform infrared spectroscopy. The results showed that the addition of HPPA reduced the initial decomposition temperature (T_di) but increased the char residue. Moreover, the decomposition was considered to be divided into three stages: firstly the degradation of phosphate group, secondly ester group and finally alkyl chain. The morphological structure of the formed char was observed by scanning electron microscopy, demonstrating the formation mechanism of the intumescent charred crust.     

Synthesis of aromatic hyperbranched PAMAM polymers

Our preliminary results towards the synthesis of hyperbranched polyamidoamine (PAMAM) polymers as ‘dendrimer equivalents’ is described. An aromatic AB₂ bis-amino acid monomer was polymerised at 165 °C (under vacuum) and the crude mixture purified by dialysis. Analysis by GPC and MALDI-TOF mass spectroscopy showed that the purified hyperbranched polymers possessed an M_n of 2000 and a PD of 3.2.     

Synthesis and characterization of polyurethanes from epoxidized methyl oleate based polyether polyols as renewable resources

Oligomeric polyether polyols were obtained through the acid‐catalyzed ring‐opening polymerization of epoxidized methyl oleate and the subsequent partial reduction of ester groups to give primary alcohols. The oligomers were characterized with titration, spectroscopic techniques (Fourier transform infrared and nuclear magnetic resonance), matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, size exclusion chromatography, and differential scanning calorimetry. Depending on the degree of reduction, polyols of different hydroxyl content values were obtained and were reacted with 4,4′‐methylenebis(phenyl isocyanate) to yield polyurethanes. These materials, which were characterized by differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical thermal analysis, could behave as hard rubbers or rigid plastics. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 634–645, 2006     

A tumor pH-responsive complex: carboxyl-modified hyperbranched polyether and cis-dichlorodiammineplatinum(II)

To realize the pH-targeting delivery of antitumor drug cis-dichlorodiammineplatinum(II) (cisplatin, CDDP), a tumor pH-responsive polymer-platinum(II) complex (Suc-HPMHO-CDDP) from carboxyl-modified hyperbranched polyether (Suc-HPMHO) and cisplatin was designed and prepared. Because of the existence of hydrophobic core and ionization of surface carboxylic acid, Suc-HPMHO showed reversible pH-response in aqueous solution, and its responding pH value could be readily adjusted by only changing the degree of carboxylation of Suc-HPMHO. With plenty of terminal carboxyl groups, Suc-HPMHO could form the complex with CDDP by substituting the chloride ions with carboxyls. Methyl tetrazolium (MTT) assay showed that Suc-HPMHO had low cytotoxicity, while Suc-HPMHO-CDDP complex presented a similar antitumor effect with the free CDDP. Under the tumor acidic pH (pH(e)), Suc-HPMHO-CDDP complex deposited around/in cells because of its pH-response. Therefore, the pH-targeting of Suc-HPMHO-CDDP complex to tumor tissue could be realized. All of these results show that the tumor pH-responsive Suc-HPMHO-CDDP complex is a potential pH-targeting drug delivery system in cancer therapy.     

Synthesis and structural characterization of a yttrium coordination polymer formed by bridging of an acyclic polyether

The amide-type acyclic polyether, 1,2-ethylenedioxy-bis(N-pyridin-2-ylmethyl-benzamide) (L) was synthesized and characterized by EA, IR and ¹H NMR spectroscopy. The reaction of yttrium nitrate with L produced a rare chain structural coordination polymer {[Y(NO₃)₃L(H₂O)]?·?(H₂O)} _n (1) by use of the flexible ligand L as the building blocks. The structure of 1 was determined by X-ray crystallography and thermal analysis. In 1, L, as a bidentate bridging spacer, binds two neighboring Y atoms to form a one-dimensional chain polymer. The chain polymer was further connected into the three-dimensional network by hydrogen bonding interactions.     

Synthetic hydromagnesite as flame retardant. Evaluation of the flame behaviour in a polyethylene matrix

Synthetic hydromagnesite obtained from an industrial by-product was evaluated as a non-halogenated flame retardant. It was used in combination with aluminium hydroxide (ATH) and compared with commercial flame retardants like magnesium hydroxide (MH) and natural hydromagnesite-huntite (U) in a polyolefin system of low-density polyethylene/poly(ethylene-co-vinyl acetate) (LDPE/EVA).The thermal stability and flame behaviour of the halogen free flame retarded composites were studied by thermogravimetric and differential thermal analysis (TG-DTA), limiting oxygen index (LOI), epiradiateur and cone calorimeter. It has been shown that synthetic hydromagnesite could be an alternative solution to the use of MH in non-halogenated flame retardant systems in EVA.     

Synthesis and characterization of a new fluorinated polyether glycol prepared by radical grafting of hexafluoropropylene onto polytetramethylene glycol

A new fluorinated polyether glycol (PTMG-g-HFP) was prepared by radical grafting of hexafluoropropylene (HFP) onto polytetramethylene glycol (PTMG) in the presence of different initiators. The structure of PTMG-g-HFP was characterized by means of IR, ¹H NMR and ¹³C NMR. The effects of nature and amount of initiator, reaction time and reaction temperature on grafting HFP onto PTMG were investigated. The results showed di-tert-butyl peroxide (DTBP) was the most efficient in the reaction and the optimal reaction conditions were: [DTBP]₀/[PTMG]₀, 0.12; reaction temperature, 140 °C; reaction time, 6 h.     

氨基改性聚醚硅油的合成、结构表征及应用

在Pt催化剂的作用下，利用含氢硅油与烯丙基缩水甘油醚、烯丙基聚氧乙烯聚氧丙烯醚的硅氢化加成反应合成聚醚／环氧硅油中间体，然后分别用吗啉、乙二胺、N,N-二甲基丙二胺、N-氨乙基哌嗪等氨解开环，制得了一系列氨烃基改性聚醚硅油AMPES，对其进行了结构表征和应用。结果表明：增加含氢硅油的数均分子量，提高硅含量，可改善AMPES的柔软性，而对织物的吸湿性影响不大。     

磷系阻燃剂杂环己内磷酸酯衍生物的合成及性能研究

近年来,高分子材料被引燃而导致的火灾事故日益频繁,特别是公共场所的特、重大火灾时有发生,给人民生命财产造成巨大损失。因此,对高分子材料进行阻燃处理,赋予其难燃性和抑烟性,有助于提高其防火安全性和减少火灾损失。在过去相当长时间里,卤系阻燃剂在高分子材料阻燃中发挥着     

Synthesis and applications of hyperbranched polymers

The development of hyperbranched polymers is a rapidly expanding field in the area of macromolecular science. This short review highlights some of the notable examples in the synthesis of hyperbranched polymers and some of the key advances that have been made in the application of these hyperbranched materials in the areas of material property modifications and in high value technologies.     

Synthesis and characterization of a novel organophosphorus flame retardant and its application in polypropylene

A novel organophosphorus containing spiro and caged bicyclic phosphate, 3,9‐Bis‐(1‐oxo‐2,6,7‐trioxa‐1‐phospha‐bicyclo[2.2.2]oct‐4‐ylmethoxy)‐2,4,8,10‐tetraoxa‐3,9‐diphospha‐spiro[5.5]undecane 3, 9‐dioxide (SBCPO), was synthesized and characterized by Fourier transform infrared (FTIR), hydrogen‐1 nuclear magnetic resonance (NMR) and phosphorus‐31 NMR. The flame retardancy of polypropylene (PP) containing the novel intumescent flame retardant (IFR) based on the combination between SBCPO and melamine (MA) was studied by limiting oxygen index (LOI), UL‐94 test and cone calorimeter test. Results indicated that this combination showed the excellent flame retardancy for PP at appropriate proportions (with the total loading of 30 wt. % and SBCPO: MA = 4:1). The value of LOI was as high as 31.6, and the rating in UL94 reached to V‐0. Moreover, the HRR and THR of IFR/PP decreased significantly in comparison with that of neat PP. The scanning electron microscopy results indicated that the incorporation of SBCPO could induce the formation of intumescent char layer, which retarded the degradation and combustion process of PP. The thermal oxidative degradation of the PP samples at different temperature was analyzed by FTIR. The thermal stabilities of the composites were further investigated by thermogravimetric analysis. It was found that the amount of residues was increased greatly with the addition of SBCPO that remained in the form of polyaromatic stacks and phosphoric or polyphosphoric acid at the residual chars. Copyright © 2013 John Wiley & Sons, Ltd.