一种可功能化的Boltorn型超支化聚酯的合成研究

采用一步法,以季戊四醇(B4单体)为核,2,2-二羟甲基丙酸(AB2单体)为单体,钛酸正丁酯为催化剂,合成了Boltorn型超支化(Hyp-DMPA)。采用FT-IR、NMR和化学滴定等方法对产物进行了表征和分析,并研究了超支化聚酯的缩聚反应动力学。以IR、1H-NMR证实了聚酯结构的存在,13C-NMR谱图上3种季碳的特征峰有力证实了超支化分子结构的存在,MALDI-TOF MS证明了超支化聚酯的成功合成,并计算超支化聚酯的支化度为0.408;探讨并建立了超支化聚酯的缩聚反应动力学方程-d[—COOH]/dt=K[—COOH][—OH],该缩聚反应属于二级反应,反应速率由羧基浓度和羟基浓度共同决定。     

超支化聚酯的端基改性及其涂膜性能

以三羟甲基丙烷为核多元醇,二羟甲基丙酸为AB₂型单体,对甲苯磺酸为催化剂准一步法合成了第二代超支化聚酯(HBP-0)。HBP-0分别经己内酯和月桂酸改性得到改性超支化聚酯(HBPs)。采用FT-IR、¹H NMR和GPC对HBP-0的结构和相对分子质量进行表征,发现超支化聚酯的支化度为0.43,相对分子量与理论相对分子量比较接近, 相对分子质量分布系数只有1.72。以甲苯二异氰酸酯加成物为交联剂,考察了改性超支化聚酯交联涂膜性能,结果表明,3种改性超支化聚酯的涂膜性能在光泽度、耐冲击性、附着力和柔韧性方面表现十分优异。其中HBP-3同时用己内酯和月桂酸改性具有最佳性能,黏度最低为7500 mPa·s,涂膜表干40 min,且硬度达到F。而单独用己内酯或月桂酸改性的HBP-1和HBP-2的相应数据分别为7×10⁵ mPa·s、20 min和HB及17500 mPa·s、90 min和2B。     

二元醇为核单体的超支化聚酯的合成与性能

分别以乙基丁基丙二醇(BEPD)、1,4-丁二醇(BDO)和新戊二醇(NPG)为核单体,二羟甲基丙酸为AB2型单体,对甲苯磺酸为催化剂,采用准一步法合成了第三代超支化聚酯(HBP-1、HBP-2和HBP-3)。采用FT-IR、1H-NMR和GPC对其结构和分子量进行表征并测定了超支化聚酯的特性黏度。以甲苯二异氰酸酯加成物为固化剂,研究了超支化聚酯的固化涂膜性能,使用热重分析仪(TGA)考察了超支化聚酯涂膜的热稳定性能。结果表明,三种核单体成功合成了超支化聚酯,以BEPD为核单体的超支化聚酯HBP-1具有最高的支化度达到0.55。GPC测得的分子量与理论分子量接近,且以BEPD为核的HBP-1分子量分布最低为1.68。超支化聚酯在极性溶剂中有较好的溶解性能,在非极性溶剂中不溶,其中HBP-1具有更好的溶解性能和较低的特性黏度(4.24 mL g 1)。超支化聚酯的固化涂膜具有较好的热稳定性、优异的附着力、柔韧性和较高的硬度。     

棕榈酸对脂肪族超支化聚酯的端基改性研究

采用准一步法,以三羟甲基丙烷为核,2,2-二羟甲基丙酸为AB2型单体合成超支化聚酯。为了拓宽其使用范围,用棕榈酸(十六碳酸)对超支化聚酯进行端基改性,成功地找出了提纯的方法,并进行了表征。测试结果表明,聚酯的端羟基大约有97%被酯化,说明方法可行。与用棕榈酰氯进行改性相比,大大节约了成本。     

以季戊四醇为核的超支化树脂的研究

以季戊四醇(B4)、2,2-二羟甲基丙酸(AB2)和对甲苯磺酸通过准一步熔融缩聚反应合成了常温为玻璃态的不同代数脂肪族超支化聚酯.采用13C NMR、FI-IR、GPC、DSC等方法对其结构和性能等进行了表征与分析.结果表明得到了高转化率、相对分子质量分布较窄、支化度较高且Tg在60～80℃的超支化聚酯.以甲基丙烯酸为反应试剂,对超支化聚酯进行部分端基改性,得到了粉末状改性超支化树脂,可以进一步为合成UV涂料主体树脂提供指导.     

超支化聚芳酰胺合成及表征

由3,5-二硝基苯甲酰氯和间氨基苯甲酸合成了一种超支化AB2型单体3-(3,5-二氨基苯甲酰氨基)苯甲酸,该单体进行自缩聚反应,合成了新型超支化聚酰胺(a),将其与酰氯反应,制得7种封端超支化聚合物(b￣h)。所得聚合物通过红外光谱(FT-IR)、核磁共振(1H-NMR)和差示扫描量热法(DSC)等进行了表征。聚合物a￣h的特性黏度为0.063￣0.077dL/g,玻璃化转变温度(Tg)为54￣188℃。聚合物b￣d的Tg随封端剂脂肪链增长而降低,聚合物e￣h的Tg随封端剂极性增加而升高。封端改性后,聚酰胺的溶解性得到了不同程度的改善。     

一种端羧基超支化聚酯阻垢剂的合成及其阻垢性能研究

针对多晶硅换热器运行过程结垢问题,以三羟甲基丙烷(TMP)为核、2,2-二羟甲基丙酸(DMPA)为AB2型聚合单体,合成端羟基超支化聚酯(HBP-OH),再以马来酸酐(MAH)进行端羟基改性,得到一种端羧基超支化聚酯(HBP-OMA)阻垢剂,考察了反应时间、反应温度、n(HBP-OH):n(MAH)对HBP-OMA阻垢...     

端羧基超支化聚酯阻垢剂的制备及性能研究

以季戊四醇(PE)与2,2-二羟甲基丙酸(DMPA)为原料,采用"一步法"合成二代超支化聚酯(HBPE-OH),通过马来酸酐(MAH)对HBPE-OH进行改性、羧酸化,生成超支化聚酯(HBPE-COONa)。使用红外光谱和核磁共振对超支化聚酯进行结构表征,用静态阻垢法测定阻垢率,探究合成和改性过程中时间、温度、催化剂用量对阻垢率的影响。结果表明,阻垢剂合成最佳温度为145℃,合成时间6 h,催化剂用量为0.5%(质量分数);改性最佳温度105℃,改性时间3 h,催化剂用量0.1 mL。冷却循环水中含有超支化阻垢剂6 mg/L时,对硫酸钙的阻垢率可达97.1%,优于聚环氧琥珀酸钠和聚丙烯酸钠等市售阻垢剂。     

超支化聚酯的合成及改性环氧树脂的研究

以季戊四醇为核,2,2-二羟甲基丙酸为增长单体,对苯甲磺酸为催化剂,合成了超支化聚酯,通过FI-IR图谱对超支化聚酯进行结构表征,证明得到端基为羟基的超支化聚酯。采用超支化聚酯做增韧剂,研究其对环氧/四氢苯酐固化体系的增韧作用,探讨了超支化聚酯的分子量(代数)、超支化聚酯的含量、固化温度等因素对环氧树脂固化体系力学韧性的影响。     

超支化聚(酰胺-酯)的合成与改性

以邻苯二甲酸酐和二乙醇胺为原料,制得AB2型单体;加入三羟甲基丙烷为核,采用一步法合成了超支化聚(酰胺-酯),并用硬脂酸对所得聚合物进行封端改性.应用红外光谱对改性前后超支化聚合物进行了表征.结果表明,所合成的聚合物与理论结构相吻合,且硬脂酸与端羟基发生了酯化反应,成功地接到了聚合物上.     

UV固化超支化聚酯丙烯酸酯的合成及其固化性能

以季戊四醇、2,2-二羟甲基丙酸、丁二酸酐和甲基丙烯酸羟乙酯为原料,合成一种新型UV固化超支化聚酯丙烯酸酯(HPA)。通过红外光谱、核磁共振谱表征了其结构;测试了相对分子质量及其分布和黏度;并考察了其紫外光固化性能。结果表明:在反应时间6 h、反应温度90 ℃、n[HP-(COOH)₈]∶n(HEMA)=1∶8时合成的HPA,当用4.5%的光引发剂1173引发固化时,UV辐照能量最小,为600 J/m ²,且固化速度比市售低聚物RJ544组成的相似体系快5倍,其双键的转化率可达89.8%。在制备的HPA经UV固化后,涂膜的铅笔硬度为2H,附着力为1级,柔韧性为0.5 mm。     

Hyperbranched polyesters with carboxylic acid functional groups for the inhibition of the calcium carbonate scale

Scale deposits exist widely in industrial water‐cooling systems and oil‐production systems, causing severe damage to the equipment. The most effective way to prevent the formation of scale has been to use an inhibitor. The use of a hyperbranched polymer as an inhibitor, however, has rarely been reported. In this study, we prepared a hydroxyl‐terminated hyperbranched polyester (HBPE–OH) with trimethyloypropane as the core and 2,2‐bis(hydroxymethyl)propionic acid as an AB₂ monomer. The HBPE–OH was then modified with succinic anhydride to obtain the carboxyl‐terminated hyperbranched polyester (HBPE–COOH). The effects of the dosage, Ca²⁺ concentration, pH value, and temperature of the system on the inhibition efficiency were investigated when HBPE–COOH was used as an inhibitor of calcium carbonate (CaCO₃) scale. HBPE–COOH acted as a good antiscaling inhibitor for CaCO₃; when the polyester concentration was 200 mg/L, the scale inhibition rate exceeded 70%. Scanning electron microscopy and X‐ray powder diffraction demonstrated that the mechanism of inhibition was the disturbance of the growth of the crystals and modification of the crystal morphology by the hyperbranched polyester. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46292.     

Synthesis and characterization of a thermotropic liquid crystalline hyperbranched polyester

BACKGROUND: Hyperbranched polymers have received increasing attention in the fields of medicine, homogeneous catalysis and materials science. Hydroxyl‐functional aliphatic polyesters are one of the most widely investigated families of hyperbranched polymers. The research reported here is based on the preparation of a novel hyperbranched polyester and the modification of its terminal hydroxyl groups by biphenyl mesogenic units. RESULTS: 2,2,6,6‐Tetramethylolcyclohexanol as a core and 8‐[4′‐propoxy(1,1‐biphenyl)yloxy]octanoic acid as a mesogenic unit were synthesized. A hyperbranched polyester (HPE) was synthesized in one step and subsequently substituted by reaction of its terminal hydroxyl groups with the biphenyl mesogenic units to yield a novel liquid crystalline hyperbranched polyester (HPE‐LC). The chemical structures of all compounds were confirmed using Fourier transform infrared, ¹H NMR and ¹³C NMR spectroscopy. The thermal behavior and the mesogenic properties of the biphenyl mesogenic unit and HPE‐LC were investigated using differential scanning calorimetry, polarized optical microscopy and wide‐angle X‐ray diffraction. The results demonstrated that the degree of branching of the HPE is ca 0.63. Both HPE‐LC and the biphenyl mesogenic unit exhibit mesomorphic properties, but HPE‐LC has a lower isotropic transition temperature and a wider transition temperature range than the biphenyl mesogenic unit. CONCLUSION: A novel liquid crystalline hyperbranched polyester was successfully synthesized, which exhibits mesomorphic properties. This polymer has good solubility in highly polar solvents and good thermal stability. Copyright © 2009 Society of Chemical Industry     

含氟超支化聚酯的合成及其性能研究

利用十三氟辛酸对超支化聚酯进行端基改性,得到了含氟超支化聚酯。采用傅里叶变换红外光谱仪、差示扫描量热分析仪等对聚合物进行了表征和分析。结果表明:十三氟酸成功接枝到超支化聚酯上,含氟超支化聚酯的玻璃化转变温度为-20.5℃,含氟超支化聚酯溶液在固含量高达70%时仍具有较低的黏度,该聚合物成膜性好,涂膜的附着力为1级,柔韧性为1 mm,铅笔硬度2 H,抗冲击强度4.9 J/cm2,与水的接触角为105°,具有良好的表面疏水性。     

芳香-脂肪型超支化聚酯的合成及端基改性

以间苯二甲酸(IPA,A2型单体)和三羟甲基丙烷(TMP,B3型单体)为原料,对甲苯磺酸为催化剂,采用熔融聚合工艺制备了一种具有芳香-脂肪骨架的新型超支化聚酯(HBPE)。并以马来酸酐为反应试剂,对端羟基的HB-PE进行部分端基改性,得到了分子链末端既含有羟基又含有丙烯酸基的HBPE。研究了端基变化对HBPE的溶解性、特性黏数、玻璃化转变温度(Tg)和热稳定性的影响。结果表明,端基改性可使HBPE的溶解性变好,特性黏数从0.17 dL/g增加到0.19 dL/g,Tg从64℃降至60℃,热稳定性略微下降。     

含三嗪环的超支化聚酯丙烯酸酯的合成和应用

以丙烯酸甲酯和二乙醇胺为原料,制得N,N-二羟乙基-3-胺基丙酸甲酯（DAMP）;接着,用DAMP与三羟乙基异氰脲酸酯（THEIC）经酯交换反应,合成出一种超支化聚酯多元醇;再以该多元醇与丙烯酸通过酯化反应,制备了可UV固化的超支化聚酯丙烯酸酯。实验结果表明：以对甲苯磺酸为催化剂,当THEIC与DAMP的物质的量比为1∶9时,可制得二代超支化聚酯多元醇;该聚酯丙烯酸酯的玻璃化温度为53.0℃,与环氧丙烯酸酯（9104）混合组成的组合物,具有固化速度快、固化膜柔韧性佳的特点;附着力可达0级,摆杆硬度为0.751。     

Synthesis and Application of a Hyperbranched Polyester Quaternary Ammonium Surfactant

In the presence of the alkaline catalyst sodium hydroxide, the intermediate of hyperbranched polyester (H20Cl) was prepared by the modification of the hyperbranched polyester Boltorn H20 with epichlorohydrin. Then a new kind of quaternary ammonium functionalized hyperbranched polyester (H20C16 N) was synthesized by the reaction of H20Cl and hexadecyldimethylamine. The characteristics of H20C16 N were determined by FT‐IR, ¹H NMR and TGA. The molecular and molecular weight distribution of H20C16 N were determined by Gel Permeation Chromatography (GPC) and the surface activities of H20C16 N including surface tension (γ) and the critical micelle concentration (CMC) were measured at 25 °C. The H20C16 N reduced the surface tension of water to 30.81 mN/m at concentration levels of 7.94 × 10^?5 mol L^?1 and micellization free energies of the quaternary ammonium salt in its solution showed a good tendency towards adsorption at interfaces. The H20C16 N was applied to the silk fabric. An antimicrobial test of the treated fabrics against Escherichia coli and Staphylococcus aureus was carried out. SEM and XPS analysis were performed to study the dispersion of H20C16 N onto the fabric. All results exhibited excellent antibacterial properties of the hyperbranched polyester quaternary ammonium salt.     

Synthesis and application of long‐chain alkyl quaternary ammonium‐functionalized hyperbranched polyester

A novel kind of macromolecule, long‐chain alkyl quaternary ammonium functionalized hyperbranched polyester (QHPE), was synthesized by the reaction of hyperbranched polyester Boltorn H30 (H30) and 2,3‐epoxypropyl alkyl dimethyl ammonium chloride under alkaline conditions in dimethylformamide. After modification, the hydroxyl terminal group of H30 was converted into an ammonium functional group. A series of products was obtained with different lengths of an alkyl chain (C8, C12, C16, and C18) in the ammonium functional group. All of the products were characterized by Fourier transform infrared and NMR spectroscopy. The application of QHPEs as accelerators for the alkaline hydrolysis of poly(ethylene terephthalate) (PET) fabric was studied. The influences of the structure of QHPEs and hydrolysis conditions, such as alkaline concentration, hydrolysis time, and temperature, on the weight loss of PET fabrics were investigated. The results indicated that QHPE was a novel, efficient accelerator for the alkaline hydrolysis of PET fabrics. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and characterization of APTMS/melamine cured hyperbranched polyester-epoxy hybrid coatings

An epoxy-terminated hyperbranched polyester (EPHBP) was prepared by the reaction of hyperbranched polyester (HBP) and epichlorohydrin (EPH). Herein, we have synthesized a new kind of highly epoxy ended branched polyester to enhance the chemical bonding at the interfaces and to reduce the melt viscosity. The structural investigation of the hyperbranched polyesters was carried by spectroscopic techniques such as nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR) while molar masses were determined using gel permeation chromatography (GPC). The effect of the content of hexamethoxy methyl melamine (HMMA) and 3-amino propyltrimethoxysilane (APTMS) mixture on the thermal, mechanical and interfacial properties of EPHBP resins were also studied. The thermal, dynamic mechanical and mechanical properties of the heat cured coating films were also investigated. The combined analysis of the results indicate that the introduction of APTMS results in the enhancement of the thermal stability, glass-transition temperature (T_g), storage modulus, tensile strength and contact angle of the cured films. The improvement in properties depends on the APTMS content of the cured films. The cured films have also shown higher elongation at break due to the use of HMMA and presence of unmodified epoxide groups which indicates good flexibility and toughness of the coating films.     

A novel hyperbranched polyester functionalized with azo chromophore: synthesis and photoresponsive properties

Summary A hyperbranched polymer containing azo chromophores on the periphery has been synthesized from transesterification reaction between a hyperbranched polyester bearing peripheral hydroxyl groups and ethyl 4-{4'-[N, Ndi(hydroxyethyl)aminobutoxy]phenylazo}benzoate. The hyperbranched polyester was obtained by adding the AB₂ monomers step by step to a multifunctional core molecule. Narrow molecular weight distribution, with a polydispersity index as low as 1.1, was achieved by this method. The azobenzene- functionalized hyperbranched polymer as well as the corresponding azo monomer showed typical photoresponsive behavior of an azobenzene type molecule. The trans azobenzene units of the hyperbranched polymer could be reversibly switched by UV irradiation to the cis form that recovered slowly to the trans form in the dark. However, significantly less conversion from the trans isomer to the cis isomer was observed for the azobenzenefunctionalized hyperbranched polymer at the photostationary states under the irradiation of UV light, which could be attributed to the increased steric hindrance in the hyperbranched polymer. Received: 1 April 2002 /Revised version: 10 July 2002/ Accepted: 15 July 2002