对叔丁基苯甲酸改性超支化聚酯的合成和性能

以三羟甲基丙烷(TMP)为核,二羟甲基丙酸(bis-MPA)为AB2型单体,合成超支化聚酯(HBPE)。采用对叔丁基苯甲酸(PTBA)对其进行改性,得到PTBA取代度为10%~75%的超支化聚酯(HBP-10M~HBP-75M,统称HBP-Ms)。通过傅里叶变换红外光谱(FTIR)、核磁共振氢谱(1HNMR)和凝胶渗透色谱(GPC)对产物结构和相对分子质量(简称分子量,下同)进行表征,并考察HBP-Ms的溶解性和涂膜性能。研究结果表明,合成了支化度为0.47的HBPE,改性后的HBP-Ms具有良好的溶解性,可溶解在丙酮、DMF、乙酸乙酯、乙醚、苯和二甲苯,不溶于正己烷。HBP-Ms涂膜具有较高的硬度、光泽度和柔韧性,其中HBP-10M和HBP-25M具有更优异的溶解性和涂膜性能。TGA分析表明,PTBA可提高改性树脂涂膜的热稳定性。     

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。     

Boltorn型超支化聚酯对PHBV的增韧改性研究

以对甲苯磺酸(p?TSA)为催化剂，三羟甲基丙烷(TMP)为核、2，2?二羟甲基丙酸(DMPA)AB2型单体为主要原料，采用“一步法”合成了Boltorn型超支化聚酯(HBPE)；以HBPE为改性剂，以三氯甲烷为溶剂，通过溶液法对聚(3?羟基丁酸酯?co?3?羟基戊酸酯) (PHBV)树脂进行改性，并通过差示扫描量热仪、力学性能测试、热台偏光显微镜、热重分析仪、扫描电子显微镜等分析方法对其进行表征。结果表明，随着HBPE加入量的增加，PHBV体系的玻璃化转变变得越来越明显，表明HBPE的加入显著增强了PHBV的链段运动能力；当HBPE添加量为4份时，PHBV体系的结晶度由64.77 %下降至27.68 %，断裂伸长率提高了194.04 %，拉伸强度提高了27.22 %，撕裂强度提高了56.28 %；HBPE的加入，在保持PHBV树脂拉伸强度小幅增强的基础上，使得PHBV的断裂韧性得到明显提升；HBPE是一种优良的PHBV增韧改性材料。     

复合改性水性聚氨酯乳液的合成及表征

以甲苯二异氰酸酯(TD I)、聚醚二元醇(N220)、1,4-丁二醇(BDO)和二羟甲基丙酸(DMPA)为原料,采用丙酮法合成了水性聚氨酯(WPU)分散体。在此基础上,采用三羟甲基丙烷(TMP)对其进行了交联改性并通过环氧树脂和丙烯酸酯对其进行共聚改性,制得了以丙烯酸酯为核,聚氨酯为壳的核壳交联型水性聚氨酯分散体。通过乳液粒度、黏度和涂膜的耐水性和硬度、接触角等分析以及透射电镜观测研究了二羟甲基丙酸(DM-PA)、TMP、环氧树脂以及MMA用量对水性聚氨酯涂膜耐水性等性能的影响,确定了最佳物料配比。结果表明,当DMPA、E-20、TMP和MMA在聚氨酯水性分散体中的质量分数分别为7.5%、6%、1%和20%时,合成的水性聚氨酯乳液平均粒径80 nm,黏度适中,胶膜的物理力学性能较好,耐水性提高。     

支化PET的非等温结晶性能研究

采用直接酯化缩聚法,以3-羟甲基丙烷(TMP)或季戊四醇(PER)为支化剂,制备支化PET;探讨了支化剂对其结晶性能的影响;利用差示扫描量热(DSC)法研究了支化PET的非等温结晶性能。结果表明:支化剂TMP或PER的加入可以有效增强PET的结晶能力,但过量的支化剂会抑制PET的结晶;支化PET的非等温结晶Avrami指数为3.03~4.42,其结晶机理为均相成核和异相成核相结合;支化PET的结晶活化能比常规PET的低,支化PET结晶对温度的依赖性降低。     

以缩水甘油醚为核的星形羟基聚酯的合成及其涂膜性能

以三羟甲基丙烷三缩水甘油醚(TMPGE)为核分子,利用AB2型单体2,2-二羟甲基丙酸与ε-己内酯开环反应产物及一元羧酸的羧基与TMPGE的环氧基反应,合成了系列星形羟基聚酯(SHPs),研究了一元羧酸种类及原料配比对SHPs性能的影响。采用FTIR、1H NMR对SHPs的分子结构进行表征,用GPC对其相对分子质量及分布进行了测试,并考察了其溶液黏度和特性黏度。测试了以甲苯二异氰酸酯/三羟甲基丙烷(TDI/TMP)加成物为固化剂制备的SHPs漆膜性能。SHP-2的溶液黏度低至220 m Pa·s(80%固含),用其制备的高固含涂料VOC低于320 g·L-1,其漆膜具有优异的附着力、柔韧性和较高的硬度。     

端环氧型超支化聚酯对聚（3-羟基丁酸戊酸共聚酯）的改性研究

以2,2二羟甲基丙酸（DMPA）和三羟甲基丙烷（TMP）为原料,以对甲苯磺酸（P-TSA）为催化剂,通过“一步法”合成三代超支化聚酯（HBPE）,然后采用环氧氯丙烷对HBPE进行改性,得到了具有端环氧基的三代超支化聚酯（EHBP-G3）目标产物,最后采用熔融共混法制备了EHBP改性的聚（3-羟基丁酸酯-co-3羟基戊酸酯）（PHBV）树脂;通过差示扫描量热仪、偏光显微镜、力学性能和熔体流动速率等分析方法对制备的PHBV/EHBP共混物进行表征。结果表明,加入1.5 %(质量分数,下同)三代超支化聚酯（EHBP-G3）时,PHBV/EHBP共混物的结晶度下降了16.1 %,冲击强度提高了34.3 %。     

亚乙基苊镍催化剂催化乙烯溶液聚合制备超支化聚乙烯

以一种亚乙基苊(α-二亚胺)镍配合物为主催化剂,研究了温度、压力、助催化剂及其用量等对乙烯溶液聚合制备超支化聚乙烯(HBPE)的影响,并对HBPE的结构与性能进行分析。结果表明:随着温度或压力的升高,催化剂活性均呈现先升高后下降的趋势;HBPE的相对分子质量随温度的升高而下降,而支化度与温度呈正比,与压力呈反比;二氯乙基铝、三乙基铝和甲基铝氧烷均可作为该催化剂的助催化剂,使用二氯乙基铝时的催化剂活性最高,所制HBPE的支化度也最高。     

自缩合可逆络合聚合制备支化聚甲基丙烯酸甲酯

以对氯甲基苯乙烯(VBC)和碘化钠(NaI)反应原位生成引发剂单体,经自缩合可逆络合聚合(SCVP-RCMP)一步法制备了支化聚甲基丙烯酸甲酯。通过核磁共振(NMR)和三检测凝胶渗透色谱(TD-GPC)对聚合物和聚合反应过程进行了分析和表征。结果表明,模型化合物苄氯(BzCl)在80℃与碘化钠(NaI)反应10 min就完全转化成苄碘。VBC能与NaI反应并成功引发MMA发生RCMP,MMA的转化率高达98.1%,所得聚合物特性黏度低于同分子量下线型聚合物的特性黏度,具有明显的支化结构。聚合物支化度随NaI用量的增加而增加。对反应过程研究表明,聚合反应6 h之前具有"活性"可控的特点,反应时间延长,聚合物支化度增加。     

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。     

一种用于喷墨墨水的超支化聚合染料的合成研究(英文)

本论文采用一步法,以季戊四醇作为B4核单体、2,2-二羟甲基丙酸作AB2型单体合成了超支化聚酯内核(HBPE),并对产物进行表征,计算超支化聚酯的支化度为0.41;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。采用月桂酸改性超支化聚酯合成了新的长链烷基化的超支化聚合物(LHBP),并用红外和核磁共振谱图进行结构表征。溶解性质表明月桂酸改性超支化聚酯溶解于极性较弱的溶剂中,较未改性的超支化聚酯具有更好的有机溶剂溶解性。采用改性后的超支化聚酯内核(LHBP)和2-羟乙胺基蒽醌,通过IPDI偶联法合成了超支化聚合染料(R-LHBP)。     

Effect of the degree of branching on the glass transition temperature of polyesters

Glass transition temperature dependence on the branching degree can be empirically estimated by excluding additional effects on this parameter as molecular weight distribution, end group interactions or crystallization. In this communication aliphatic–aromatic polyesters with a well defined degree of branching between 0% (linear) and 50% (hyperbranched) are investigated by differential scanning calorimetry. The hydrogen bonding effect of the OH-terminal groups was successfully extracted from the pure branching effect by protection of the end-functionalities. Fractionation of samples with variation of the branching degree and end-functionalities led to series of narrowly distributed molar masses. The dependence of the molecular weight on the glass transition temperature for different branching degrees was calculated and compared for polar and non-polar end groups.     

UV固化水性高支化聚酯

以偏苯三酸酐(TMA)、环氧氯丙烷(ECH)、甲基丙烯酸缩水甘油酯(GMA)、三乙胺(TEA)合成了末端羧基与氨基不同比例的一系列可UV固化的高支化聚酯,研究了末端官能团对合成产物水溶性、粘度以及凝胶转化率的影响。结果表明:高支化聚酯的水溶性随着末端的羧基增多而变大,光固化速度与末端的丙烯酰基官能度有关。水作为溶剂引入10%后,可以将树脂的粘度从6500mPa·s降低到3200mPa·s。     

Study on hyperbranched polyesters as rheological modifier for Spandex spinning solution

The rheological behavior of polyurethane (PU)/N,N‐dimethylformamide (DMF) spinning solutions with various contents of hyperbranched polyesters was studied using a RS150L‐controlled stress rotational rheometer. The results showed that the viscosity of the spinning solutions could be greatly reduced by adding hyperbranched polyesters even at 0.5 wt% loading. The zero‐shear viscosity of solutions with hyperbranched polyesters was much lower than that of pure PU/DMF solution, which indicated a lower degree of entanglement when solutions were in a static state. The apparent activation energy of viscous flow and the critical shear rate for shear thinning of solutions with hyperbranched polyesters were much lower than that for pure PU/DMF solution, which indicated a weaker entanglement structure formed. In addition, the effect of hyperbranched polyesters on the mechanical properties of Spandex fiber was discussed. Copyright © 2006 Society of Chemical Industry     

Rheology of concentrated solutions of hyperbranched polyesters

The solution rheology of different generations of hyperbranched polyesters in N‐methyl‐2‐pyrrolidinone (NMP) solvent was examined in this study. The solutions exhibited Newtonian behavior over a wide range of polyester concentrations. Also, the relative viscosities of poly(amidoamine) (PAMAM) dendrimers in ethylenediamine were compared with those of the hyperbranched polyesters in NMP. Both types of dendritic polymers have relative viscosities that are exponential functions of their molar fraction in solution. The slopes of these relative viscosity curves show a linear relationship with respect to the generation number. PAMAM dendrimers have the greater slopes for each generation, reflecting their relatively larger intrinsic viscosity values.     

NMR and MALDI-TOF MS study of side reactions in hyperbranched polyesters based on 2,2-bis(hydroxymethyl)propanoic acid

Hyperbranched polyesters of 2,2-bis(hydroxymethyl)propanoic acid (BMPA) with various molar ratios of tetra(hydroxymethyl)methane (PE) core molecule were characterized by NMR spectroscopy and MALDI-TOF mass spectrometry. In all polyesters, the formation of ether groups was observed. The extent of etherification increased with increasing PE content. This was assigned to a higher reactivity of PE towards etherification than BMPA. Intra- and intermolecular etherifications and intramolecular esterifications were detected by MALDI-TOF MS on the core molecule-containing polyesters, resulting in the formation of cycle-containing hyperbranched molecules. The ratio of cycle-containing molecules reached 50% at high reaction time for the polyester without core molecule, but was much lower for the polyesters containing a core molecule. As a consequence of these side reactions, the control of hyperbranched polyester molar mass by varying the core molecule (chain limiter) molar ratio is much more difficult than for linear polyesters.     

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     

Investigation into the solution properties of hyperbranched polymer

The solution properties of hydroxyl terminated hyperbranched aliphatic polyesters and their acetyl derivatives have been studied by measuring viscosity parameters. The polarity of terminated groups of molecules is the most important factor affecting their properties. The intrinsic viscosity [η] cannot reflect the real monomolecular hydrodynamic volume of hydroxyl group-terminated hyperbranched polymer due to the strong intermolecular forces which lead to the formation of stable clusters. The intermolecular association constant K_M depends not only on molecular weight, but also on the polarity of end-groups. However, the dynamic contact concentration C_S can be determined accurately from reduced viscosity versus concentration plots. The reason why the intrinsic viscosity does not change linearly with the generation of the hyperbranched aliphatic polyesters is explained using ‘free-draining’ and ‘non-draining’ models. © 2001 Society of Chemical Industry     

Solution properties of selectively modified hyperbranched polyesters

Simultaneous characterization of the degree of branching and molar mass on a molecular level for hyperbranched polymers is still strongly limited. Therefore model hyperbranched polyesters for development of new chromatographic techniques on the basis of 2,2-bis(hydroxymethyl)propionic acid were synthesized. The two types of OH-functionalities (linear and terminal) of the hyperbranched polymer were selectively modified using different protection groups. The modification of the terminal end groups was carried out using their diol character with the formation of a ketal ring without changing the chemical structure of the linear OH groups. In order to obtain completely non-polar polymer, the linear OH-units were functionalized with an acetyl group. The last modification step was the deprotection of the terminal end groups by removing the ketal ring. Fractions with various molar masses for each modification stage were obtained by preparative fractionation. Extensive characterization by SEC-MALLS, NMR spectroscopy, and viscosity measurements elucidated the dependence of the molecular shape in solution on the polarity. These results were supported by molecular dynamic simulations.     

核分子比例对超支化聚酯结构和涂膜性能的影响

以双季戊四醇为核,二羟甲基丙酸为单体合成了不同代数的超支化聚酯。采用了IR、GPC、13C NMR、DSC和化学滴定等方法对产物进行了表征和分析。试验结果表明聚合物具有较小的多分散性指数(拟两代超支化聚酯M—w/M—n=1.159,拟四代超支化聚酯M—w/M—n=1.028)。通过聚合物的13C NMR分析了超支化聚酯的支化度,表明在超支化聚酯中,端羟基的反应活性大于线性单元中羟基的活性。并用油酸对聚合物进行改性,研究了固含量与黏度的关系及其涂膜的性能;结果表明该树脂具有良好的成膜性和涂膜性能。