聚对苯二甲酸-共-丁二酸丁二醇酯的研究及产业化现状

介绍了生物可降解材料脂肪族/芳香族共聚酯聚对苯二甲酸-共-丁二酸丁二醇酯(PBST)的合成工艺技术及基本性能,综述了近年来国内外PBST的研究现状和产业化现状.PBST的合成工艺主要是酯交换法和直接酯化法,酯交换法原料成本高、副产物分离较难、合成的PBST相对分子质量低;直接酯化法可以得到纯度较高的PBST,副产物只有...     

聚丁二酸丁二醇-共-对苯二甲酸丁二醇酯的热降解动力学

在高纯氮气保护下,采用不同的升温速率,用热失重法对聚丁二酸丁二醇-共-对苯二甲酸丁二醇酯(PBST)共聚酯的热降解行为和热降解动力学进行了研究。用Kissinger、Flynn-Wall-Ozawa及Friedman 3种方法对比计算了PBST共聚酯在氮气气氛中的热降解活化能,并对PBST共聚酯的热老化寿命进行了探讨。结果表明在氮气气氛中共聚酯的热稳定性随BT含量增加而增强,不同组分的PBST共聚酯热降解均为1级反应,分解活化能E均随BT摩尔分数的增加而增大。     

CHDA改性PBT的制备及其结构与性能研究

以精对苯二甲酸(PTA)、1,4-丁二醇(BDO)和1,4-环己烷二甲酸(CHDA)为原料,通过直接酯化法制得CHDA改性聚对苯二甲酸丁二醇酯(PBT)共聚酯,研究了CHDA含量对改性PBT共聚酯的结构和性能的影响。结果表明：随着CHDA含量的增加,改性PBT共聚酯的缩聚时间延长,特性黏数提高;CHDA的加入对改性PBT共聚酯的熔点、熔融结晶峰温度、结晶度的影响较大,当CHDA质量分数为20%,改性PBT共聚酯的熔点降至190.68℃,熔融结晶峰温度降至140.49℃,结晶度降至17.42%;改性PBT共聚酯的热稳定性略低于常规PBT,当CHDA质量分数为20%,改性PBT共聚酯的热分解峰值温度降至399.25℃;随着CHDA含量的增加,改性PBT共聚酯的拉伸强度、弯曲强度降低,断裂伸长率、冲击强度升高,当CHDA质量分数为5%～10%时,改性PBT共聚酯的综合性能较优,拉伸强度为40.65～44.11 MPa,断裂伸长率为143.23%～218.85%,冲击强度为5.12～5.88 kJ/m²,弯曲强度为45.15～51.31 kJ/m²。     

CHDA改性PET共聚酯的制备及性能研究

为了研究1,4-环己烷二甲酸(CHDA)改性PET的应用,通过差示扫描量热、热失重、万能材料试验机和摆锤冲击试验机等对CHDA改性PET共聚酯的常规性能、结晶性能、冲击性能等进行了表征,结果表明:随着CHDA用量增加,共聚酯熔体的动力黏度降低,特性黏度升高;共聚酯的端羧基、二甘醇含量逐渐升高;共聚酯的玻璃化转变温度T_g、熔融结晶峰温T_(mc)、熔点T_m逐渐降低,冷结晶峰温T_c逐渐升高;用量5%时,共聚酯的拉伸强度最大,同时冲击强度也增强。可以看出,CHDA的引入使熔体动力黏度降低,有利于提高共聚酯的特性黏度、制品的拉伸强度,降低共聚酯的熔点、结晶速度,以上变化均有益于后道加工过程,且CHDA最佳用量为5%。     

染色改性共聚酯的可纺性及其纤维结构性能研究

在聚对苯二甲酸乙二醇酯(PET)分子链上分别引入聚醚、间苯二甲酸乙二醇酯-5-磺酸钠(SIPE)、脂肪酯类,得到染色改性共聚酯(简称共聚酯);将共聚酯进行纺丝、拉伸,制得共聚酯纤维,讨论了共聚酯的可纺性;利用差示扫描量热分析仪、X射线衍射(XRD)仪等研究了共聚酯纤维的结构与性能。结果表明:通过纺丝工艺调整,共聚酯均具有良好的可纺性能;与PET的XRD光谱相比,共聚酯3个主晶面■的衍射峰位置基本没有改变;相比PET纤维,共聚酯纤维的取向度和结晶度以及断裂强度和伸长率有不同程度的下降,而沸水收缩率上升;单体SIPE和柔性链的加入明显改善了共聚酯纤维的染色性能,其上染率和染色深度(K/S值)显著提高,其中醚型和酯型常压阳离子染料可染共聚酯的上染率均大于97%,K/S值均大于28。     

癸二酸改性PET共聚酯的合成与性能研究

采用癸二酸(SA)、对苯二甲酸(PTA)、乙二醇(EG)进行熔融缩聚反应,合成了不同含量SA改性PET共聚酯,探讨了SA添加量对改性PET共聚酯的聚合过程及常规性能指标的影响,对其拉伸和弯曲性能进行了表征。结果表明:随SA用量的增加,所得改性PET共聚酯的特性黏度逐渐增大,且其端羧基(COOH)、玻璃化转变温度(T_g)、冷结晶峰温度(T_c)、熔融结晶峰温度(T_(mc))和熔点(T_m)等指标均呈下降趋势;拉伸强度变化不大,断裂伸长率逐渐变大;弯曲强度与弯曲模量在SA含量超过5%后呈下降趋势。     

聚对苯二甲酸-丁二酸丁二醇酯流变性能及复合纺丝工艺研究

本文采用毛细管流变仪研究了聚对苯二甲酸-丁二酸丁二醇酯(PBST)和聚对苯二甲酸丁二酯(PBT)流变性能，分析两种熔体在不同剪切速率和温度下动力黏度及匹配度。在动力黏度匹配较好的工艺下，对PBT和PBST进行并列复合纺丝，并牵伸，评价纤维卷曲性能。结果表明：PBST共聚酯非牛顿指数较小，表观黏度受剪切速率的影响较PBT大。两种熔体的结构程度及两者结构化程度的差异均随着温度的升高而减小，说明升高温度可提高复合可纺性。PBST共聚酯黏流活化能受剪切速率的影响较PBT小。复合纤维最佳纺丝工艺：PBST与PBT质量比为5:5,PBST螺杆进料温度210℃,PBT螺杆进料温度255℃,纺丝箱体温255℃,牵伸温度85℃,制备的纤维具有很好的自卷曲性能。     

脂肪-芳香族共聚酯PBST合成的共酯化工艺

为利用现有的三釜工业聚酯装置合成脂肪-芳香族共聚酯(PBST),对其共酯化动力学及工艺进行了研究。结果表明,共酯化前期主要是丁二酸(SA)的酯化,后期主要是对苯二甲酸(TPA)的酯化,具有与"平行"酯化相接近的动力学特点;采用共酯化-共缩聚工艺合成PBST具有可行性。温度、醇酸物质的量之比(醇酸比)、催化剂用量对共酯化反应有明显的影响。采用钛酸四丁酯-乙酰丙酮镧[TBT-La(acac)3]双组份催化剂(Ti与La的物质的量比为1),在共酯化温度210℃、醇酸比2、催化剂用量0.1%(摩尔分数)的条件下,共酯化2 h、共缩聚1 h,可制得特性粘数1.2 d L/g、色泽良好的PBST共聚酯树脂。     

1,4-环己烷二甲醇改性PBT共聚酯的热性能研究

以对苯二甲酸(PTA)、1,4-丁二醇(BD)和1,4-环己烷二甲醇(CHDM)为主要原料,制备了一系列CHDM改性聚对苯二甲酸丁二醇酯(PBT)共聚酯。采用差式扫描量热仪(DSC)和热重分析仪(TGA)等分析方法测试了共聚酯的性能,研究了不同CHDM含量对共聚酯热性能和结晶性能的影响。结果表明:随CHDM含量的增加,共聚酯玻璃化转变温度逐渐升高;共聚酯的熔点先降低后升高,CHDM/PTA摩尔比为40%时熔点最低;随CHDM含量的增加,共聚酯的结晶性能逐渐减弱。     

聚丁二酸丁二醇-共-对苯二甲酸丁二酯流变性能研究

采用毛细管流变仪研究了聚丁二酸丁二醇-共-对苯二甲酸丁二酯(PBST)的流变性能。结果表明:PBST熔体为切力变稀型流体,黏流活化能较低,具有较好的成纤性能。同时,讨论了相对分子质量、剪切速率、温度对PBST熔体流动曲线、非牛顿指数、结构黏度指数等的影响,为生物可降解性PBST纤维的生产工艺提供了理论依据。     

Mechanical,thermal properties and isothermal crystallization kinetics of biodegradable poly(butylene succinate-<Emphasis Type="Italic">co</Emphasis>-terephthalate) (PBST) fibers

Biodegradable copolymer poly(butylene succinate-co-terephthalate) (PBST), with 70 mol% butylene terephthalate (BT), was melt-spun into fibers with take-up velocity of 2 km/min. The mechanical and thermal properties of the as-spun fibers were investigated through tensile test, DSC and TGA. Compared to poly(butylene terephthalate) (PBT) fibers, PBST fibers exhibited lower initial tensile modulus and higher tensile elongation at break which indicated their better flexibility. DSC results showed high melting temperature (ca.180.7 °C) of PBST fibers helpful to the textile processing compared to other biodegradable polyesters. Furthermore, isothermal crystallization behaviors of PBST fibers at low and high supercoolings were investigated by DSC and DLI, respectively. The measurement of crystallization kinetics at low supercoolings indicated that Avrami exponent n for PBST fibers was at a range of 2.9 to 3.3, corresponding to the heterogeneous nucleation and a 3-dimensional spherulitic growth. Similar results were given for isothermal crystallization behavior at high supercoolings investigated by DLI technique. Additionally, the equilibrium melting temperature of PBST fibers was obtained for 206.5 °C by Hoffman-Weeks method. Further investigation through DLI measurement provided the temperature at maximum crystallization rate for PBST fibers located at about 90 °C, which was very useful to polymer processing.     

The thermal,mechanical and viscoelastic properties of poly(butylene succinate-<Emphasis Type="Italic">co</Emphasis>-terephthalate) (PBST) copolyesters with high content of BT units

Poly(butylene succinate-co-terephthalate) (PBST) copolyesters, with rigid butylene terephthalate (BT) units varying from 50 to 70 mol%, were synthesized via direct esterification route. The chemical structure and comonomer composition were characterized by ¹H NMR. The weight-average molecular weights (M _w ) of the prepared products measured by GPC spanned a range of 1.39 × 10⁵–1.93 × 10⁵ with corresponding M _w /M _n value of 2.23–2.42. Based on the WAXD analysis, PBST copolyesters were identified to have the same crystal structure as that of poly(butylene terephthalate) (PBT). The researches on the thermal properties showed that the melting temperature and decomposed temperature of PBST copolyesters increased with the increasing content of rigid BT units through DSC and TGA measurement. Furthermore, the tensile test results presented that the copolyester with higher content of BT units had higher initial modulus, higher breaking strength but lower elongation at break. Additionally, the viscoelastic properties of the prepared PBST films were analyzed by DMA measurement. It was found that both storage modulus (E′) and loss modulus (E″) corresponding to the peak tended to heighten with the increase of BT units, indicating the copolyester with higher BT units content had the more prominent viscoelasticity. The peak of loss factor (tan δ) curve shifted to higher temperature as the content of rigid BT units increased due to the increasing of the glass transition temperature (T _g).     

生物可降解共聚物PBST和PBS的结构与结晶性能

利用核磁共振氢谱和广角X射线衍射法研究了生物可降解共聚物聚对苯二甲酸-共-丁二酸丁二醇酯(PBST)的结构及结晶性能,并与聚丁二酸丁二醇酯(PBS)进行比较。结果表明:PBST为无规共聚物,其晶体结构为三斜晶系,PBS为均聚物,为单斜晶系,PBST的结晶度和结晶尺寸均比PBS的小。     

Miscibility and crystallization behaviors of biodegradable poly(butylene succinate‐co‐butylene terephthalate)/phenoxy blends

Miscibility and crystallization behaviors of biodegradable poly(butylene succinate‐co‐butylene terephthalate) (PBST)/poly(hydroxyl ether biphenyl A) (phenoxy) blends were investigated with various techniques in this work. PBST and phenoxy are completely miscible as evidenced by the single composition‐dependent glass transition temperature over the entire blend compositions. Nonisothermal melt crystallization peak temperature is higher in neat PBST than in the blends at a given cooling rate. Isothermal melt crystallization kinetics of neat and blended PBST was studied and analyzed by the Avrami equation. The overall crystallization rate of PBST decreases with increasing crystallization temperature and the phenoxy content in the PBST/phenoxy blends; however, the crystallization mechanism of PBST does not change. Moreover, blending with phenoxy does not modify the crystal structure but reduces the crystallinity degree of PBST in the PBST/phenoxy blends. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis of 3,13-diglycidyloxypropyloctaphenyl double-decker polyhedral oligomeric silsesquioxane and the thermal reaction properties with thermosetting phenol-formaldehyde resin

3,13-Diglycidyloxypropyloctaphenyl double-decker silsesquioxane (EP-DDSQ) was synthesized by process of alkaline hydrolysis condensation of phenyltrimethoxysilane and corner capping reaction of methyldichlorosilane, followed by hydrosilylation with allyl glycidyl ether, and the resultant structure was confirmed by fourier transform infrared spectrometer (FTIR) and nuclear magnetic resonance (NMR), respectively. The thermosetting phenol-formaldehyde (PF) resin was then modified by EP-DDSQ, and the reactivity of PF resin with EP-DDSQ and thermal pyrolysis of modified cured resin were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The surface morphologies of modified resins at high temperature were characterized with field emission scanning electron microscope (FESEM), and chemical structure of modified resins was analyzed through X-ray photoelectron spectrometer (XPS). The results showed that the appropriate addition of EP-DDSQ did not affect the curing temperature of the PF resin itself, but could improve the heat resistance of the system. When the amount of EP-DDSQ added was 10%, the initial degradation temperature of PF resin was increased by 49.31°C, and when the amount of EP-DDSQ added was 16%, the char yield of which was reached up to 61.39%, compared with that of pure PF resin (TGA_1,000°C of 57.62%) at Ar atmosphere. More importantly, the modified resin formed a regular and dense layer of SiC and SiO_x ceramic on the surface after ablation in the muffle furnace at 800°C air atmosphere, which is very important for ablative resistant materials.     

Physical characterization of poly(glycerol sebacate)/Bioglass® composites

Differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA) and X‐ray diffraction have been used to characterize the structure of a crosslinked polyester (poly(glycerol sebacate), PGS), prepared from a molar ratio of a diacid (sebacic acid) and a triol (glycerol), and their composites formed with an alkaline reactive filler, Bioglass^®. The Bioglass reacts with the sebacic acid carboxylate groups during the composite synthesis, resulting in elastomers that are linked by ionic and covalent crosslinks. Due to its relatively low crosslink density, the unfilled PGS polymer can crystallize below room temperature but is an amorphous elastomer at room temperature. The DSC results show that the Bioglass composites are also semicrystalline below room temperature but the crystallinity is disrupted by the ionic linkages. DMTA of the dry PGS and PGS‐Bioglass composites confirms the semicrystalline nature of the materials and comparison with specimens that had been saturated with water vapour shows that the ionic crosslinks are dissociated by hydration by water molecules. Copyright © 2011 Society of Chemical Industry     

1,4-双-(4''''卤苯酰基)苯合成及提纯改进的研究

以对苯二甲酰氯和卤代苯为单体,无水氯化铝粉末为催化剂合成了1,4-双-(4'卤苯酰基)苯.运用改进的方法提纯得到精制品1,4-双-(4'卤苯酰基)苯,收率96%.并通过1H NMR和DSC对产物进行表征,测试结果与目标产物相吻合.     

双苯并噁嗪树脂的合成与固化性能研究

采用溶液法和无溶剂法两种不同的工艺制备苯并噁嗪预聚体,利用红外光谱(FT-IR)法和核磁共振(1H NMR)法对其结构进行了表征,并使用差示扫描量热(DSC)法研究其固化过程。实验结果表明,该苯并噁嗪预聚体具有较高的成环率;其近似凝胶温度为182℃,固化温度为198℃,后处理温度为246℃。     

FTIR、MASNMR和TG-DSC法研究分子筛表面接枝的硅烷基团

采用三甲基氯硅烷对介孔分子筛KIT-1进行了表面修饰。利用X射线粉末衍射(XRD)对样品进行了结构分析,用傅里叶变换红外光谱(FT IR)和核磁共振谱(MAS NMR)辅助热重-示差扫描量热(TG-DSC)法研究了硅烷基团在分子筛表面的情况。研究结果表明,表面修饰在保持分子筛介孔结构的同时,使硅烷基团成功接枝在分子筛孔道表面,热分析显示表面修饰样品失重6.14%,硅烷基团热分解时吸热577.9 J/g。