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。     

钛基催化聚酯研究

对自制钛基聚酯催化剂在聚合工艺及合成产品性能方面进行了研究。结果表明,该钛催化剂用于聚酯生产时,可以生产出具有低二甘醇含量、较高的玻璃化转变温度和熔点的聚酯。     

PETG共聚酯的合成及性能研究

以对苯二甲酸(PTA)、乙二醇(EG)和1,4-环己烷二甲醇(CHDM)作为原料，经过酯化缩聚制备聚对苯二甲酸乙二醇酯-1,4-环己烷二甲醇酯(PETG)。研究CHDM质量含量(0～20%)对PETG共聚酯酯化和缩聚过程的影响，同时利用热失重分析(TGA)、差示扫描量热仪(DSC)等对PETG共聚酯的常规性能、热性能进行分析。结果表明，在等负荷和相同原料醇酸比的条件下，随着CHDM添加量的增加，酯化水馏出量逐渐下降，但酯化速率变化不大；共聚酯的缩聚反应速率在聚合后期呈下降趋势；随着CHDM添加量的增加，二甘醇的含量逐渐减少，玻璃化转变温度上升，熔点降低；氮气氛围下，聚酯的失重量逐渐增大，表明PETG的热稳定性逐渐降低。     

丙三醇对PBST共聚酯结构和性能的影响

基于生物可降解性聚酯——聚丁二酸-共-对苯二甲酸丁二醇酯(PBST),通过原位添加不同含量的丙三醇作为第四单体,制备出共聚改性的PBST共聚酯。通过核磁共振仪(NMR)、差示扫描量热仪(DSC)、广角X射线衍射仪(WAXD)及接触角测试,分别对PBST共聚酯的结构和性能进行了研究。结果表明:丙三醇的加入并没有改变PBST共聚酯的化学组成和结构;随着丙三醇含量的增加,共聚酯的玻璃化转变温度先上升后下降,而熔点是逐步降低的;改性前后和拉伸前后PBST的晶型均未发生变化,但分子结构的规整性受到破坏,且发生拉伸诱导取向;改性PBST共聚酯的亲水性能较纯PBST有明显提高。     

含磷共聚酯的合成及性能研究

用添加含磷共聚单体法合成了三种新四的含磷共聚酯。对萃洗后的反应产物进行了红外测试，对合成的反应条件进行了初步研究，并对所得产物的性能进行了对比。结果表明，含磷共聚单体的引入使共聚酯的玻璃化转变温度和熔点较聚酯降低，而冷结晶温度和结晶速度的变化则随引入的改性组分的不同而异。共聚酯的阻燃性、抗静电性均得到改善，染色性能也有所改善，表明该类共聚酯有可能用于制备多功能涤纶。     

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%。     

PET-PCT共聚酯的制备及其热性能研究

由直接酯化法制备了不同1,4-环己烷二甲醇(CHDM)含量的聚对苯二甲酸乙二醇酯-聚对苯二甲酸-1,4-环己烷二甲醇酯(PET-PCT)共聚酯;利用核磁共振表征了合成产物的实际组成及序列结构;采用差示扫描量热和热失重分析研究了共聚酯的结晶特性和热稳定性。结果表明:合成的共聚酯为无规嵌段聚合物,PCT的实际组成均高于投料比,各链段的序列长度与其含量成正比。随着CHDM含量的增加,共聚酯的玻璃化转变温度升高,退火后的试样在低温处和高温处出现了两个熔点,且熔点和焓值随PCT含量的增加而降低。合成产物热稳定性优良,起始分解温度均大于400℃,最大分解温度大于435℃。用Friedman法对热分解动力学的分析,进一步证明共聚酯的热稳定性优良。     

相容剂对EVA/无卤阻燃共聚聚酯合金性能的影响

以高熔体流动速率聚合物(150-W)作为乙烯-醋酸乙烯酯共聚物(EVA)/无卤阻燃共聚聚酯(P-PET)合金的非反应性相容剂,采用熔融挤出法制备了以EVA为基体的EVA/P-PET合金,并研究了150-W对合金性能的影响。结果表明,150-W提高了合金的综合性能,EVA/P-PET/150-W配比为60/30/10时,拉伸强度和断裂伸长率比不含150-W的体系分别提高了148.4%和283.1%,同时改善了合金的加工性能;少量150-W(≤10%)的加入对合金的阻燃性能无明显影响;150-W的加入促进了界面层的形成,增强了界面处的粘接,从而提高了体系相容性;150-W的加入使P-PET的玻璃化转变温度向EVA的玻璃化转变温度靠近。     

聚(对苯二甲酸丁二醇-co-ε-己内酯)的合成、表征及力学性能研究

以聚对苯二甲酸丁二醇酯(PBT)和ε-己内酯(CL)为原料,通过PBT端羟基引发CL开环聚合,然后在高温、高真空条件下缩聚,制备了不同硬段含量的聚(对苯二甲酸丁二醇-co-ε-己内酯)共聚酯(PBT-CL)。通过1H NMR、IR、DSC等对PBT-CL进行了表征。结果表明PBT-CL具有嵌段聚合物特性。随硬段含量升高,共聚酯熔点和结晶温度上升,共聚酯的密度、拉伸强度、弯曲强度逐渐增大。硬段序列长度随硬段含量增加而增加。     

聚乙二醇(PEG)改性嵌段共聚酯的热性能研究

采用热失重仪(TGA)研究了PEG-PET共聚酯的等温降解性能,考察了PEG含量对于聚酯热降解率的影响,并根据PEG的含量和时间计算了影响因子。采用差热扫描量热仪(DSC)研究了PEG-PET嵌段共聚酯的热性能,计算了非等温结晶动力学参数。研究结果表明:PEG-PET改性聚酯热稳定性受氧气影响极大,各嵌段共聚酯样品的按照降解速率可分为2个阶段。在空气氛围条件下,较短时间也会导致嵌段共聚酯的降解。随着PEG含量的增加,嵌段共聚酯的玻璃化转变温度T_(g)、冷结晶峰温T_(c)、结晶熔点T_(m)呈现降低趋势,熔融结晶峰温T_(mc)呈现升高的趋势。随着共聚酯中PEG单体含量的增加,半结晶期t_(1/2)减小,Z _(c)逐渐变大。与冷结晶相比,PEG柔性单体的引入对于熔融结晶的促进作用更加明显。     

Synthesis,characterization, and properties of degradable poly(l‐lactic acid)/poly(butylene terephthalate) copolyesters containing 1,4‐cyclohexanedimethanol

High‐molecular‐weight copolyesters based on poly(butylene terephthalate) as rigid aromatic segments and poly(l‐lactic acid) (PLLA) as degradable aliphatic segments were synthesized via the polycondensation of terephthalic acid, 1,4‐butanediol (BDO), 1,4‐cyclohexanedimethanol (CHDM), and PLLA oligomer. By tailoring the molar ratio of diols (BDO and CHDM), we investigated in detail the effects of the CHDM rigid hexacyclic ring on the synthesis, mechanical properties, thermal stabilities, and degradation behaviors of the copolyesters. With increasing CHDM content, the initial decomposition temperature increased from 282.5 to 322.2°C, and the tensile strength improved by nearly four times, from 5.4 to 19 MPa. When the molar ratio of BDO/CHDM was 95/5, the weight‐average molecular weight of the copolyester was 89,400 g/mol with a polydispersity of 1.96. In addition, hydrolytic degradation results in phosphate buffer solution indicate that the degradation rate of the copolyesters displayed a strong dependency on the temperature and CHDM composition. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

1，4-环己烷二甲醇改性共聚酯的热性能研究

以1,4-环己烷二甲醇(CHDM)部分替代乙二醇(EG)与对苯二甲酸(PTA)共聚合成共聚酯(PETG)。采用DTA,DSC等手段研究了不同CHDM含量及其异构体比例对PETG热性能的影响。结果表明:CHDM的加入对PETG热稳定性影响不大,随CHDM含量的增加,PETG结晶性能降低,玻璃化转变温度逐渐降低。CHDM异构体中反式比例提高时,得到的PETG耐热性能好。     

酯型阳离子染料易染共聚酯纤维的研究 （Ⅰ）共聚酯的合成研究

为了改善ＥＣＤＰ的耐热性，选用耐热性优良的脂肪族聚酯二醇作为第四组分，ＳＩＰＥ为第三组分，采用ＰＴＡ路线进行酯型ＥＣＤＰ合成研究，并利用ＤＳＣ、ＧＰＣ等手段对共聚酯进行性能研究，结果表明：合适的聚合温度为２７５～２８０℃；ＳＩＰＥ使得共聚酯ＤＥＧ生成量增高．熔点降低，低聚体含量升高；加入ＮａＡｃ可以抑制ＤＥＧ生成；加入第四组分，共聚酯Ｔｍ、Ｔｃ、Ｔｇ和－ＣＯＯＨ均有下降．     

支化聚酯的合成及热性能研究

通过直接酯化-缩聚工艺,在聚对苯二甲酸乙二醇酯(PET)聚合的缩聚过程中分别引入第三组分——3-羟甲基丙烷(TMP)、季戊四醇(PER)或双季戊四醇(DPT)合成了一系列不同的支化PET,并采用氢核磁共振波谱仪(1H-NMR)、差示扫描量热仪(DSC)和热重分析(TG)表征了产物的结构和性能。结果表明:与纯PET相比,经TMP、PER或DPT改性后的支化PET的玻璃化转变温度(Tg)均下降,含摩尔分数0.3%DPT改性的支化PET的Tg最低;除TMP1-PET外,各支化PET的冷结晶温度(Tc)都增大;各支化PET的熔点(Tm)也都呈现下降趋势;除PER3-PET外,各支化PET的结晶焓ΔHc都有所下降,而各支化PET的熔融焓ΔHm却变化不大;所得到的各支化PET具有较好的热稳定性能。     

High Tg and tough poly(butylene 2,5-thiophenedicarboxylate-co-1,4-cyclohexanedimethylene 2,5-thiophenedicarboxylate)s: Synthesis and characterization

The purpose of this study was to enhance the glass-transition temperature of poly(butylene 2,5-thiophenedicarboxylate) (PBTF). A series of poly(butylene-co-1,4-cyclohexanedimethylene 2,5-thiophenedicarboxylate)s (PBCTFs) were synthesized from 2,5-thiophenedicarboxylic acid, 1,4-cyclohexanedimethanol (CHDM), and 1,4-butanediol. CHDM can increase the chain rigidity and lead the β relaxation temperature shift to lower temperature. Consequently, PBCTFs showed not only the high glass-transition temperature, but also high elongations at break. PBTF was a crystalline polyester. However, differential scanning calorimetry and wide-angle X-ray diffraction results suggested PBCTFs were amorphous polyesters. Thermogravimetric analysis results indicated the thermal stability of copolyesters was gradually enhanced with increasing the CHDM content. When the CHDM content was 95 mol %, PBCTF95 exhibited high glass-transition temperature (69.2 °C), tensile strength (44.4 MPa), and elongation at break (205%). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48634.     

Copolyesters developed from bio-based 2,5-furandicarboxylic acid: Synthesis,sequence distribution,mechanical, and barrier properties of poly(propylene-co-1,4-cyclohexanedimethylene 2,5-furandicarboxylate)s

A series of poly(propylene-co-1,4-cyclohexanedimethylene 2,5-furandicarboxylate)s (PPCFs) with different compositions were synthesized from bio-based aromatic monomer 2,5-furandicarboxylic acid and 1,3-propanediol (PDO), along with 1,4-cyclohexanedimethylene (CHDM). The chemical structure, composition, and sequence distribution of PPCFs were determined by nuclear magnetic resonance (¹H NMR and ¹³C NMR). Results showed that the compositions of copolyesters depended on the feed molar ratio of PDO and CHDM, and all the obtained PPCFs copolyesters had triad component in a random sequential structure. With the addition of CHDM, the gas barrier properties of poly(propylene 2,5-furandicarboxylate) (PPF) deteriorated. However, when the content of CHDM reached 79%, PPCF79 still showed the CO₂ and O₂ barrier improvement factor of 4.5 and 3.25, respectively, which were better than those of poly(ethylene naphthalate), a well-known polymer with barrier property. Besides, PPCF79 showed good performance on tensile modulus, tensile strength, elongation at break, and the crystallization enthalpy was improved from 3.2 J g⁻¹ for PPF to 30.7 J g⁻¹ for PPCF79. It has the potential to serve as a promising bio-based polymer with excellent comprehensive performance. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47291.     

Thermal property and miscibility of polycarbonate/copolyester blends

Summary The thermal property and the miscibility of polycarbonate (PC)/copolyester blends were investigated. For the study, different copolyesters were synthesized from terephthalic acid (TPA) and various mixtures of ethylene glycol (EG) and cyclohexane dimethanol (CHDM). Various blends of PC and copolyester were prepared by melt mixing and thermal properties of the blends were studied employing differential scanning calorimeter. It was found that the blends of the PC and the copolyesters were partially miscible when the glycol in the copolyester was composed of 10, 20, or 30 mole % CHDM. However, the blends of the PC and the copolyesters were miscible in all proportions when the glycol in the copolyester was composed of 50 or 70 mole % CHDM. Miscibilities of the PC/copolyester blends depending on the composition of the copolyester are discussed based on the thermal properties of the blends.     

聚(对苯二甲酸-1,3-丁二醇酯/对苯二甲酸-1,4-丁二醇酯)/PEG嵌段共聚物的合成及性能研究

用熔融缩聚法合成了一系列聚(对苯二甲酸-1,3-丁二醇酯/对苯二甲酸-1,4-丁二醇酯)/聚乙二醇的嵌段共聚物。用FT-IR,1H-NMR,DSC,TGA,水降解测试等方法表征了材料的结构与性能。FT-IR和1H-NMR分析表明合成得到的共聚物为预期产物;DSC分析显示,共聚聚酯随着1,3-丁二醇在共聚物中比例的增大,熔点(Tm)逐渐降低,由158.24℃下降至104.19℃,玻璃化温度(Tg)逐渐升高,由4.86℃升至24.56℃,合成得到的共聚酯趋向于无定形态;TGA分析表明1,3-丁二醇在共聚酯中比例增大会使聚酯的热稳定性下降,但合成得到的共聚酯依然具有较好的热稳定性,初始分解温度大于310℃,不需要在反应过程中添加热稳定剂;水降解测试结果表明共聚物随1,3-丁二醇比例的增加,降解速率大幅提升。     

Poly(ethylene terephthalate) copolymers that contain 5‐tert‐butylisophthalic acid and 1‐3/1‐4‐cyclohexanedimethanol: Synthesis,characterization, and properties

The effects of incorporating 5‐tert‐butylisophthalic acid (^tBI) and 1‐3/1‐4 cyclohexanedimethanol (CHDM) in the polymer chain of poly(ethylene terephthalate) (PET) on the crystallization behavior and thermal, optical and tensile properties of this polyester (PETGB) were evaluated. These random copolyesters that contained between 0 and 20 mol % of CHDM and between 0 and 10 mol % of ^tBI units were prepared by esterification followed by melt copolycondensation. The compositions and molecular weights of the copolyesters were determined by ¹H‐NMR spectroscopy and viscometry, respectively. The composition of the polyester was consistent with the composition of the feed. The intrinsic viscosities of the copolymers ranged between 0.62 and 0.74 dL/g. The thermal behaviors were investigated over the entire range of copolymer compositions, using DSC under the heating and cooling rate of 20°C/min and TGA. The copolyesters with ^tBI and CHDM of < 20 mol % were crystallizable, whereas the copolyesters with ^tBI and CHDM of ≥ 20 mol % were amorphous. They appeared to be stable up to 395°C. The optical transmissions of the amorphous polyesters were more than 88% in the visible region. The mechanical behavior was investigated by performing a tensile test. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 279–285, 2007     

聚酰胺弹性体增韧聚乳酸改性研究

选用聚酰胺弹性体(聚酰胺和聚氧乙烯的共聚物,PAE)与聚乳酸(PLA)熔融共混进行增韧改性。结果表明,当PAE弹性体含量在20%～30%(质量分数,下同)之间时,共混体系发生脆韧转变,最大冲击强度达到67.6J/m,但拉伸强度和模量大幅度下降;PAE弹性体含量为5%～10%时共混体系的拉伸强度保持率最高,而且断裂伸长率提高近40倍,综合性能较好;虽然扫描电子显微镜照片显示共混体系为两相分离,但是差示扫描量热分析数据均表明,随着PAE弹性体含量的增加,共混体系的玻璃化转变温度和熔点发生相应变化,证明该共混体系为半溶混性,即两相间存在一定的相互作用;热失重分析数据显示,PAE弹性体在一定程度上提高了PLA的热降解温度。