PTT/PE共混体系结晶动力学及结晶形态研究

采用差示扫描量热法(DSC)研究了聚对苯二甲酸丙二醇酯/聚乙烯(PTT/PE)共混体系的非等温结晶动力学,通过热台偏光显微镜(POM)对共混物在等温条件下的结晶形态进行了研究。结果发现:PTT/PE共混体系各样品的结晶峰温度随着冷却速率的提高而下降,而半结晶时间t1/2随着冷却速率的提高而提高;结晶动力学常数Zc随着冷却速率的提高而下降,表明共混体系的结晶速率随着冷却速率的提高而降低;在POM观察的时间范围内各样品的球晶尺寸随着时间的延长而增大,PTT/PE(30/70)共混体系在190℃结晶时,球晶尺寸较大,即球晶生长较快。     

PTT/PE共混体系结品动力学及结晶形态研究

采用差示扫描量热法(DSC)研究了聚对苯二甲酸乙二醇酯/聚乙烯(PTT/PE)共混体系的非等温结晶动力学,通过热台偏光显微镜(POM)对共混物在等温条件下的结晶形态进行了研究.结果发现:PTT/PE共混体系各样品的结晶峰温度随着冷却速率的提高而下降,而半结晶时间t1/2随着冷却速率的提高而提高;结晶动力学常数Zc随着冷却速率的提高而下降,表明共混体系的结晶速率随着冷却速率的提高而降低;在POM观察的时间范围内各样品的球晶尺寸随着时间的延长而增大,PTT/PE(30/70)共混体系在190℃结晶时,球晶尺寸较大,即球晶生长较快.     

二氧化钛含量对PET非等温结晶性能的影响

采用差示扫描量热法研究了不同二氧化钛(Ti O2)含量聚对苯二甲酸乙二醇酯(PET)的非等温冷结晶和熔融结晶性能。结果表明,与纯PET相比,在二氧化钛含量小于2.4%时,消光PET的冷结晶动力学常数Zc基本不变,半结晶时间t1/2略有减小;随着二氧化钛含量的增加,熔融结晶动力学常数Zc逐渐增大、半结晶时间t1/2逐渐减小,结晶速率加快;Avrami指数n先逐渐增大,当二氧化钛含量达到2.4%后又减小。     

PTT/PBT共混体系及可纺性探究

研究了PTT/PBT共混体系的相容性和结晶性能,并对体系的可纺性作了初步探究。结果表明:PTT/PBT共混体系在无定形区具有较好的相容性,但在晶区是晶相分离的。在冷结晶过程中,当PBT含量超过20%时,将促进体系的结晶性能;而在熔融结晶过程中,第二组分的加入抑制了体系的结晶性能,当配比为50/50时,结晶速率相对最低。另外,PTT/PBT共混体系表现出了良好的可纺性,共混纤维的断裂伸长率随着拉伸倍数和体系中PBT含量的增大而减小,强度增大,但稍差于纯组分纤维;当PTT含量达到50%后,共混纤维表现出了明显优于纯PBT纤维的回弹性,而当PTT含量达到70%时,共混纤维的回弹性能已接近纯PTT纤维。     

PTT／PET共混体系结晶行为和形态研究

利用差示扫描量热仪、正交偏光显微镜研究了聚对苯二甲酸丙二醇酯(PTT)、聚对苯二甲酸乙二醇酯(PET)及PTT/PET共混体系(质量比为25∶75)的结晶行为、形态和等温结晶动力学。结果表明,PTT/PET共混物中,少量的PTT部分地起到了成核作用,但在一定程度上阻碍了PET链段规则地进入晶格,影响了结晶速率。偏光显微镜观察到PET、PTT和PTT/PET共混物在120℃下1、20min的溶液滴膜有较清晰的球晶。     

PET/PTT合金非等温结晶行为的研究

采用差示扫描量热仪对熔融共混制备的聚对苯二甲酸乙二醇酯（PET）/聚对苯二甲酸丙二醇酯（PTT）合金的非等温结晶行为进行研究。结果表明,在相同的降温速率时, 随着PTT含量的增加,PET/PTT合金结晶峰温度向低温方向移动,而且当合金中PET与PTT含量接近时,合金样品出现了双重结晶峰;在降温结晶的过程中,随着降温速率的增大,各合金样品结晶峰温度均降低,其结晶峰均宽化;采用Jeziorny法对上述非等温结晶过程进行了分析,分析结果表明,随着降温速率的增大,各合金样品非等温结晶速率常数增加,其Avrami指数在1~5之间,并且逐渐减小。     

成核剂和结晶促进剂对PET/PTT共混聚酯结晶性能的影响

分别采用双螺杆挤出法和转矩流变仪密炼法制备了PET/PTT共混聚酯,通过拉伸试验、冲击试验和DSC分析,研究了PET/PTT共混聚酯共混配比与力学性能的关系以及不同成核剂和不同结晶促进剂对PET/PTT共混聚酯结晶性能的影响。结果表明,当PET/PTT共混配比为75/25(质量比)时,PET/PTT共混聚酯能同时提高刚性和韧性,纳米SiO2成核剂可明显提高PET/PTT共混聚酯的结晶能力,聚醚1000结晶促进剂可显著提高PET/PTT/纳米SiO2共混聚酯的结晶速率。     

POM与POM/TPU共混物非等温结晶动力学的研究

利用差示扫描量热仪对聚甲醛（POM）非等温结晶动力学进行了研究,并考察了热塑性聚氨酯弹性体(TPU)的加入对POM结晶动力学的影响。通过几种理论模型分析了非等温结晶数据。结果表明, Jeziorny法、莫志深法能够成功描述POM及POM/TPU共混体系的非等温结晶过程。POM的Avrami指数n稍大于POM/TPU共混物的。半结晶时间t1/2与动力学速率参数Zc的值表明POM与POM/TPU共混物的结晶速率随冷却速率的增加而增大,但相同冷却速率下POM的结晶速率要快于POM/TPU共混物。由Kissinger法估算的POM与POM/TPU共混物的活化能分别为513.5、390.5 kJ/mol。     

PET/PTT共混纤维的制备及结构性能研究

将聚对苯二甲酸乙二酯(PET)与聚对苯二甲酸丙二醇酯(PTT)共混纺丝制备PET/PTT共混纤维,研究了共混纤维的结构与性能。结果表明,随着PTT含量的增加,PET/PTT共混纤维的晶粒尺寸逐渐增大;PET/PTT共混纤维的断裂强度较PTT纤维大,回弹性较PET纤维好,沸水收缩率较PET纤维大;当PTT质量分数为50%时,共混纤维的结晶度出现最小值,沸水收缩率出现最大值。     

PTT的非等温结晶动力学研究

采用DSC方法对PTT在不同冷却速率下的结晶过程进行了研究,并与PET进行了对比,其结晶动力学用Mandel Kern方法来处理。结果表明,PTF相对于PET更易成核结晶,PTT半结晶时间比PET长,冷却速率对PTT的半结晶时间影响大,并且PTF的非等温结晶动力学曲线的线性较PET好,能够更好的遵循Mandel Kern方法。     

Melting,crystallization behaviors,and nonisothermal crystallization kinetics of PET/PTT/PBT ternary blends

The melting, crystallization behaviors, and nonisothermal crystallization kinetics of the ternary blends composed of poly(ethylene terephthalate), poly(trimethylene terephthalate) (PTT) and poly(buthylene terephthalate) (PBT) were studied with differential scanning calorimeter (DSC). PBT content in all ternary blends was settled invariably to be one‐third, which improved the melt‐crystallization temperature of the ternary blends. All of the blend compositions in amorphous state were miscible as evidenced by a single, composition‐dependent glass transition temperature (T_g) observed in DSC curves. DSC melting thermograms of different blends showed different multiple melting and crystallization peaks because of their various polymer contents. During melt‐crystallization process, three components in blends crystallized simultaneously to form mixed crystals or separated crystals depending upon their content ratio. The Avrami equation modified by Jeziorny and the Ozawa theory were employed to describe the nonisothermal crystallization process of two selected ternary blends. The results spoke that the Avrami equation was successful in describing the nonisothermal crystallization process of the ternary blends. The values of the t_1/2 and the parameters Z_c showed that the crystallization rate of the ternary blends with more poly(ethylene terephthalate) content was faster than that with the lesser one at a given cooling rate. The crystal morphology of the five ternary blends investigated by polarized optical microscopy (POM) showed different size and distortional Maltese crosses or light spots when the PTT or poly(ethylene terephthalate) component varied, suggesting that the more the PTT content, the larger crystallites formed in ternary blends. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Thermal properties and non‐isothermal crystallization behavior of poly(trimethylene terephthalate)/poly(lactic acid) blends

Thermal properties and non‐isothermal melt‐crystallization behavior of poly(trimethylene terephthalate) (PTT)/poly(lactic acid) (PLA) blends were investigated using differential scanning calorimetry and thermogravimetric analysis. The blends exhibit single and composition‐dependent glass transition temperature, cold crystallization temperature (T_cc) and melt crystallization peak temperature (T_mc) over the entire composition range, implying miscibility between the PLA and PTT components. The T_cc values of PTT/PLA blends increase, while the T_mc values decrease with increasing PLA content, suggesting that the cold crystallization and melt crystallization of PTT are retarded by the addition of PLA. The modified Avrami model is satisfactory in describing the non‐isothermal melt crystallization of the blends, whereas the Ozawa method is not applicable to the blends. The estimated Avrami exponent of the PTT/PLA blends ranges from 3.25 to 4.11, implying that the non‐isothermal crystallization follows a spherulitic‐like crystal growth combined with a complicated growth form. The PTT/PLA blends generally exhibit inferior crystallization rate and superior activation energy compared to pure PTT at the same cooling rate. The greater the PLA content in the PTT/PLA blends, the lower the crystallization rate and the higher the activation energy. Moreover, the introduction of PTT into PLA leads to an increase in the thermal stability behavior of the resulting PTT/PLA blends. Copyright © 2011 Society of Chemical Industry     

MPO改性PTT共聚酯熔融结晶行为研究

采用直接酯化熔融缩聚法合成了一系列不同含量的2-甲基-1,3-丙二醇（MPO）改性的共聚酯,并采用差示扫描量热仪（DSC）研究了其熔融结晶行为。结果表明,MPO的加入使聚对苯二甲酸丙二醇酯（PTT）熔点和结晶温度降低,加入摩尔比为20 %的MPO可以使PTT熔点由原来的226.64 ℃降至201.78 ℃,加入摩尔比为10 %的MPO可以使PTT结晶温度由原来的159.01 ℃降至137.50 ℃,同时使半结晶时间(t1/2)增大;随降温速率的提高,各样品的结晶温度向低温方向移动,放热峰由窄变宽,t1/2变小;不同降温速率下,改性共聚酯的结晶速率常数(Zc)比纯PTT的Zc减小。     

PTT/mPE共混物的制备和性能研究

研究了聚对苯二甲酸丙二酯(PTT)/茂金属聚乙烯(mPE)共混体系的流变性能、结晶熔融行为、力学性能以及增容剂对共混物相形态的影响。结果表明：PTT/mPE共混物熔体为假塑性流体,熔体表观黏度随PTT含量的增加而迅速降低,PTT含量高于40％时共混物表观黏度迅速下降,PTT含量越多对温度变化的敏感性越强。PTT和mPE可分别结晶,但PTT组分的结晶峰温度Tpc和结晶熔融峰温度Tm均比纯PTT的明显提高,而mPE组分的Tpc和Tm与纯mPE的相近,mPE可以促进PTT熔体结晶,但已经形成的PTT晶体不影响mPE的结晶,mPE的结晶行为主要发生在mPE微相区内。增容剂马来酸酐接枝乙丙橡胶提高了PTT与mPE间的相容性,共混物的冲击强度随着增容剂的增加而提高,mPE和增容剂共同发挥了增韧作用。     

PTT的等温与非等温结晶动力学研究

采用DSC方法对聚对苯二甲酸丙二酯进行等温与非等温结晶动力学研究,利用不同动力学模型对其结晶过程进行分析.结果表明,在等温结晶过程中,Avrami指数n和半结晶时间随着结晶温度的升高而增大,结晶速率常数K随着结晶温度的升高而减小;在非等温结晶的过程中,结晶动力学常数Zc和相对过冷度△Tc随着降温速率的提高而上升,Avr...     

Melting and crystallization behaviors of compatibilized poly(trimethylene terephthalate)/acrylonitrile–butadiene–styrene blends

The melting and crystallization behaviors of poly(trimethylene terephthalate) (PTT)/acrylonitrile–butadiene–styrene (ABS) blends were investigated with and without epoxy or styrene–butadiene–maleic anhydride copolymer (SBM) as a reactive compatibilizer. The existence of two separate composition-dependent glass-transition temperatures (T_g's) indicated that PTT was partially miscible with ABS over the entire composition range. The melting temperature of the PTT phase in the blends was also composition dependent and shifted to lower temperatures with increasing ABS content. Both the cold crystallization temperature and T_g of the PTT phase moved to higher temperatures in the presence of compatibilizers, which indicated their compatibilization effects on the blends. A crystallization exotherm of the PTT phase was noticed for all of the PTT/ABS blends. The crystallization behaviors were completely different at low and high ABS contents. When ABS was 0–50 wt %, the crystallization process of PTT shifted slightly to higher temperatures as the ABS content was increased. When ABS was 60 wt % or greater, PTT showed fractionated crystallization. The effects of both the epoxy and SBM compatibilizers on the crystallization of PTT were content dependent. At a lower contents of 1–3 wt % epoxy or 1 wt % SBM, the crystallization was retarded, whereas at a higher content of 5 wt %, the crystallization was accelerated. The crystallization kinetics were analyzed with a modified Avrami equation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Structure and properties of bio-based poly(trimethylene terephthalate)/polyamide 56 blends prepared by melt mixing

The extensive use of conventional petroleum-based polymers consumes large amounts of energy and emits a lot of carbon dioxide. Therefore, the development and popularization of bio-based polymer materials are highly significant for ecological reasons. Herein, a series of poly(trimethylene terephthalate)/polyamide 56 (PTT/PA56) blends with different weight ratios were prepared by melt blending of two bio-based polymers, PTT and PA56. The phase structure, miscibility, crystallization and melting behaviors, crystal structure, and mechanical and water absorption properties of PTT/PA56 blend systems were investigated. The results showed that PTT and PA56 were immiscible in the whole range of compositions. The immiscibility of the blend system intensified with the increase of dispersed phase content. As PA56 content increased, tensile strength and elongation at break of samples assumed an increasing trend, whereas impact strength initially remained almost unchanged and then gradually decreased. In contrast, increasing PA56 content gradually increased water absorption of samples. Comprehensive analysis indicated that the best combination of different properties was obtained for the PTT/PA56 blends including 60–80 wt% PA56.     

PBT/PTT合金的非等温结晶行为

采用差示扫描量热法(DSC)研究了聚对苯二甲酸丁二酯(PBT)/聚对苯二甲酸丙二酯(PTT)合金的非等温结晶动力学.随着降温速率的增大,PBT/PTT合金的结晶峰温均降低,结晶峰均加宽.采用Jeziorny法、莫志深法和Flyn-Wall-Ozawa法分析非等温结晶过程,Jeziorny法能够描述PBT/PTT合金的初期结晶过程,对后期结晶存在一定偏差,各PBT/PTT合金的结晶维数变化不大;莫志深和Flyn-Wall-Ozawa法能很好地描述PBT/PTT合金的非等温结晶过程,随PTT含量增加,由Flyn-Wall-Ozawa法求得PBT/PTT合金的活化能呈增加趋势.相对结晶度为0.5,m(PBT)/m(PTT)分别为90∶10,70∶30,50∶50时,PBT/PTT合金的活化能分别为-201.9,-116,0,-66.6 kJ/mol;相对结晶度为0.5时,m(PBT)/m(PTT)为50∶50的合金活化能比PTT(-77.4 kJ/mol)还高.