PTT/PBT共混纤维的性能研究

利用聚对苯二甲酸-1,3-丙二酯(PTT)和聚对苯二甲酸丁二酯(PBT)良好的相容性,开发了PTT/ PBT共混纤维。通过对共混纤维的力学、回弹及染色等性能测试发现,PTT组分的存在明显改善了共混纤维的拉伸性能,而共混纤维的强度相对纯组分纤维略差;当PTT质量分数达到50%后,共混纤维的回弹性优于纯PBT纤维,且在相同拉伸倍数下,PTT的存在降低了共混纤维的沸水收缩率;共混纤维在常压下用分散蓝染色的上染率比纯组分纤维高,当PTT/PBT质量比为50/50时,上染率最高。     

PTT/PETG共混物的热性能和结晶行为研究

主要研究了PTT/PETG共混物的热性能和结晶行为。DSC实验表明:PTT/PETG共混物只有一个Tg,说明两者在无定形区相容性好,而且随着PETG组分的增加,Tg增大。PTT/PETG两组分含量接近时,出现2个结晶峰。热失重分析结果表明:两组分相差较大时,随着PETG含量的增加,共混体系的热稳定性提高。通过观察共混物的结晶形态表明:PTT/PETG为80/20时,其球晶尺寸较大。     

聚酯PTT及PTT/PBT共混体系的结晶形态

选取均聚物聚对苯二甲酸丙二醇酯(PTT)及PTT/聚对苯二甲酸丁二醇酯(PBT)共混物为研究对象,以偏光显微镜(POM)和X射线衍射(XRD)为研究手段探讨了均聚物PTT的结晶形态,以及结晶温度、共混物的组成、等温结晶时间等因素对PTT/PBT共混物结晶形态和性能的影响。结果表明,PTT形成环带球晶的条件是155℃,PTT/PBT共混物的结晶尺寸由于PBT的引入而变小,在PTT质量分数小于60%以后就不能产生环带球晶;PTT/PBT共混物结晶时是两个组分各自结晶,并且相互竞争,使其生成环带球晶的关键是结晶组分的结晶速率要和非结晶组分之扩散速率相匹配。     

ECDP/PTT共混物相容性及流变性能研究

研究了易染阳离子染料可染聚酯(ECDP)/聚对苯二甲酸丙二醇酯(PTT)共混物的相容性及其流变性能。结果表明:ECDP/PTT共混物在无定形区相容性良好,在晶区晶相分离;ECDP/PTT共混物在剪切速率为102~105s-1时属于切力变稀流体;纺丝温度245℃时,ECDP/PTT共混物具有良好的可纺性,ECDP/PTT质量比为60/40时,所得纤维断裂强度最低。     

PTMEG共混改性PBT纤维的制备及其性能研究

以聚对苯二甲酸丁二醇酯-聚四亚甲基醚二醇(PBT-PTMEG)为改性剂,与聚对苯二甲酸丁二醇酯(PBT)进行共混纺丝,通过控制PBT-PTMEG添加量制备不同PTMEG含量的PTMEG/PBT共混纤维,探讨了PTMEG含量对纤维柔软性及其他性能的影响。结果表明:在共混纺丝过程中,PTMEG作为改性组分与PBT相容性良好,PTMEG质量分数为6%时可纺性好,继续增加至8%时可纺性变差;随着PTMEG含量的增加,PTMEG/PBT共混纤维的初始模量显著降低,断裂强度略有降低,断裂伸长率、断裂比功均逐渐提高,吸湿性及染色性能也得到改善;当PTMEG质量分数为6%、拉伸倍数为2.8时,PTMEG/PBT共混纤维的断裂比功最高达0.98 cN/dtex,初始模量也较低为21.8 cN/dtex,纤维的柔软性得到了明显提升,综合性能最好。     

PET/PBT反应性共混纺丝初生纤维的结构性能研究

通过反应性共混纺丝的方法制备了一系列PET /PBT初生纤维,并对其结构和性能进行了研究。DSC结果表明:随着共混物在螺杆中停留时间的增加,冷结晶温度增加而熔融结晶温度和熔点下降,结晶行为的差异可能与嵌段的序列长度随酯交换进行而不断减小有关。 WAXD及SEM的分析还表明:PET /PBT体系在无定形区是相容的,在晶区却是晶相分离的,而非共晶结构。并在实验基础上,对PET/PBT共混体系的可纺性进行了初步探讨。     

PET/PBT共混体系的相容性及结晶行为研究

利用 DSC和光学解偏振仪对不同配比的 PET/PBT共混体系的相容性及结晶行为进行了研究。结果表明 ,PET/PBT共混体系在非晶区是相容的 ,在晶区是相分离的 ;PBT的加入 ,对共混体系的结晶性能有显著提高 ,但由于酯交换反应的存在 ,使得共混体系的结晶性能表现出一定程度的不稳定性。     

乙烯-醋酸乙烯酯共聚物/高密度聚乙烯的性能研究

讨论了不同高密度聚乙烯(HDPE)含量的乙烯-醋酸乙烯酯共聚物(EVA)/HDPE共混物的流变性能、热性能、相容性,以及共混纤维的可纺性、力学性能。实验结果表明:随着HDPE含量的增加,共混物的流动性变差;共混物的晶区是部分相容的。当共混物中HDPE的百分含量为15%时,共混物的可纺性及共混纤维的力学性能最佳;随着拉伸倍数的增加,共混纤维断裂强度增大、断裂伸长率降低。     

PET/PTT共混体系的相容特性及力学性能研究

通过熔融共混法制备了聚对苯二甲酸乙二醇酯(PET)与聚对苯二甲酸醇酯(PTT)的共混物,采用差示扫描量热仪、动态热机械分析仪、万能电子试验机等对共混体系的热性能、动态力学性能及拉伸性能进行了测试。测得PET/PTT共混体系只有1个玻璃化转变温度(Tg)和损耗峰,表明在非晶区完全相容,其中纯PET的Tg为84℃,纯PTT的Tg低于50℃; 而双重熔融峰及热结晶峰宽化现象的出现表明,共混体系在晶区是部分相容,各组分倾向于分别进行有序化排列、单独结晶,其中纯PET的熔点为256℃,纯PTT的熔点为229 ℃;共混体系的拉伸模量和拉伸强度随PTT含量的增加呈上升趋势;但当共混比例接近时体系的拉伸模量和拉伸强度有所下降,共混比为5/5时的拉伸模量和拉伸强度分别低达1098MPa和51MPa。     

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。     

Effects of polytrimethylene terephthalate on crystallization and melting behavior of beta-polypropylene in the blends

It has been observed that the formation of β-crystal is suppressed when β-polypropylene (β-PP) is blended with crystalline polymers, but the reason is still uncertain. In this study, we investigated the influence of the crystallization conditions of polytrimethylene terephthalate (PTT), such as melt crystallization, cold crystallization, isothermal crystallization temperature, and crystallization time on the β-nucleation behavior of PP phase in the β-PP/PTT blends. The results showed that the β-crystal content of PP phase in the blends decreases with increasing of PTT content. Cold crystallization of PTT would mainly induce the formation of α-crystal in PP component, whereas melt crystallization would induce the formation of β-crystal PP in their blends. The degree of crystallinity of PTT increases by improving the crystallization temperature or extending the time of crystallization, which leads to the production of more α-crystal in PP component. This means that the second component could inhibit the formation of β-crystal in PP.     

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     

PMMA/PET共混体系可纺性及纤维的结构与性能

研究了PMMA/PET共混纤维的可纺性和拉伸性,并测定了拉伸丝的力学性能、取向和结晶结构。结果表明,PMMA的加入可以延迟PET的成形,减小纤维的取向,提高PMMA/PET卷绕丝的断裂伸长,从而提高纤维的后拉伸倍数,提高纤维的生产效率;PMMA的加入量在5％以下时,不影响纤维的可纺性;PMMA/PET共混纤维拉伸丝的强度和断裂伸长可达到常规PET纤维的要求;扫描电镜照片显示,PMMA以棒状形式分散在PET基体中,分散直径为1μm左右。     

聚酯类聚合物的共混及复合研究(续二)

<正>2复合由于2种组分不同的收缩性,复合纤维具有自卷曲性能,而PET/PTT的热收缩差异,正是制备卷曲纤维所需要的,从而使它有着良好的应用价值。由于弹性纤维氨纶使用时需包覆其他纤维,而且不     

碳纤维增强PBT/ABS-g-MAH复合材料的力学性能和流变行为

利用扫描电子显微镜、电子万能试验机、冲击试验机、旋转流变仪和差示扫描量热仪分别研究了聚对苯二甲酸丁二醇酯（PBT）/马来酸酐接枝丙烯腈丁二烯苯乙烯共聚物（ABS-g-MAH）/短切碳纤维（SCF）复合材料的相形态、力学性能、流变和结晶行为。结果表明,复合材料断面上纤维的分布较为均匀,SCF与PBT之间有较好的界面结合性能;当SCF含量为5 %~10 ％时,复合材料的力学性能得到明显提高;随着SCF含量的增加,复合材料熔体的复数黏度呈现先降低后升高的趋势;在体系中添加适量的SCF可以起到成核剂的作用,由于结晶变得相对容易,从而使结晶温度升高,然而过量的SCF会在一定范围内阻碍PBT的结晶。     

Crystallization, hydrolytic degradation, and mechanical properties of poly (trimethylene terephthalate)/poly(lactic acid) blends

Crystallization, melting, hydrolytic degradation, and mechanical properties of poly(trimentylene terephthalate)/poly(lactic acid) (PTT/PLA) blends have been investigated. The blends show a single and composition-dependent glass-transition temperature (T _g) over the entire composition range, implying that these blends are fully miscible in the amorphous state. The observed T _g is found to increase with increasing PLA content and fitted well with the Gordon–Taylor equation, with the fitting parameter k being 0.91. The cold-crystallization peak temperature increases, while the melt-crystallization peak decreases with increasing the PLA content. Both the pure PTT and PTT/PLA blends cannot accomplish the crystallization during the cooling procedure and the recrystallization occurs again on the second heating. Therefore, on the thermogram recorded, there is exothermal peak followed by endothermal peak with a shoulder. However, to pure PLA, no crystallization takes place during cooling from the melt, therefore, no melting endothermic peak is found on the second heating curve. WAXD analysis indicates PLA and PTT components do not co-crystallize and the crystalline phase of the blends is that of their enriched pure component. With increasing PLA content, the hydrolytic degradation of the blend films increases, while both the tensile strength and the elongation at break of the blend films decrease. That is to say, the hydrolytic degradation of the PTT/PLA blends increases with the introduction of PLA at the cost of the decrease of the flexibility of PTT.     

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     

Morphology and mechanical behavior of isotactic polypropylene (iPP)/syndiotactic polypropylene (sPP) blends and fibers

The crystallization morphologies and mechanical behaviors of iPP/sPP blends and the corresponding fibers were investigated in the present work. For all the investigated iPP/sPP blends, the starting crystallization temperature of sPP during cooling process was significantly increased with increasing iPP content. The iPP/sPP blends are strongly immiscible at the conventional melt processing temperatures, in consistence with the literature results. As isothermally crystallized at 130 °C, sPP still keeps melt state, while iPP component is able to crystallize and the spherulites become imperfect accompanied by decreasing of the crystallite size as sPP content increases. The addition of sPP decreases the crystallinity of iPP/sPP blends and fibers. The storage modulus, E′, of the iPP/sPP blends is higher than that of sPP homopolymer in the temperature range from −90 to 100 °C. The iPP/sPP fibers can be prepared favorably by melt-spinning. As sPP content exceeds 70%, the elastic recovery of the iPP/sPP fibers is approximately equal to that of sPP homopolymer fiber. The drawability of the as-spun fiber of iPP/sPP (50/50) is better than that of sPP fiber, which improves the fiber processing performance and enhances the mechanical properties of the final product. The drawn fiber of sPP presents good elastic behavior within the range of 50% deformation, whereas the elastic property of the iPP/sPP (50/50) fiber slightly decreases, but still much better than that of iPP fiber.     

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