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成核剂对PET/PEN共混体系非等温结晶的影响 总被引:1,自引:0,他引:1
采用差示扫描量热法(DSC)研究了三种成核剂苯甲酸钠(SB)、1,3∶2,4-二亚苄基-D-山梨醇(DBS)、碳酸钙(CaCO3)对聚对苯二甲酸乙二醇酯(PET)/聚2,6-萘二甲酸乙二醇酯(PEN)共混体系的非等温结晶动力学的影响。结果表明,在PET/PEN/成核剂共混体系的非等温熔融结晶过程中,随着冷却速率的升高,结晶起始温度、终止温度、结晶峰温度都向低温方向移动,成核剂的加入使得不同速率下PET/PEN的结晶温度明显提高,结晶更为容易,SB、CaCO3、DBS均起到了较好的成核作用。由于次级结晶的存在,采用Ozawa法不能很好地描述PET/PEN/成核剂共混体系的非等温熔融结晶过程;莫志深法能较好地描述体系的非等温熔融结晶过程。 相似文献
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成核剂1,3:2,4-二(亚苄基)-D山梨醇对PET/PEN共混体系结构和结晶形态影响 总被引:1,自引:0,他引:1
利用差示扫描量热仪、X射线衍射仪、正交偏光显微镜研究了成核剂1,3:2,4-二(亚苄基)-D山梨醇(DBS)对聚对苯二甲酸乙二醇酯(PET)/聚2,6-萘二甲酸乙二醇酯(PEN)共混体系的结构及结晶形态的影响。结果表明:成核剂的加入,使PET/PEN共混体系熔融起始温度升高10℃左右,结晶峰形变尖锐,说明加入成核剂后有效促进了PET/PEN共混体系的结晶。实验结果表明:成核剂含量低于1%时,PET/PEN共混体系晶体的球晶完整。成核剂含量大于3%时,PET/PEN/DBS共混体系晶体的球晶碎小。成核剂的加入,能够有效地减小球晶尺寸和降低球晶的完善性. 相似文献
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采用反应熔融共混技术制备了聚对苯二甲酸丁二醇酯(PBT)/线型低密度聚乙烯(LLDPE)共混物。为了改善PBT/LLDPE共混体系的相容性,采用环氧化三元乙丙橡胶(e EPDM)为增容剂。使用X射线衍射(XRD)、示差扫描量热仪(DSC)和热重分析(TG)研究了e EPDM对PBT/LLDPE共混体系熔融-结晶行为和热学性能的影响。结果表明,橡胶的加入对基体PBT的熔融-结晶行为有一定的影响。随着EPDM或e EPDM用量的增加,共混物中PBT的晶型结构保持不变,但结晶程度减弱,且EPDM或e EPDM对PBT结晶的影响比对LLDPE的更为明显。与纯PBT相比,共混体系的熔融-结晶温度和热分解温度均向高温方向移动,且因熔融共混过程中e EPDM与PBT的相互作用导致e EPDM的影响比EPDM的更为明显。 相似文献
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采用差示扫描量热法(DSC)研究了聚对苯二甲酸乙二醇酯/聚对苯二甲酸丁二醇酯(PET/PBT)共混物的非等温结晶行为;研究了冷却速率对PET/PBT滑/石粉(Talc)成/核剂(P250)共混物结晶行为的影响。对其数据分别采用Jeziorny法、Ozawa法和Mo法进行处理。结果表明:PET/PBT共混物在加入滑石粉后相对结晶度(Xc)有所下降,但是结晶速率提高;PET/PBT/Talc体系单独引入成核剂体系效果更优;PET/PBT/Talc/P250体系随降温速率的增大,结晶度下降,结晶速率加快;Jeziorny法和Mo法处理非等温结晶过程比较理想,Ozawa法则具有一定的局限性。 相似文献
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聚对苯二甲酸丁二酯(PBT)因其热变形温度低,在高温湿热环境下时会产生变形,而影响其正常使用。而PBT热变形温度低的根本原因是由于其结晶度较低,因此,选用了三种无毒安全的成核剂和预处理方法来促进PBT结晶,提高其结晶度,从而提高其耐热性。主要研究了三种成核剂对PBT力学性能、热变形温度以及结晶性能的影响,实验结果表明成核剂B(二氧化钛)和成核剂C(苯甲酸钠)复配对PBT耐热性能的提高最有效,而热处理也能显著提高PBT的耐热性,可以得到热变形温度大于150℃的制品,同时,对于通过加入复合成核剂且经过热处理制备的PBT样条进行高温高压蒸煮和耐溶剂实验,结果表明,该样条耐热性和耐溶剂性都很好。 相似文献
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The isothermal crystallization kinetics of virgin, melt‐mixed, and nucleated specimens of polyethylene terephthalate (PET), polypropylene terephthalate (PPT), and polybutylene terephthalate (PBT) were measured. The purpose of the study was to determine the difference in crystallization rate of PPT, which is to be commercially available in the near future, to the extensively studied, commercially important polyalkylene terephthalates PET and PBT. At equivalent supercooling, the crystallization rate of PPT was between that of PET and PBT, with PBT being the fastest crystallizing polymer. Melt‐mixing virgin materials resulted in a substantial increase in the crystallization rate for all three polyalkylene terephthalates. The addition of talc or sodium stearate as a nucleating agent resulted in a further increase in crystallization rate for all three polyesters. Although the addition of talc or sodium stearate to PPT and PET greatly enhanced crystallization rate, these nucleating agent–containing materials still did not crystallize as fast as PBT melt‐mixed in the absence of any intentionally added nucleating agents. Analysis of the crystallization kinetic data using the Avrami equation showed that melt‐mixing and the addition of sodium stearate resulted in an increase in the average Avrami exponent. This result suggested a change in the mechanism of nucleation toward more sporadic nucleation. For the sodium stearate–nucleated materials, the Avrami exponent was found to increase with increasing crystallization temperature, but a precise explanation of this behavior could not be provided without a knowledge of crystallite morphology. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1296–1307, 2000 相似文献
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PBT/PET共混切片结晶性质的研究 总被引:1,自引:0,他引:1
本研究采用JJY-Ⅰ型光学检偏振仪测试不同配比PBT/PET共混切片的等温结晶性质,用电子计算机处理数据,获得了PBT/PET共混切片的等温结晶动力学参数。并采用准等温处理方法,将等温结晶动力学参数用于非等温过程中,得到不同配比PBT/PET共混切片一系列结晶动力学特性参数。从其中的动力学结晶能力G,可判断在同一稳态纺丝条件下,不同配比PBT/PET卷绕丝的相对结晶度大小;采用PEDSC-Ⅱ型测试了不同共混配比的PBT/PET切片的非等温结晶性质,其结果和用JJY-Ⅰ型测试结果一致;本研究还探讨了添加剂(成核剂)对PBT/PET共混切片结晶性质的影响。 相似文献
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Jie‐Hui Fu Xiao‐Dong Chen Qun‐Jie Xu Rui‐Yuan Wang Xi‐Jun Wang 《Polymer Composites》2016,37(4):1167-1172
In this article, the Surlyn® 8920 and AX 8900 were mixed as hybrid nucleating agents for glass fiber (GF)‐reinforced polyethylene terephthalate (PET)/polybutylene terephthalate (PBT) alloy. The crystallization behaviors on GF‐reinforced PET/PBT alloy with compound nucleating agents of Surlyn® 8920 and AX 8900 were studied by differential scanning calorimeter. The Jeziorny method, Mo method, and Kissinger method were used for studying the non‐isothermal crystallization process of the composite alloys. While single AX 8900 cannot further improve the crystallization properties of the alloy and reduced the crystallization rate, the introduction of Surlyn® 8920 can effectively ameliorate the condition. The results demonstrated the hybrid nucleating agents of Surlyn® 8920 and AX 8900 not only can accelerate crystal growth, but also can significantly reduce the energy barrier, and it has a good effect in the alloy to the nucleation. POLYM. COMPOS. 37:1167–1172, 2016. © 2014 Society of Plastics Engineers 相似文献
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系统地研究了四种成核剂:N-A、液晶VectraA950、滑石粉(Talc)、乙撑双硬脂酰胺(EBS)对聚对苯二甲酸乙二醇酯(PET)的结晶行为的影响。采用差式扫描量热仪(DSC)研究了PET/成核剂复合体系的非等温结晶行为,通过小角激光散射(Sals)、X衍射(XRD)对PET/成核剂复合体系的晶体尺寸和晶体结构进行了研究。结果表明,引入成核剂后,PET的结晶行为有较大改善,结晶峰向高温方向移动,且变尖锐,结晶尺寸变小,结晶度提高,除EBS外,均使PET结晶诱导时间减少。在这四种成核剂中,离子聚合物成核剂N-A成核效果最好。 相似文献
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研究了酰胺类β晶型成核剂对无规共聚聚丙烯(PP R)非等温结晶动力学的影响。结果表明,β成核剂提高了PP R的结晶峰温。在相同的冷却速率下,β成核剂改性PP R体系的Zc比纯PP R小,半结晶时间t1/2比纯PP R长;达到相同结晶度时,β成核剂改性PP R体系所需的冷却速率大于纯PP R,这说明β成核剂的加入降低了PP R的结晶速率。莫法可以很好地表征PP R及β成核剂改性PP R体系的非等温结晶行为。 相似文献
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成核剂对PET非等温结晶动力学的影响 总被引:7,自引:1,他引:6
利用差示扫描量热仪(DSC)研究了滑石粉、苯甲酸钠和离子聚合物Surlyn对聚对苯二甲酸乙二醇酯(PET)非等温结晶行为的影响,并用Ozawa模型计算了非等温结晶动力学参数。结果表明:三种成核剂均是PET的良成核剂,其中苯甲酸钠的成核效果最为显著。与纯PET相比,三种成核剂的加入均使PET的结晶峰温度Tmc向高温偏移,过冷度(Tm-Tmc)明显降低,结晶速率常数K明显增大。纯PET和PET/成核剂共混体系的Ozawa指数n值介于1-4之间,均不为整数,且PET/成核剂共混体系的Ozawa指数n值小于纯PET的n值。 相似文献
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Joon-Yong Park Moo Hyun Kwon Young Sil Lee O Ok Park 《Korean Journal of Chemical Engineering》2000,17(3):262-265
The effects of nucleating agent on nonisothermal crystallization were examined for syndiotactic polystyrene (SPS) using Differential
Scanning Calorimetry (DSC). The crystallization peak temperature Tc, the crystallization rate parameter (CRP), the enthalpy of crystallization and melting, and the recrystallization behavior
were compared between organic (DMBS, 1,3,2,4-dis-5-(3,4-dimethyl benzylidene) sorbitol) and inorganic (talc) nucleating agents.
Both of the nucleation agents promoted the crystallization rate of SPS until some critical concentration of about 3,000 ppm.
DMBS worked more effectively as a nucleating agent than talc, although the Tc showed lower level in SPS/DMBS than SPS/talc. 相似文献
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采用DSC研究了聚丙烯(PP)和三种有机成核剂成核的PP在不同的降温速率下的非等温结晶动力学。用Avrami对DSC的测试结果进行了分析。结果表明,三种有机透明成核剂能显著提高PP的结晶温度和结晶速率。可以用修正Avrami方程的Jeziorny法来处理三种有机成核剂成核PP的非结晶等温结晶行为,处理结果表明:三种有机成核透明成核剂成核PP的半结晶时间减少,结晶动力学常数(Zc)增加,结晶速率增加;松香型成核剂能最快提高PP的结晶速率;同一降温速率下,三种有机成核透明剂成核PP的n值较纯PP减少,结晶成核方式发生了改变。 相似文献