PBT/PET/GF/滑石粉的非等温结晶行为

采用差示扫描量热仪(DSC)考察了PBT/PET/GF/滑石粉的非等温结晶过程,研究了降温速率对PBT/PET/GF/滑石粉的结晶过程的影响,分别采用Jeziorny方程、Ozawa方程和Mo方程对PBT/PET/GF/滑石粉的非等温结晶动力学数据进行分析处理,计算PBT/PET/GF/滑石粉非等温结晶的动力学参数和非等温结晶活化能。结果表明:对于PBT/PET/GF/滑石粉,用Mo法处理得到的结果更理想,Jeziorny法有一定的局限性,Ozawa法不适用;PBT/PET/GF/滑石粉的非等温结晶活化能为-317.67 kJ/mol。     

PA6/硅灰石纤维复合材料的非等温结晶动力学研究

采用差示扫描量热法(DSC)研究了PA6/硅灰石纤维复合材料的非等温结晶行为,分别采用Jeziorny法、Ozawa法和Mo法对非等温结晶动力学进行了分析,经过计算得到相应的非等温结晶动力学参数。结果表明:复合材料的结晶分为初期结晶阶段和二次结晶阶段,随着降温速率的增大,结晶温度降低,结晶温度范围变大,结晶速率增大。Jeziorny法和Mo法能较好地描述复合材料的非等温结晶过程,而Ozawa法不适合描述该过程。     

PET/PBT共混物非等温结晶行为的研究

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。     

PTT非等温结晶动力学研究

采用差示扫描量热仪对PTT进行非等温结晶研究。利用不同动力学模型对其结晶过程进行处理, 并将PTT与PET及PBT的非等温结晶过程进行对比。结果表明:Jeziorny方程和Ozawa方程都可以很好的 描述PTT,PET,PBT的非等温结晶过程;采用结合Avrami方程和Ozawa方程的处理方法,得到了3种聚酯的 结晶速率的大小关系:PBT>PTT>PET。通过计算Ziabicki结晶能力参数,得到3种聚酯的结晶能力的顺序 为:PBT>PTT>PET。     

热塑性动态硫化BIIR/PP TPV中PP的结晶行为及非等温结晶动力学研究

使用示差扫描量热仪(DSC)研究了BIIR/PP TPV中PP的非等温结晶动力学.通过Jeziorny法、Ozawa法以及Mo法分析了纯PP和BIIR/PP TPV中PP的非等温结晶动力学.通过Kissinger法计算了非等温结晶活化能.结果表明,Jeziorny法和Mo法可以很好的表征纯PP和BIIR/PP TPV中...     

β成核剂改性均聚PP非等温结晶动力学研究

用差示扫描量热法对均聚聚丙烯(PPH)和添加β成核剂的PPH(β-PPH)的非等温结晶过程进行了研究,并分别用修正Avrami方程的Jeziorny法、Ozawa法及莫志森法处理非等温结晶过程。结果表明:Jeziorny法和莫志森法均能很好描述PPH和β-PPH的非等温结晶动力学;而采用Ozawa法分析PPH和β-PPH的非等温结晶过程效果不理想。     

尼龙6/高岭土复合材料的非等温结晶行为研究

用差示扫描量热法研究了尼龙6/高岭土复合材料的熔融结晶行为,并用Jeziorny法、Ozawa法、Mo法对复合材料的非等温结晶动力学进行研究。结果表明,3种高岭土的加入均使复合体系的熔融峰变窄,熔点增加;结晶峰温和结晶起始温度提高,结晶速率增大;高岭土填料起到异相成核作用;Jeziorny法、Mo法均适合分析尼龙6及复合体系的非等温结晶动力学过程,而Ozawa法不适合。     

PA6/HBPA共混物的非等温结晶动力学研究

采用熔融共混法制备了聚酰胺6/含磷超支化聚酰胺(PA6/HBPA)共混物。通过差示扫描量热法(DSC)考察了该共混物的非等温结晶行为,并利用改进Avrami方程的Jeziorny法、Ozawa法和Mo法对DSC测试结果进行了非等温结晶动力学分析。结果表明:当HBPA用量为2%时,PA6基体的结晶度和结晶速率均有所提高,而进一步增大HBPA用量则会对PA6的结晶产生阻碍作用,致使结晶速率降低。另外,Ozawa法不适于描述PA6/HBPA共混物的非等温结晶动力学,Jeziorny法则仅适用于PA6/HBPA的结晶初期和中期,而Mo法很好地描述了PA6/HBPA共混物的非等温结晶行为,因而可用于PA6/HBPA的非等温结晶动力学分析。     

POM /TPU共混物非等温结晶动力学研究

采用差示扫描量热法(DSC}研究了不同冷却速率下聚甲醛( POM)以及POM/热塑性聚氨酷弹性体(TPU)共混物的非等温结晶过程,分别采用Jeziorny法、Ozawa法和Mo法进行处理。结果表明:随着冷却速率的增大,POM及其共混物的结晶峰都变宽,结晶峰值温度(Tc)都降低;在相同冷却速率下,POM /TPU共混物的Tc。较纯POM有所提高;Jeziorny法和Mo法处理非等温结晶过程比较理想,而由于次级结晶的存在Ozawa法并不适用;Jeziorny法和Mo法处理所得的数据表明,TPU的加人能够提高POM的结晶速率,减小半结晶时间(t1/2),并且导致POM的结晶成核和生长发生了改变。     

PA 6非等温结晶动力学研究

用差示扫描量热法研究了聚酰胺(PA)6的非等温结晶动力学,并分别用Ozawa法、Jeziorny法和莫志深方程法处理PA 6的非等温结晶行为。结果表明:Ozawa法和Jeziorny法均不能很好地描述PA 6非等温结晶过程;莫志深方程结合Avrami和Ozawa方程,可很好地描述PA 6非等温结晶过程;PA 6的结晶受温度的影响较大,一旦成核,结晶可在短时间内发展得比较完善。     

PET/纳米硫酸钡复合材料性能研究

通过熔融共混法制备聚对苯二甲酸乙二酯(PET)/纳米BaSO4复合材料,研究了纳米BaSO4对PET结晶行为、力学性能及热性能的影响。结果表明,纳米BaSO4在PET基体中起到了成核剂的作用,明显提高了基体树脂的结晶温度和结晶速率,并使材料的DSC曲线发生了显著变化;纳米BaSO4对PET有明显的增强作用,当其质量分数为2%时,PET/纳米BaSO4复合材料的力学性能最优,对比纯PET试样,其拉伸强度和弯曲强度分别提高了16%和18.6%,拉伸弹性模量和弯曲弹性模量分别提高了32%和14%,缺口冲击强度稍有下降;纳米BaSO4也可提高PET的热变形温度。     

PET/滑石粉复合材料结晶性能、热性能和力学性能研究

采用差示扫描量热仪、热重分析仪等研究了滑石粉作为成核剂对聚对苯二甲酸乙二醇酯（PET）结晶性能、热性能以及力学性能的影响。结果表明,滑石粉的添加量为0.5 %（质量分数,下同）时,可有效改善PET的结晶性能,结晶温度（Tc）比经历相同热历程的PET空白试样提高11.36 ℃,且结晶完善程度随降温速率的减小而提高;非等温结晶动力学研究发现,Jeziorny法和莫志深法更符合复合材料的非等温结晶过程,而二次结晶的存在使Ozawa法并不适用;由于滑石粉与基体树脂相容性好并可均匀分散,从而很好地保持了原树脂的热性能,且所得复合材料的力学性能均有所提高,其中拉伸性能提高12 %。     

Non-isothermal crystallization kinetics of poly (lactic acid)/modified carbon black composite

A novel method was employed to modify the surface of carbon black (CB) by an organic small molecule in a Haake Rheomix mixer. Jeziorny equation, the Ozawa model and Mo equation were employed to describe the non-isothermal crystallization process of poly (lactic acid) (PLA), PLA/CB and PLA/modified carbon black (MCB) composites. It is found that the Ozawa model fail to describe the non-isothermal crystallization process for PLA and its composites, while Jeziorny equation and Mo’s theory provide a good fitting. The comparison of crystallization kinetics between PLA/MCB and PLA through Lauritzen–Hoffman model indicates that there appears a transition from regimes II to III in PLA and PLA/MCB. The fold surface free energy σ _e of PLA/MCB composite is higher than that of neat PLA, implying that the existence of nucleating agent is unfavorable for the regular folding of the molecule chain.     

纳米CaCO3对FEP非等温结晶动力学的影响

采用熔融共混法制备了聚全氟乙丙烯（FEP）/纳米碳酸钙（nano-CaCO3）复合材料,利用差示扫描量热法研究了FEP及其复合材料的非等温结晶行为,并通过Avrami方程修正的Jeziorny法、Ozawa法以及Mo法对其非等温结晶动力学进行了处理分析。结果表明,Jeziorny法及Mo法均适用于处理FEP和FEP/nano-CaCO3的非等温结晶过程,但Ozawa法不合适;在同一降温速率下,FEP/nano-CaCO3复合材料的初始结晶温度、最大结晶温度均比相应的纯FEP高,且半结晶时间延长,这说明nano-CaCO3对FEP具有一定的诱导和促进成核的作用,但由于FEP/nano-CaCO3复合材料的长链分子结构及大的空间位垒导致FEP的结晶总速率下降。     

Non-isothermal crystallization kinetics of poly(ethylene terephthalate)/mica composites

The non-isothermal crystallization kinetics of pure poly(ethylene terephthalate) (PET), PET/mica and PET/TiO₂-coated mica composites were investigated by differential scanning calorimetry with different theoretical models, including the modified Avrami method, Ozawa method and Mo method. The activation energies of non-isothermal crystallization were calculated by Kissinger method and Flynn–Wall–Ozawa method. The results show that the modified Avrami equation and Ozawa theory fail to describe the non-isothermal crystallization behavior of all composites, while the Mo model fits the experiment data fair well. It is also found that the mica and TiO₂-coated mica could act as heterogeneous nucleating agent and accelerate the crystallization rates of PET, and the effect of TiO₂-coated mica is stronger than that of mica. The result is further reinforced by calculating the effective activation energy of the non-isothermal crystallization process for all composites using the Kissinger method and the Flynn–Wall–Ozawa method.     

Effective method for dispersing SiO2 nanoparticles into polyethylene

The nonisothermal crystallization behavior and kinetics of polytetrafluoroethylene (PTFE) and PTFE/solid glass microsphere (SGM) composites were investigated with differential scanning calorimetry at various cooling rates (?'s). Three methods, namely, the Jeziorny, Ozawa and Mo methods, were used to describe the nonisothermal crystallization process. The results show that the peak temperature, crystallinity (X_c), and crystallization half‐time were strongly dependent on the content of SGMs and ?. The SGMs in the PTFE/SGM composites exhibited a higher nucleation activity. The nonisothermal crystallization kinetics of PTFE and the PTFE/SGM composites was analyzed successfully with the Jeziorny and Mo methods; however, the Ozawa equation was invalid for the nonisothermal crystallization process. The crystallization activation energy determined with the Kissinger equation was remarkably lower when a small amount of SGMs (5%) was added and then gradually increased and finally became slightly lower than that of pure PTFE as the content of SGMs increased up to 25% in the composites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

NONISOTHERMAL CRYSTALLIZATION KINETICS AND MECHANICAL PROPERTIES OF PP/NANO-SiO2 COMPOSITES

The nonisothermal crystallization kinetics of polypropylene (PP)/nano-SiO₂ composites was studied by means of differential scanning calorimetry (DSC). The modified Avrami theories by Jeziorny, Ozawa, and Mo were used to analyze the data of DSC. The results showed that both the Jeziorny and Mo methods could describe this system very well, but the Ozawa analysis failed. The activation energy was evaluated by the Kissinger method. It was found that the crystallization activation energy of PP was higher than that of PP/nano-SiO₂ composites. The determined results of mechanical properties showed that the addition of nano-SiO₂ increased the mechanical properties of the PP. Micrographs of Polarized optical micrograph (POM) further demonstrated that nano-SiO₂ could toughen the PP.