PET/离聚物共混体系的结晶行为研究

利用WAXD对聚对苯二甲酸乙二酯（PET）与高聚物Surlyn和Aclyn系列组成的共混体系的结晶行为进行了研究。结果表明，离聚物先于PET结晶，两者分别以各自的晶型出现，没有形成混晶、结晶时两相间有相互干扰;在所研究的范围内，PET／离聚物Na盐井混体系结晶度与纯PET的基本相同，PET／离聚物Zn盐井混体系的结晶度大于纯PET的结晶度，且离聚物含量的变化对其共混体系的结晶度的影响不明显。     

离聚物Surlyn 8920对PET/PBT合金结晶性能的影响

采用差示扫描量热仪和扫描电镜研究了离聚物Surlyn 8920对聚对苯二甲酸乙二醇酯(PET)/聚对苯二甲酸丁二醇酯(PBT)合金结晶性能的影响。结果表明,Jeziorny法和Kissinger法可以较好地模拟共混合金的非等温结晶过程。Surlyn 8920在高温下可与PET、PBT发生反应,起到了异相成核的作用。它不但降低了分子链扩散进入晶格的自由能,也提高了体系的结晶速率,PBT的存在则加速了这种效应。当Surlyn 8920的用量逐渐增大时,反应形成的离子簇自聚集能力逐渐减弱,有效的成核中心逐渐饱和,体系的结晶速率不再加快,反而减慢。Surlyn 8920可以弥补PBT,改性带来的缺陷,当其用量为3%时,其成核效果最好。与纯PET/PBT合金相比,体系的半结晶时间缩短,结晶温度升高,结晶焓增大,结晶活化能降低。     

离聚物Surlyn对PTT/PA6共混物相容性的影响

通过扫描电镜(SEM)、差示扫描量热法(DSC)、傅立叶红外光谱(FTIR)研究了离聚物Surlyn对PTT/PA6共混物的相容性及形态结构的影响。PTT和PA6共混体系为热力学不相容体系,在共混物中加入一种离聚物聚甲基乙基丙烯酸锌(Surlyn),以提高共混物的相容性。实验结果表明,在以PTT为主体的PET/PA6简单共混物中,两者的相容性很差。加入离聚体Surlyn后,增加了界面粘接力,使分散相PA6的尺寸减小、分布趋向均匀。随着Surlyn的加入,PTT/PA/Surlyn共混体系的相容性得到了一定的提高。     

离聚物surlyn对PET/PA66共混物性能的影响

摘要：采用傅里叶红外光谱、示差扫描量热法（DSC）考察了离聚物surlyn对PET/PA66共混体系结构、结晶性能的影响;通过低剪切速率下流变性能测试、力学性能测试以及热变形温度测试,考察了离聚物对该体系流变性能、力学性能、耐热性能的影响。实验结果表明：加入离聚物Surlyn增加了界面的粘接力和分子间的链缠结,使共混体系的相容性得到了提高,其中以离聚物Surlyn含量在10%效果较好。     

苯乙烯-丙烯酸钠离聚物与聚乙二醇复合对PET结晶行为的影响

利用差示扫描量热仪(DSC)研究了离聚物苯乙烯-丙烯酸钠(SAA-Na)和聚乙二醇(PEG)复配物对PET结晶性能的影响。结果表明,1%（质量分数）SAA-Na与5%PEG复配能够进一步提高PET的结晶速率,使熔融结晶温度由PET/SAA-Na的212.8℃升高到<     

一种新型复合成核剂对PET结晶性能和摩尔质量的影响

采用双螺杆挤出机,以熔融挤出法制备了含不同结晶成核剂的聚对苯二甲酸乙二醇酯(PET)样品.利用差示扫描昔热法(DSC)、黏度法研究了成核剂对PET结晶行为和摩尔质量的影响,并对比了复合成核剂(苯甲酸钠/酯交换剂A)与常用成核剂苯甲酸钠及乙烯/甲基丙烯酸共聚物的离聚物(Surlyn)对PET结晶行为和摩尔质量的影响.研究结果表明:在成核能力方面,复合成核剂的效果优于苯甲酸钠和Surlyn;同时,复合成核剂的加入还能有效地降低PET摩尔质馈的损失程度,加入复合成核剂的PET摩尔质量明显高于加入苯甲酸钠的PET样品,与加入Surlyn成核剂的PET样品摩尔质量接近.     

Surlyn对PET及其共混体系流变与结晶性能的影响

通过熔融共混法制备了聚对苯二甲酸乙二醇酯 (PET)/聚酰胺6 (PA6)/Surlyn与PET/均苯四甲酸酐 (PMDA)/Surlyn共混材料，研究了Surlyn对共混体系的形貌以及共混体系中PET流变性能与结晶性能的影响。并使用扫描电子显微镜 观察了PET/PA6/Surlyn共混物的低温淬断断面，使用旋转流变仪与差示扫描量热仪研究共混物的流变性能与结晶性能。结果表明，Surlyn可以提高PET/PA6/Surlyn共混体系的熔体强度，促进共混体系中PET的结晶，使PET结晶温度提高10 ℃，过冷度与结晶半高宽显著下降，明显改善PET的流变性能与结晶性能，而对于PMDA扩链后的PET，Surlyn对其结晶性能的影响影响较小；Surlyn可以降低PA6分散相的粒径，提高PET与PA6两相之间的相容性。     

离聚物增容PET/TLCP共混物的研究及应用

研究了聚对苯二甲酸乙二酯(PET)/热致液晶聚合物(TLCP)原位复合共混物的流变行为、相容性、熔体结晶、耐磨性和微观结构.结果表明,TLCP的加入降低了共混物的扭矩,而增容剂离聚物的加入却提高了扭矩;少量TLCP的加入提高了共混物的结晶速率和结晶度,但是离聚物的加入反而降低了其结晶速率和结晶度;TLCP的加入能提高PET的耐磨性,离聚物的加入使PET/TLCP共混物的耐磨性进一步提高,离聚物的质量分数为5%时,PET/TLCP共混物的耐磨性最佳;TLCP在PET中能原位形成微纤结构,离聚物加入使微纤变小,分布更均匀;利用离聚物增容PET/TLCP所制备的工业丝编织成的造纸网,其使用寿命延长了20%,经济效益显著.     

HT／Surlyn／PEG复合成核剂对PET结晶性能的影响

研究了水滑石(HT)/离子键聚合物(Surlyn)/聚乙二醇(PEG)复合成核剂对聚对苯二甲酸乙二醇酯(PET)非等温结晶性能的影响。通过正交实验选择最佳复合成核剂配方。差示扫描量热分析表明,HT/Surlyn/PEG复合成核剂各组分与PET的质量比为0．5/3/3/100时,PET的结晶温度提高,半结晶时间明显减少,说明PET的成核能力提高,结晶能力增强,结晶速率加快；同时,结晶放热焓和熔融吸热焓增加,说明PET的结晶度得到提高。     

成核剂对PET/PEN共混物性能影响及其机理研究

利用差示扫描量热法、X射线衍射和转矩流变测试等手段,研究了成核剂碳酸氢钠、苯甲酸钠和乙烯-甲基丙烯酸离子键聚合物(Surlyn)对聚对苯二甲酸乙二醇酯/聚萘二甲酸乙二醇酯（PET/PEN）共混物结晶性能和力学性能的影响。结果表明,3种成核剂均能显著提高共混物的成核作用,其中,Surlyn和苯甲酸钠能明显提高共混物结晶性能,结晶峰温度提高约20 ℃,结晶速度提升近1倍;3种成核剂中,只有Surlyn在提高结晶性能的同时,还能提高共混物的力学性能;Surlyn是PET/PEN共混物理想的成核剂。     

离聚体对PA1010／PS共混体系相形态及结晶的影响

采用ＳＥＭ,ＤＳＣ和偏光显微镜等方法研究了磺化聚苯乙烯及其锂盐,锌盐和钠盐（ＰＳ－ＮａＳ）;四种离聚体对ＰＡ１０１０／ＰＳ共混体系相形主结晶性能的影响。结果表明,对于ＰＡ１０１０／ＰＳ（８０／２０）共混体系,四种离聚体的增容效果依次按ＰＳ－ｎａＳ〈ＰＳ－ＺｎＳ〈ＰＳ〈ＺｎＳ〈ＰＳ－ＬｉＳ〈ＰＳ－ＨＳ的顺序递增,表明离聚体的离子交联能力越弱,其增容效果越好。四种离聚体中只有ＰＳ－ＺｎＳ对ＰＡ１０１０     

PC/PET/PE-g-MAM共混体系结晶性能的研究

采用PE-g-MAZn,PE-g-MANa离聚物增容PC/PET共混物,使共混体系相容性得到改善,同时由于离聚物自身成核作用的影响,使得PET的结晶性能发生变化。考察了离聚物接枝率及其用量变化对PC/PET/PE-g-MAM共混体系结晶性能及结晶形态的影响。结果表明,锌离聚物共混体系由于离聚物的成核作用较强,增容作用较弱,PET冷结晶温度随接枝率C增加出现一个极大值,晶粒增加,晶形及结晶度变化不大;钠离聚物共混体系由于离聚物增容作用较强,使共混物结晶形态及T_(gc),T_m,T_(mc)等呈现出不同于锌离聚物共混体系的特征。     

Poly(ethylene terephthalate) ionomer based clay nanocomposites produced via melt extrusion

Poly(ethylene terephthalate) ionomer (PETI)/organically-modified montmorillonite clay (OMC) nanocomposites were prepared via melt extrusion. Sulfonated PET containing various incorporations of ionic comonomer and clay modifications were investigated. The random incorporation of ionic functionalities along the PET backbone enhances interactions between the matrix polymer and montmorillonite clay resulting in the creation of polymer-clay nanocomposites exhibiting a predominately exfoliated morphology. The morphology is correlated with mechanical properties and crystallization behavior. It is found that incorporation of clay into the random ionomers leads to increased mechanical properties and slower crystallization rates.     

Poly(styrene‐co‐maleic anhydride) ionomers as nucleating agent on the crystallization behavior of poly(ethylene terephthalate)

Poly(styrene‐co‐maleic anhydride) (SMA) ionomers were synthesized and designed as a new kind of nucleation agent according to the crystallization theory for improving the crystallization of poly(ethylene terephthalate) (PET). The crystallization behavior of PET with the addition of nucleation agents was investigated by differential scanning calorimetry, polarized‐light microscope, and X‐ray diffraction (XRD). Avrami equation and Hoffman–Lauritzen theory are adopted for analyzing isothermal and non‐isothermal crystallization kinetics, respectively. The results show that the addition of 1 wt % SMA ionomers effectively accelerates the crystallization rate and reduces the fold surface free energy of PET at high temperature regions. PLM results also indicated that the crystals impinge on each other, thus decreasing the spherulite size for PET/SMA ionomers samples compared with PET. XRD measurement revealed that the introduction of SMA ionomers does not change the crystal structure but indeed accelerates the crystallinity of PET. The results clearly demonstrate that our synthesized SMA ionomers are an efficient nucleating agent for PET. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41240.     

Crystallization and melting behavior of the crystalline soft segment in a shape‐memory polyurethane ionomer

To illustrate the crystallization properties of soft segments in shape‐memory polyurethane (SMPU) ionomers, a series of SMPU ionomers with various ionic group contents and two kinds of counterions were synthesized with a prepolymerization method. An isothermal crystallization kinetic method was used to analyze the effects of ionic groups within the hard segments on the crystallization of the soft segments in a heating and cooling routine similar to that in a shape‐memory function. The more ionic groups there were within the hard segments, the lower the crystallization rate was of the soft segments. The crystallization mechanism of the SMPU ionomers was quite close to that of a control sample on the basis of similar Avrami exponents; the counterion category also had some influence on the crystallization rate. Meanwhile, the melting behavior after isothermal crystallization reflected the fact that the thermal history of the hard segments had a huge effect on the crystallization mechanism of the soft segments. Especially for the SMPU ionomer quenched from 240°C, the crystallization time dependence of the secondary crystallization was rather significant, but for the SMPU ionomer quenched from 70°C, the primary crystallization of the poly(?‐caprolactone) soft segment was predominant. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

PET离聚物共混体系的结晶与熔融行为研究

利用ＤＳＣ对聚对苯二甲酸乙二酯（ＰＥＴ）与离聚物Ｓｕｒｌｙｎ和Ａｃｌｙｎ系列组成的共混体系的结晶与熔融行为进行了研究．结果表明，离聚物对ＰＥＴ的低温与高温结晶都有十分明显的促进作用，离聚物Ｎａ盐比离聚物Ｚｎ盐对ＰＥＴ的结晶加速作用显著。共混体系的熔融热焓随离聚物Ｎａ盐含量的增加有所降低，随Ｚｎ盐含量的增加稍有提高，两者的熔点及熔限与熔融热焓的变化规律一致．     

Influence of ionic groups on the crystallization and melting behavior of segmented polyurethane ionomers

The isothermal crystallization kinetics and melting behavior of the soft segment in polyurethane (PU) ionomer/nonionomer based on PCL‐4000 (poly(ε‐caprolactone)) were investigated using polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). In general, the presence of ionic groups in PU ionomers can promote the formation of a more stable crystalline structure and lower the equilibrium melting temperature of the crystallizable phase. Comparison between the crystallization characteristics of PU nonionomers and ionomers suggests that the Coulombic Forces between ionic groups within hard segment can increase the crystallization rate and decrease the crystal size of soft segment when the total molecular weight (M_w) of PU ionomer is higher than ～71,000. On the other hand, the opposite effect of ionic groups on the crystallization rate is observed in PU ionomers with M_w below ～20,000. The DSC thermograms illustrate that the ionic groups can significantly enhance the microphase separation in PU ionomers with higher M_w values. By the control and manipulation of crystallization and microstructure formation in PU ionomer, it is possible to achieve shape memory PUs with superior physical property. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4603–4613, 2006     

成核剂对PET非等温结晶动力学的影响

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。     

The crystallization and formation of cluster of ethylene ionomer during physical aging

The effect of the physical aging of ethylene ionomers was studied for the samples with the acid content of 5.4 mol%, and the degree of neutralization, 0%, 60% Na, 60% Zn, and 90% Zn. The information about the crystal and the cluster part of the physically aged ionomers was obtained by differential scanning calorimetry and by dynamic viscoelastic measurements, respectively. The degree of crystallinity and the dynamic modulus for the ionomers of the degree of neutralization 0%, 60% Na and 60% Zn increased gradually with the aging time; on the other hand, the crystallinity of 90% Zn remained constant and the modulus at 100°C increased to a certain value up to a period of 100 h, but thereafter the crystallinity increased remarkably and the modulus remained. These facts indicate that the crystallization of neutralized ethylene ionomer starts after clustering and the clustering would finish at early stage of the physical aging for intermediately neutralized ethylene ionomer. The physical aging effect of the ethylene ionomers was, thus, found to be important to material design.