PET/PEN共混体系的研究进展

主要综述了PET/PEN共混体系的研究进展,重点讨论了PET/PEN共混体系的相容性、酯交换反应、热性能以及结晶性能,并对其在国内外应用前景做了展望。     

聚芳醚腈合金的制备及性能研究

将2类聚芳醚腈（PEN）共聚物PEN（HQ／RS）和PEN（HQ／PP）,按不同质量比通过熔融共混制备PEN合金材料,测试其相容性、力学性能和热性能,发现聚合物合金在PEN（HQ／RS）质量分数分别为20％和80％时相容性良好,PEN（HQ／RS）的加入改善了PEN（HQ／PP）的加工性能,实验中不同质量比的合金均具有优良的力学性能和热性能。     

PET-PEN共聚酯对PET/PEN共混物的增容作用及其机理

使用聚对苯二甲酸乙二酯(PET)-聚萘二甲酸乙二酯(PEN)无规共聚酯作增容剂,通过双螺杆挤出机熔融共混,制备了不同PET-PEN共聚酯用量的PET/PEN共混物,采用差示扫描量热分析、热重分析、热变形温度测试以及力学实验等方法,研究了该共混物的相容性及其它性能。结果表明,PET-PEN共聚酯对PET/PEN共混物具有明显的增容作用,能有效提高PET/PEN共混物的热稳定性,其用量越高,热稳定性提高越明显,当PET-PEN共聚酯用量为15质量份时,起始失重温度提高了20.3℃。PET-PEN共聚酯增容剂能提高PET/PEN共混物的维卡软化温度、拉伸和弯曲性能以及冲击性能,当PET-PEN共聚酯用量为5质量份时,增容改性的综合效果最好。     

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

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.     

微波辐照对PET／PEN共混物非等温热降解行为的影响

用热失重分析法（TGA）对微波辐照不同时间的PET／PEN共混体系的热降解行为进行了比较分析，用图解微分法和差减微分法计算了降解反应表观活化能（E），频率因子（lnA）和反应级数（n）等降解反应动力学参数，并讨论了微波辐照对PET／PEN共混物热降解行为的影响及其机理。结果表明：微波辐照使PET／PEN共混物的降解反应活化能降低了约23-74kJ／mol，起始降解温度降低了4．16～13．08℃，失重速率加快了0．06～0．27％／℃，从而促进PET／PEN共混物的降解，降解动力学参数（n）的值从0．83增大到了1．86，降解反应的机理由分解控制转为扩散控制。     

啤酒瓶用共缩聚PET/PEN的研究

采用对苯二甲酸二甲酯(DMT)与2，6-萘二甲酸二甲酯(DMN)合成了聚对苯二甲酸二乙酯(PET)和聚2，6-萘二甲酸二乙酯(PEN)共缩聚物，研究了PEN用量对共缩聚PET／PEN热性能的影响，并研究了采用PET／PEN制成的啤酒瓶的物理性能、气体阻隔性能和贮藏性。结果表明：PET／PEN的性能与普通聚酯切片的相近，PEN质量分数为30％的PET／PEN制成的啤酒瓶可耐95℃高温，对O2、CO2气体的阻隔性比普通PET瓶提高6倍。     

PET/PEN/NCL纳米啤酒瓶的研制

用对苯二甲酸二甲酯、2,6-萘二甲酸二甲酯两种单体与乙二醇进行酯交换反应制备了(对苯二甲酸乙二N／2,6-萘二甲酸乙二酯)共聚物(PET／PEN),讨论了纳米累托石(NCL)和PEN不同含量对PET／PEN／NCL纳米复合材料性能的影响。结果表明,PET／PEN／NCL纳米复合材料的合成工艺与普通PET的合成工艺相近;当PEN质量分数为6％、NCL质量分数为3％时制得的PET／PEN／NCL纳米啤酒瓶可耐105℃高温,对O2、CO2的阻隔性比PET瓶提高5—6倍。     

PET/PEN瓶注拉吹成型工艺研究

利用Moldflow软件模拟分析了一模两腔PET/PEN瓶坯的注射成型过程,预测塑件成型过程中可能出现的缺陷,优化冷却水道直径、布局和浇注系统尺寸,提出优化的注射成型方案,然后利用注塑机和PET/PEN瓶坯模具注射成型高质量的瓶坯,再利用吹瓶机等设备拉伸-吹塑成型PET/PEN瓶,这样可确保成型瓶子的厚度均匀分布,以生产合格的PET/PEN瓶.     

PET/PEN共聚物的中空吹塑研究

为兼顾聚对苯二甲酸二乙酯(PET)的经济性和聚2，6-萘二甲酸二乙酯(PEN)的耐热性及阻隔性，制成了一种PET／PEN共聚物，研究了PEN用量对PET／PEN共聚物热性能的影响以及含水量对加工性能的影响，探讨了利用现有加工PET的设备、两步法注射拉伸吹塑工艺生产耐热和阻隔性PET／PEN共聚物制品的可行性。结果表明，为了得到理想的制品外观和性能，需要对挤出螺杆、加工工艺参数、型坯设计和拉伸比进行改进。     

成核剂对PET/PEN共混体系非等温结晶的影响

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。     

PET/PEN扩链反应共混的研究Ⅳ.等温结晶动力学

用差示扫描量热法 (DSC)研究了热历史对 PET/PEN反应性共混物的熔体结晶行为的影响 ,并进行了等温结晶动力学的测定。结果表明 ,由于加热过程中酯交换反应的影响 ,而导致共聚酯序列结构的变化 ,致使熔体结晶行为对热历史极其敏感 ,其结晶动力学参数的变化也与之密切相关。     

Preparation and thermal properties of novel phthalonitrile oligomer containing biphenyl ethernitrile/bisphthalonitrile blends

A kind of novel n = 2 phthalonitrile oligomer containing biphenyl ethernitrile (2PEN‐BPh) had been firstly synthesized from 2,6‐dichlorobenzonitrile, 4,4′‐biphenol and 4‐nitrophthalonitrile via solution reaction, and the 2PEN‐BPh was characterized by FTIR, ¹H‐NMR spectra which exhibited that cyano groups and ethernitrile linkages existed in the backbone of 2PEN‐BPh. The 2PEN‐BPh oligomer was blended with bisphthalonitrile monomer, the curing reaction behaviors of the blends were studied by FTIR, DSC, and rheological analysis. The thermal and thermo‐oxidative stabilities of the 2PEN‐BPh/BPh polymers were investigated by TGA, and the results showed that the completely cured polymers could achieve char yields up to 78% at 800°C in nitrogen, above 11% at 800°C in air. The whole research indicated that the 2PEN‐BPh/BPh blends could efficiently improve the processability of BPh monomer without scarifying other desirable high temperature properties. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

PEN/PA6共混体系的结晶形态与性能研究

以聚酰胺6(PA6)作为第二组分对聚芳醚腈（PEN）进行了改性,通过熔融共混制备了PEN/ PA6共混体系。用扫描电镜、差示扫描量热分析仪、X-射线衍射等方法对共混体系的形态结构和结晶行为进行了研究;用同步分析仪、万能电子试验机对共混材料的耐热性能和力学性能进行了研究。结果表明,PEN与PA6两者具有较好的相容性,随着PA6含量的增加共混体系中PA6的结晶能力逐渐提高,同时由于PA6的加入使得共混体系的加工性能较纯PEN有所改善,共混体系的拉伸强度较纯PEN提高了34 %。     

Morphology,thermal and mechanical properties of glass fiber‐reinforced crosslinkable poly(arylene ether nitrile)

Crosslinkable poly(arylene ether nitrile)/glass fiber (PEN/GF) composites with high thermal stabilities and mechanical properties were prepared by a economically and environmentally viable method of melt extrusion and injection molding. The feasibility of using PEN/GF composites was investigated by evaluating its morphological, rheological, thermal, and mechanical properties. The morphology shows a good dispersion and strong interfacial interaction between PEN and GF. Thermal studies reveal that the thermal stabilities of PEN/GF are improved significantly with increase of GF content. Mechanical investigation manifested that GFs have strengthening effect (increase in flexural, tensile, and impact strength) on the mechanical performance of PEN composites. Most importantly, crosslinking reaction of PEN/GF composites can further improve their mechanical performances, because a couple of GFs are agglomerated by thermal motion and strong interfacial adhesion and the local agglomeration does not break the global uniform distribution. This work shows that both the enhancement of GF content and the crosslinking reaction of PEN/GF composites are two key factors influencing the thermal and mechanical properties. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Spinnability and physical properties of in situ composite fibers based on thermotropic liquid crystalline polymer

In situ composite fibers based on poly(ethylene 2,6‐naphthalate) (PEN) and a thermotropic liquid crystalline polymer (Vectra A950) were prepared using a single‐screw extruder. The fibers were taken up at selected speeds. The spinnability, thermal behavior, mechanical properties, and morphologies of the PEN/Vectra A950 blend were investigated. The results showed that the PEN/Vectra A950 blends were partly miscible, and the miscibility increased with the increased concentration of Vectra in the blend. The DSC measurements indicated that Vectra enhanced the crystallization process of PEN by performing as a nucleating agent. The Instron tensile property study, coupled with scanning electron microscopy, revealed that the mechanical properties of the PEN matrix were significantly improved when Vectra existed as long and continuous fibrils. The laser Raman results showed that the Vectra orientation began to develop at take‐up speeds above 500 m/min. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 795–811, 2002     

Synthesis and properties of crosslinked poly(arylene ether nitriles) containing pendant phthalonitrile

In this study, poly(arylene ether nitriles) containing pendant carboxyl groups (PEN‐COOH) was first synthesized via nucleophilic aromatic substitution reaction from phenolphthalein, hydroquinone and 2,6‐dicholorobenzonitrile. Then, poly(arylene ether nitriles) with pendant phthalonitrile groups (PEN‐CN) was obtained via the Yamazaki–Higashi phosphorylation route from 4‐(4‐aminophenoxy)phthalonitrile (APN) with PEN‐COOH in the presence of CaCl₂, thus the phthalonitrile as pendant groups in PEN‐CN were easily crosslinked by further thermal treatment. The effect of crosslinking density on the thermal stabilities, dielectric properties and water absorption of the PEN‐CNs was investigated. These results showed that the T_g of PEN‐CN was improved from 182 to 213°C, dielectric constant (ε) was increased from 3.1 to 3.9, and dielectric loss (tan δ) was decreased from 0.090 to 0.013 at 1 kHz. The water absorption of PEN‐CNs after thermal crosslinking was <1.01 wt %, which showed excellent water resisting property. Therefore, this kind of poly(arylene ether nitriles) containing pendant phthalonitrile could be a good candidate as matrix resins for high‐performance polymeric materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Effect of different aromatic amines on the crosslinking behavior and thermal properties of phthalonitrile oligomer containing biphenyl ethernitrile

To find a proper amine to promote the processability of phthalonitrile‐based composites, three different aromatic amines: 4‐aminophenoxyphthalonitrile (APN), 2,6‐bis (4‐diaminobenzoxy) benzonitrile (BDB) and 4,4′‐diaminediphenyl sulfone (DDS) were used as curing agents to investigate the crosslinking behavior and thermal decomposition behavior of phthalonitrile oligomer containing biphenyl ethernitrile (2PEN‐BPh). Differential scanning calorimeter (DSC) and dynamic rheological analysis were employed to study the curing reaction behavior of the phthalonitrile/amine blends and prepolymers. The studies revealed that BDB was the preferred curing agent and the preferred concentration of BDB was 3 wt %. The thermal properties of the 2PEN‐BPh polymers were monitored by TGA, and the results indicated that all the completely cured 2PEN‐BPh polymers maintained good structure integrity upon heating to elevated temperatures and these polymers could thermal stabilize up to over 550°C in both air and nitrogen atmospheres. Dynamic mechanical analysis (DMA) showed the glass transition temperature (T_g) exceeded 450°C when the 2PEN‐BPh polymer post cured at 375°C for 8 h. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Interrelationship of thermal and mechanical properties of poly(ethylene terephthalate)/poly(ethylene 2,6‐naphthalate)/graphene nanocomposites

In the present work, attempts were made to investigate the thermal and mechanical properties of melt‐processed poly(ethylene terephthalate) (PET)/poly(ethylene 2,6‐naphthalate) (PEN) blends and its nanocomposites containing graphene by using differential scanning calorimetry and tensile test experimenting. The results showed that crystallinity, which depends on a blend ratio, completely disappeared in a composition of 50/50. By introducing graphene to PET, even in low concentrations, the crystallinity of samples increased, while the nanocomposite of PEN indicated reverse behavior, and the crystallinity was reduced by adding graphene. In the case of PET‐rich (75/25) nanocomposite blends, by increasing the nano content in the blend, the crystallinity of the samples was enhanced. This behavior was attributed to the nucleating effect of graphene particles in the samples. From the results of mechanical experiments, it was found in PET‐rich blends that by increasing the PEN/PET ratio, the modulus of samples decreased, whereas in the case of PEN‐rich blends, a slight increment of modulus is seen as a result of the increment of the PEN/PET ratio. The two contradicting behaviors were attributed to the reduction of crystallinity of PET‐rich blends by enhancement of PEN/PET ratio and the rigid structure of PEN chains in PEN‐rich blends. Unlike the different modulus change of PET‐rich and PEN‐rich blends, the nanocomposites of these blends similarly indicated an increment of modulus and characteristics of rigid materials by increasing the nano content. Furthermore, the same behavior was detected in nanocomposites of each polymer (PET and PEN nanocomposites). The alteration from ductile to rigid conduction was related to the impedance in the role of graphene plates against the flexibility of polymer chains and high values of graphene modulus. J. VINYL ADDIT. TECHNOL., 23:210–218, 2017. © 2015 Society of Plastics Engineers