PA6/EAA共混及共混物分子间相互作用、结晶行为的研究

在一定温度和剪切力作用下,以机械共混制备了PA6与EAA的共混物。通过溶剂溶解证明在共混过程中形成了部分接枝共聚物;用FTIR结合DSC探讨了共混中分子间的作用力及对PA6结晶性的影响。     

吸湿性PA6/PVP共混物的结构及性能研究

通过熔融共混的方法，在PA6中混入3％－10％的聚乙烯吡咯烷酮（PVP），使PA6共混物的吸湿性明显提高，随PVP加入量的增大，PA6结晶由γ型逐渐向α型转变，PVP与PA6形成了分子间氢键，FIIR和WAXD分析证明了分子间氢键的存在及PA6晶型的变化。     

树形分子对PA11/PA6共混物性能的影响

在PA11／PA6共混物中添加4．0代树形分子,提高了共混物的性能,研究了不同树形分子含量对共混物力学性能、耐热性和流动性的影响。结果表明,在PA11／PA6中添加0．25％树形分子后,共混物的拉伸强度、断裂伸长率明显提高,缺口冲击强度和维卡软化温度略有增加,但流动性有所下降。     

含超分子液晶结构的PA液晶与PA共混物的制备方法

一种含超分子液晶结构的PA液晶与PA共混物的制备方法，属于PA共混物液晶化自增强工程塑料领域。由于刚性分子与柔性分子聚合物的结构差异较大，二者很难形成分子级别相容的共混物。本发明首先合成PA液晶，然后利用溶液共混的方法，通过PA液晶和PA之间强烈的分子间氢键作用，将物质的量比为1：1的PA液晶与PA自组装合成了具有超分子液晶的共混物。     

PP/EVOH/PA6共混物的性能研究

以聚丙烯接枝马来酸酐(PP-g-MAH)为相容剂,制备了聚丙烯(PP)/乙烯-乙烯醇共聚物(EVOH/)聚酰胺6(PA6)共混物,研究了PP/EVOH/PA6三元共混物的相容性、流变性能、阻隔性能、力学性能、热性能及形态结构。结果表明:相容剂与EVOH和PA6间发生了反应,提高了共混物的相容性;相容剂的加入提高了PP、EVOH、PA6的结晶温度,增强了PP与EVOH和PA6间的黏合力,降低了界面张力;EVOH占EVOH/PA6总量68%的三元共混物吸油率最小,当相容剂用量为5份时,PP/EVOH/PA6三元共混物吸油率比PP/EVOH二元共混物降低了8%。     

树形分子对PA11／PA6共混物性能的影响

在PA11／PA6共混物中添加4．0代树形分子，提高了共混物的性能，研究了不同树形分子含量对共混物力学性能、耐热性和流动性的影响。结果表明，在PA11／PA6中添加0．25％树形分子后，共混物的拉伸强度、断裂伸长率明显提高，缺口冲击强度和维卡软件温度略有增加，但流动性有所下降。     

HDPE-g-GMA对PA6/UHMWPE共混物性能的影响

采用自制甲基丙烯酸缩水甘油酯接枝高密度聚乙烯(HDPE-g-GMA)作为增容剂来增容尼龙6/超高分子量聚乙烯(PA6/UHMWPE)共混物。通过Molau试验、红外光谱分析、扫描电子显微镜观察和物理力学性能测试,研究了HDPE-g-GMA在熔融共混过程中对PA6/UHMWPE共混物的增容作用。结果表明,HDPE-g-GMA与PA6发生化学反应所生成的接枝聚合物对PA6/UHMWPE共混物有较好的增容作用;PA6/UHMWPE共混物的界面形态和力学性能均有较大改善．吸水率也有所降低。     

PA6相对黏度对PA6/POE-g-MAH共混物缺口冲击性能的影响

研究了尼龙(PA)6相时黏度对PA6/马来酸酐接枝乙烯-辛烯共聚物(POE-g-MAH)共混物缺口冲击性能的影响.结果表明,PA6的相对黏度对PA6/POE-g-MAH共混物的缺口冲击断裂韧性有明显影响;低黏度PA6/POE-g-MAH共混物冲击断裂过程中的裂纹扩展功明显高于中、高黏度PA6/POE-g-MAH共混物;...     

吸湿性PA6/PEG共混物的研究

通过熔融共混的方法，在PA6中混入质量分数为3％－10％的聚乙二醇（PEG），使PA6共混物的吸湿性明显提高。随PEG加入量的增大，PA6共混物的拉伸强度有所下降而缺口冲击强度上升，说明PEG可以在PA6中发挥增塑作用。     

PA6/TPU共混物的结构与性能

采用X射线衍射仪、示差扫描量热仪和扫描电子显微镜测试了PA6／TPU共混物的结构和热性能。结果表明,PA6／TPU共混物为结晶高聚物,但其结晶度较PA6降低了15％左右;随着PA6／TPU共混物中TPU用量的增大,共混物的熔点降低,而结晶温度升高;当TPU用量为15份时,共混物的相态为“海一海结构”,具有良好的相容性。     

POM/HDPE共混物摩擦磨损性能研究

以(乙烯/丙烯酸)共聚物(EAA)为增容剂,采用挤出工艺制备了聚甲醛(POM)/高密度聚乙烯(HDPE)/EAA共混物,考察了不同含量的EAA对POM/HDPE共混物的摩擦磨损性能、力学性能的影响,并通过扫描电子显微镜对共混物的磨损表面形貌进行了观察和分析.结果表明,共混材料的磨损机制以粘着磨损为主,随着增容剂EAA含量的增加,共混物的摩擦因数和磨损量呈先减小后增大的趋势,当POM/HDPE/EAA的质量比为90/10/2时,摩擦因数和磨损量表现出最小值;加入增容剂EAA改善了共混物的相容性和力学性能.     

A study on the use of phenoxy resins as compatibilizers of polyamide 6 (PA6) and polybutylene terephthalate (PBT)

In this study we investigated the potential of phenoxy resins as compatibilizers in the blending of two high‐volume engineering thermoplastics—polyamide 6 (PA6) and polybutylene terephthalate (PBT), in an effort to establish the usefulness of blending as a method of recycling of mixed plastic wastes. It was found that phenoxy resins formed miscible blends with PBT, formed grafted copolymers with PBT through ester exchange reactions, and—though formed immiscible blends with PA6—produced energetic interactions in the form of hydrogen bonding with PA6. The ternary blend systems of 70 parts PA6, 30 parts PBT, and respectively 5, 10, and 30 parts phenoxy resins, all by weight, revealed at two‐phase nature—PA6 as the continuous phase and miscible blends of PBT and phenoxy resins as the dispersed phase—and were found to be stable to phase coarsening by annealing with mechanical properties at least as good as those of the component polymers.     

Filmability and properties of compatibilized PA6/LDPE blends

Blends of low density polyethylene (LDPE) and polyamide 6 (PA6), compatibilized with an ethylene‐acrylic acid copolymer (EAA), either alone or combined with a low molar mass bis‐oxazoline compound (PBO), have been processed in film blowing operations and the properties of the films have been investigated. Without of compatibilization, the filmability of the blend was very poor and no significant specimen was collected. As a result of the reactive compatibilization, the blends with EAA and even more with the EAA‐PBO, were processed successfully in film blowing. The films of the quaternary blends were shown to possess satisfactory mechanical properties as a result of fine and stable morphology. The results confirm the conclusion of a previous study, i.e., that the PBO fourth component may promote the in situ formation of PA6‐g‐EAA copolymers by reaction with both the functional groups of PA6 and the carboxyl groups of EAA. POLYM. ENG. SCI., 45:1297–1302, 2005. © 2005 Society of Plastics Engineers     

Effects of the blending time on the properties and non-isothermal crystallization behavior of PA6/EVOH blends

Both polyamide 6 (PA6) and ethylene vinyl alcohol copolymer (EVOH) have high fractional crystallinity. Non-isothermal crystallization kinetics is highly important for the design of processing operations. Furthermore, PA6 and EVOH undergo a chemical reaction to form copolymer when melt blended for a sufficiently long time. Therefore, the effects of the blending time on the mechanical properties, rheological properties, and non-isothermal crystallization kinetics of PA6/EVOH blends were investigated. Non-isothermal crystallization kinetics were analyzed through the Jeziorny and Mo′s equations, and the Mo′s equation more appropriately described the crystallization behavior of the blends. Mechanical properties, melt viscosity, and storage modulus gradually enhanced with an increase in the blending time, and the elongation at break first increased and then decreased with an increase in the blending time because when the blending time increased, the degree of the reaction between PA6 and EVOH increased, causing adhesion at interfaces and intermolecular interaction to enhance and causing a decrease in molecular chain fluidity. The former leads to an increase in the mechanical properties of the blend, and the latter renders the regular arrangement of chains for crystallization highly difficulty; hence, crystallization fractions in the blend gradually decrease.     

PA6含量对PVC/PA6共混物形态结构与力学性能的影响

以EVA-g-MAH为相容剂,将PVC与自制的低熔点PA6共混制备了PVC/PA6共混物。通过扫描电子显微镜(SEM)和力学性能测试研究了PA6含量对PVC/PA6共混物形态结构及力学性能的影响。SEM分析结果显示:随着PA6含量的增加,PVC/PA6共混物的分散相尺寸逐渐增大,当PA6含量为10%时,共混物中分散相的分散尺寸最小为1μm;当PA6含量为50%时,共混物为两相共连续结构;当PA6含量为60%时,共混物中PA6为连续相,PVC为分散相。力学性能测试结果表明:当PA6含量为10%时,共混物的缺口冲击强度和拉伸强度都较PVC有明显提高,分别提高了约50%与30%,达到了6.29kJ/m2和60MPa。采用差示扫描量热仪(DSC)研究了PVC/PA6共混物的结晶温度,检测结果显示:PVC/PA6共混物呈现非晶结构。     

The linear tearing properties of biaxially oriented PA6/MXD6 blending films

The main purpose of this work was to investigate the linear tearing properties of PA6/MXD6 films prepared by simultaneous biaxial stretching. The compatibility between PA6 and MXD6 and the thermal properties of the PA6/MXD6 composites were also investigated. The results showed that the tearing deviation of the blending films decreased from 100 to 3.8% when the MXD6 blend ratio increased from 0 to 25%, but the deviation increased when the MXD6 blend ratio continue to increase. It means that the PA6/MXD6 films with addition of 25 wt% MXD6 exhibited the best linear tearing properties. The differential scanning calorimetry results revealed that the addition of MXD6 reduced the melting temperature from 227.5 to 224.8°C and crystallization temperature of PA6 from 179.3 to 175°C due to the benzene ring structure of MXD6. The dynamic mechanical analysis results indicated that MXD6 exhibits favorable compatibility with PA6. In addition, it was found that the barrier properties of the biaxially oriented PA6/MXD6 films were extremely improved with the increase of MXD6 content.     

酯交换反应对PET／PA6共混体系性能的影响

研究了PET与PA6在熔融共混时的酯-酰胺交换反应。采用DSC、SEM、FTIR等测试手段探讨了酯-酰胺交换反应对组分熔点、结晶度及共混物形态的影响。结果发现：酯-酰胺交换反应产生的嵌段共聚物会使组分熔点降低，且反应程度越深熔点降低越多；组分的结晶度也随酯-酰胺交换反应程度的加深而降低；产生的嵌段共聚物可增加组分间的相容性，提高共混体系的力学性能。     

尼龙—12增韧改性聚甲醛的研究

采用尼龙１２，用机械共混的方法对聚甲醛进行增韧改性，并对共混物的形态，结构与力学性能进行测试与分析。研究发现，在ＰＯＭ／ＰＡ１２共混体系中，存在差氢键的相互作用。ＰＡ１２的加入，使得ＰＯＭ的熔体温度Ｔｍ下降，且共混体系的结晶度Ｘｃ和拉伸强度下降，ＰＡ１２的含量为５％时，共混物的缺口冲击强度达到最大值。     

PA6/载银沸石共混物结晶及流变性能的研究

将载银沸石与聚己内酰胺(PA6)进行共混,经熔融挤出制备PA6/载银沸石共混切片,并进行了结晶形态及流变性能分析.结果表明:PA6中载银沸石的引入产生了异相成核结晶,使PA6球晶变小,结晶度提高;PA6/载银沸石共混体系为假塑性流体,其表观粘度随剪切速率的增大而减小,随温度升高而降低,随着载银沸石含量的增加而减小;共混...     

Reactive compatibilizer precursors for LDPE/PA6 blends. II: maleic anhydride grafted polyethylenes

Several home made and commercially available polyethylene (PE) samples grafted with maleic anhydride (MA) (PE-g-MA) were used as compatibilizer precursors (CPs) for the reactive blending of low density PE (LDPE) with polyamide-6 (PA). Scope of the work was to compare the effectiveness of these CPs with that of a number of ethylene-acrylic acid copolymers (EAA), which had been employed in a previous study for the reactive compatibilization of the same blends, and to get a deeper insight into the coupling reactions producing the PA-g-CP copolymers that are thought to act as the true compatibilizers in these systems. To this end, binary CP/LDPE and CP/PA and ternary LDPE/PA/CP blends were prepared with a Brabender mixer and were characterized by DSC, SEM and solvent fractionation. The results show that the PE-g-MA copolymers react more rapidly with PA than the EAA copolymers and that their CP effectiveness depends critically on the microstructure and the molar mass of their PE backbones. In particular, the CPs produced by functionalization of LDPE were shown to be miscible with this blend component and to be scarcely available at the interface where reaction with PA is expected to occur. Conversely, the CPs prepared from the HDPE grades were immiscible with LDPE and showed better CP performance. Whereas the effectiveness of the EAA copolymers studied earlier had been shown to increase with an increase in the concentration of the carboxyl groups, the concentration of the succinic anhydride groups of the PE-g-MA CPs studied in this work was found to play a minor role, at least in the investigated range (0.3-3.0 wt% MA).