近红外光谱分析技术在PA6生产中的应用

介绍了实际工作中采用近红外光谱分析技术建模时应注意的要点,以及使用Thermo Fisher近红外光谱仪对PA6生产中调配用添加剂不同组分进行光谱分析与检测。通过对比理论值与实际测试结果,确定光谱分析技术在调配工艺中的可行性;经过实际建立模型、校正、实际样品检测等过程后对模型进行验证和评价。     

Preparation and rheological behaviors of PA6/SiO2 nanocompiste

The polyamide 6 (PA6)/SiO₂ nanocomposites were prepared by in situ polymerization and the rheological behaviors were investigated. The morphology of resultant materials was characterized by scanning electron microscopy (SEM) and the rheological behaviors were characterized by capillary rheometer. The results showed that the SiO₂ particle size was around 50 nm and the particles dispersed evenly in PA6 matrix. The nanocomposites were pesudoplastic fluids and the apparent viscosities of nanocomposites increased initially and then decreased with the increase in nano-SiO₂ content at the same temperature. The non-Newtonian indexes of nanocomposites were smaller than those of pure PA6. With the increase in nano-SiO₂ content the apparent viscous activation energies of nanocomposites increased initially and then decreased. The rheological behaviors revealed that there were strong interactions between PA6 macromolecule chains and nano-SiO₂ particles.     

PC／PA6共混体系的耐溶剂性及其结晶行为的研究

聚碳酸酯(PC)易于应力开裂,耐化学腐蚀性差,尼龙(PA6)的加入可以改善PC的耐药性、耐应力开裂性。本实验以二甲苯为溶剂,对空白PC以及改性后的PC/PA6共混物进行浸泡,对其浸泡前后的物理机械性能以及样品宏观表面情况进行观察比较和分析,探讨了POE-g-MAH、PE-g-GMA两种不同相容剂及其用量和添加剂滑石粉对PC/PA6共混体系物理机械性能、耐溶剂性能、结晶性能等方面的影响。结果表明,PA6的加入可明显改善PC的耐二甲苯溶剂性能,滑石粉能进一步改善其耐溶剂性能,但添加量过多会致使冲击强度下降而限制材料的应用;POE-g- MAH、滑石粉较PE-g-GMA更有利于PA6的结晶,这可能与其异相成核或反应增容的作用有关;POE-g-MAH可明显地提高PC/PA6共混体系的相容性,且5%为较合理的添加量。     

PPO／PA6／弹性体多相共混物的流变行为

采用Ｉｎｓｔｒｏｎ３２１１毛细管流变仪对不同用量的ＳＥＢＳ和ＰＯＥ－ｇ－ＭＡＨ两种弹性体增韧改性的ＰＰＯ／ＰＡ６多相共混物的流变行为进行了测试。对比了两种弹性体在不同温度和剪切速度下对共混体系表观粘度的影响。     

Influence of biaxial stretching mode on the crystalline texture in polylactic acid films

Structural evolution during simultaneous (SB) and sequential rubbery state biaxial stretching (SEQ) of polylactic acid (PLA) films from cast amorphous precursors was investigated. Simultaneous biaxial stretching always leads to films with in-plane isotropy and poor crystalline order. In the first stage of sequential biaxial stretching, oriented crystallization gradually develops while transverse isotropy is maintained. Application of transverse stretching to these films possessing semicrystalline structure gradually destroys the crystalline structure oriented in MD during this realignment while establishing a second population of oriented but poorly ordered crystallites in TD. This destruction is caused primarily by splaying action under transverse stretching as evidenced by the decrease of crystallite sizes in MD.     

ABS-g-MAH对PA6/ABS合金性能的影响研究

以马来酸酐(MAH)接枝丙烯腈-丁二烯-苯乙烯共聚物(ABS)作为相容剂,研究了相容剂ABS-g-MAH对PA6/ABS合金凝聚态结构和力学性能的影响。结果表明,当ABS-g-MAH质量分数为20%时,合金的冲击强度比未加相容剂的提高了41%。动态力学性能(DMA)和偏光显微镜也很好地说明了加入相容剂的合金,其相容性得到了很好的改善。ABS和ABS-g-MAH的加入明显改善了PA6的吸水性能,当ABS-g-MAH质量分数为10%时,合金吸水率较纯PA6降低了50%。     

PA6/PC/POE/HDI复合物的性能研究

以尼龙6为主要原料,在聚碳酸酯(PC)和聚烯烃弹性体(POE)复合增韧的基础上,加入扩链剂(HDI),经反应挤出制备了具有超韧性的新型尼龙6工程塑料。探讨了不同HDI用量对复合物力学性能的影响,并对相关热性能和流变性能做了比较研究。结果发现,HDI的加入能够显著提高PA6和PC之间的相容性,同时复合物的黏度显著提高,结晶度有所降低。     

拉伸热定型对PET-PA/PA6共混纤维结构与性能的影响

以聚酯-聚酰胺共聚物/聚酰胺6(PET-PA/PA6)共混物为原料,采用熔融纺丝法制备了PET-PA/PA6共混纤维,讨论了拉伸热定型工艺对PET-PA/PA6共混纤维结构与性能的影响。结果表明:随拉伸倍数的增大,PET-PA/PA6共混纤维的断裂强度、取向度、结晶度以及沸水收缩率均明显增大;拉伸温度和热定型温度对PET-PA/PA6共混纤维的断裂强度和取向度的影响相对较小;随拉伸温度的升高,PET-PA/PA6共混纤维的断裂强度、取向度和结晶度呈现先增大后减小的趋势,并在拉伸温度为85℃时出现最大值;随热定型温度的升高,PET-PA/PA6共混纤维的结晶度增大、沸水收缩率减小;较佳的工艺条件为拉伸倍数1.6,拉伸温度85℃,热定型温度150℃。     

相容剂对PP/PA6/nano-CaCO3三元复合材料性能的影响

分别以PP-g-MAH和POE-g-MAH为相容剂,制备了聚丙烯/尼龙6/纳米碳酸钙(PP/PA6/nano-CaCO3)三元复合材料。研究了不同相容剂对PP/PA6/nano-CaCO3复合材料力学性能和微观结构的影响,确定了最佳相容剂及其用量。结果表明:相容剂对PP/PA6/nano-CaCO3复合材料具有良好的界面改性效果,其中POE-g-MAH的改性效果较佳。     

用于PA6/PP共混体系的改性聚丙烯相容剂研究进展

论述了用于PA6/PP共混体系的改性聚丙烯相容剂的制备方法及其进展,重点介绍了增韧改性尼龙6相容剂的常用接枝方法。     

聚丙烯/尼龙6/蒙脱石新型膨胀型纳米复合阻燃材料的研究

采用尼龙6（PA6）代替季戊四醇（PT）作成炭剂组成新型的膨胀型阻燃剂（IFR）,用熔融插层法成功制备了聚丙烯（PP）／PA6／有机化蒙脱石（OMMT）新型膨胀型纳米复合阻燃材料。用X射线衍射分析（XRD）和扫描电镜（SEM）观察OMMT层间距的变化和材料的微观结构,用热重分析（TG）、极限氧指数（LOI）测试和垂直水平燃烧测试研究了其阻燃性能,并考察了纳米复合材料的力学性能。研究结果表明,OMMT的层间距由2．200nm扩大到2、800nm,加入质量分数为4％-6％的OMMT的复合材料不仅使材料的拉伸强度和冲击强度提高了15％和69．5％,还提高了材料的阻燃性能,使剩炭率增加了12．32％,LOI达到22％,燃烧测试达HB级,其综合性能最佳。     

环氧树脂对PPS/PA6合金形貌及性能影响的研究

用环氧树脂作为聚苯硫醚(PPS)与尼龙6(PA6)共混体系的相容剂,采用熔融共混的方法制得了PPS/PA6合金材料.主要研究了环氧树脂(EP)用量对PPS/PA6(7:3)共混物的机械性能、相容性及形貌的影响.研究表明:EP的加入在一定程度上增加了体系的相容性;PA6呈分散相分散于PPS相中,随着EP用量的增加,在与流动方向垂直的断面上,分散相尺寸逐渐变大且呈现南圆形到不规则形状的转变;随着EP用量的增加,体系的冲击性能、拉伸性能、弯曲性能都呈现先升高后降低的趋势.     

硅烷交联聚乙烯/尼龙6阻隔材料的研究

通过硅烷交联聚乙烯与尼龙6共混制备阻隔材料,研究了硅烷交联聚乙烯的交联时间及尼龙6含量对复合材料阻隔性能、力学性能及热性能的影响。结果表明:随着交联时间的增长,材料的阻隔性能有所提高,当交联时间为6h时,表现出良好的阻隔性能;尼龙6含量对材料的阻隔性能和力学性能具有双重影响,当尼龙6含量为16%时,阻隔材料综合性能较好。     

尼龙6在热氧老化中的性能与结构变化

通过挤出共混法制备了添加不同抗老化助剂的尼龙6(PA6),以改善PA6的耐老化性能。考察了PA6试样暴露在125℃的热空气中一定时间后其黄色指数(YI)、色差(△E)、热稳定性能和力学性能的变化;系统地研究了不同抗氧剂对PA6在这一热氧老化过程中的变色行为和力学性能的影响;以黄色指数值达到55作为失效的指标,对PA6热氧老化试样进行了静态使用寿命的分析与预测;使用红外光谱(FTIR-ATR)分析了PA6试样在热氧老化过程的结构变化。研究结果表明:使用胺类抗氧剂能明显地改善PA6的抗热氧老化变色性能,还能使其保持较高的热稳定性能和力学性能,并大大延长PA6的静态使用寿命;用酚类抗氧剂/亚磷酸酯抗氧剂组成(1:1)的稳定体系能对改善PA6的耐热氧老化性能产生协同效应。     

氯化钙对尼龙6/硫酸钙晶须增强材料结构与力学性能的影响研究

本文用熔融共混法成功制备氯化钙/(尼龙6/硫酸钙晶须)复合力学增强材料,采用DSC、FTIR、XRD研究氯化钙对尼龙6/硫酸钙晶须复合材料结构性能的影响。结果表明:与硫酸钙晶须对尼龙6起异相成核作用的机理不同,引入少量的氯化钙对尼龙6的结晶性能、分子链间作用力产生很大影响;且当CaCl2含量3%时,PA6拉伸强度能提高至33%左右,缺口冲击强度有小幅度降低。     

PE—g—MAH对HDPE／PA6共混合金的增容作用

利用ＤＳＣ研究了ＰＥ－ｇ－ＭＡＨ对ＨＤＰＥ／ＰＡ６共混体系的增容作用,并讨论了ＰＥ－ｇ－ＭＡＨ对ＨＤＰＥ／ＰＡ６共混物的混容性能和力学性能的影响。结果表明：ＰＥ－ｇ－ＭＡＨ能有效地增强ＨＤＰＥ／ＰＡ６共混体系两相界面的相互作用,改善ＨＤＰＥ和ＰＡ６的相容性,是效果较好的增容剂。适量的ＰＥ－ｇ－ＭＡＨ的加入可使ＨＤＰＥ／ＰＡ６共混合金的可混性能提高,并有一定的增强作用。     

二丙基次膦酸铝和氢氧化镁对PA6的复合阻燃作用

通过极限氧指数测定、垂直燃烧实验和锥形量热分析研究了二丙基次膦酸铝(ADPP)和氢氧化镁(MH)对尼龙6(PA6)的复合阻燃作用。结果表明:ADPP与MH对PA6无协同阻燃作用,ADPP复配少量的MH(质量分数10%)阻燃PA6的LOI和垂直燃烧级别变化不大,总热释放量(THR)和最高热释放速率(PHRR)略有增加,但热稳定性有明显改善。残余物分析结果表明,复合少量的MH略增加了材料的成炭性,但炭层结构变得比较松散,因而对ADPP阻燃PA6的影响不大。而随着MH用量增加,成炭性明显下降,因而降低了ADPP对PA6的阻燃作用。     

Melt Rheological and Thermoresponsive Shape Memory Properties of HDPE/PA6/POE-g-MAH Blends

High density polyethylene (HDPE)/nylon6 (PA6) blends were prepared by means of melt extrusion and using ethylene – octane copolymer graft maleic anhydride (POE-g-MAH) as a reactive compatibilizer. Phase morphology, rheological and thermoresponsive shape memory properties of the blends had been studied. The results showed that addition of POE-g-MAH could increase compatibility and phase-interfacial adhesion between HDPE and PA6, decrease the temperature sensitivity of the melt, improve the shape memory property and processability of HDPE/PA6 blends. The shape recovery rate of HDPE/PA6/POE-g-MAH (80/20/10) blend is 96.5% when the stretch ratio is 75% and optimal shape recovery response temperature is 135°C.     

Solid-state nuclear magnetic resonance of the PA6/PC,PA6/PPO,and PA6/PC/PPO blends

The effect of mixing time is very important to plasticization and/or occurrence of chemical reaction between polyamide 6/poly(propylene oxide), polyamide 6/polycarbonate, and polyamide 6/polycarbonate/poly(propylene oxide) blends. The systems were investigated through solid-state carbon-13 cross-polarization magic angle spinning with variable contact time in the NMR experiment. In the systems, polycarbonate can prevent the antiplasticization effect already observed in the polyamide 6/poly(propylene oxide) blend. Therefore, it was verified that the addition of polycarbonate in the polyamide 6/poly(propylene oxide) system causes a hardening of the blend. This fact can be attributed to the restriction of the mobility of the NH group, probably influenced by the type of interaction that occurs in the polyamide 6/polycarbonate/poly(propylene oxide), due to the effect of poly(propylene oxide), which can be act as an interfacial agent promoting a better interaction between polyamide 6 and polycarbonate. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 129–133, 1998     

Influence of Grafting Degree on the Morphology and Mechanical Properties of PA6/POE-g-GMA Blends

Poly(ethylene-1-octene) (POE) was functionalized to varying degrees with glycidyl methacrylate (GMA) by melt grafting processes. Fourier transform infrared spectra (FT-IR) and ¹H NMR spectra confirmed that glycidyl methacrylate was successfully grafted onto the POE. The data from GPC measure demonstrated that POE chains degraded during grafting process. The POE-g-GMA elastomers were used to toughen nylon. The mechanical properties, fracture surface morphology and the dispersal phase size were investigated. Results showed that the grafting degree strongly influenced the morphology, mechanical properties and the dispersal phase size of PA6/POE-g-GMA blends.