PC/ABS共混物的PGC-MS定量分析

采用裂解/气相色谱-质谱联用方法(PGC-MS)对制备的一系列已知配比的PC/ABS共混物进行分析。实验比较了650、750℃裂解温度下共混物的裂解质谱总离子流图,选择PC/ABS共混物的快速鉴定的裂解温度为750℃;通过对已知PC/ABS配比的共混物的特征裂解碎片进行定量分析,发现当共混物中ABS和PC的质量比不大于20∶100时,特征裂解碎片苯乙烯与苯酚的峰面积之比与共混物中ABS/PC的配比呈线性关系,该现象可作为PC/ABS共混物定量分析的依据。     

基于固体分散剂制样的裂解/气相色谱-质谱联用定量测定PC/ABS共混物比例

建立了以二氧化硅为分散剂制样的裂解/气相色谱-质谱联用测定聚碳酸酯(PC)/丙烯腈-丁二烯-苯乙烯共聚物(ABS)共混物比例的分析方法。将样品冷冻破碎成粉末后,以二氧化硅为固体分散剂与样品混合后进样,在600℃裂解温度下裂解得到相应的裂解色谱图,选择PC/ABS共混物裂解色谱图上ABS的特征裂解产物——苯乙烯为定量峰,计算PC/ABS共混物中ABS的质量分数,再进一步推算PC的质量分数。以二氧化硅为固体分散剂制备系列已知含量的PC/ABS分散体,以ABS含量为横坐标,对应的苯乙烯峰面积为纵坐标绘制校准曲线,ABS在分散体中含量在0.06～20 g/kg(对应PC∶ABS=99.7∶0.30～0∶100)范围内的线性良好,相关系数(r²)为0.994,以5倍信噪比(S/N=5)计算得到ABS的检出限为0.06 g/kg(对应的PC∶ABS比例为99.7∶0.30)。采用该方法对已知混合比例的PC/ABS样品进行测定,所得结果的回收率为95.3%～103%,相对标准偏差(RSDs,n=3)为1.1%～3.8%。该方法简便、准确度高,适用于PC/ABS共混物全范围比例的...     

PC/ABS及PC/ABS/PE-g-MAH共混体系相容性的研究

研究了聚碳酸酯与ＡＢＳ（ＰＣ／ＡＢＳ）及ＰＣ／ＡＢＳ与马来酸酐接枝聚乙烯共聚物（ＰＣ／ＡＢＳ／ＰＥ－ｇ－ＭＡＨ）共混体系的力学性能和应力开裂性能。用ＤＳＣ和ＳＥＭ研究了共混体系的相容性。结果表明：ＡＢＳ的加入能提高ＰＣ的冲击强度,ＡＢＳ的含量及品种影响ＰＣ／ＡＢＳ合金的力学性能,ＡＢＳ能提高ＰＣ的耐溶剂应力开裂性能。ＰＣ／ＡＢＳ／ＰＥ－ｇ－ＭＡＨ共混体系的力学性能和相容性优于ＰＣ／ＡＢＳ共混体系,     

新型含磷阻燃剂的合成及阻燃PC/ABS的热稳定性能

通过9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)、乙烯基甲基二甲氧基硅烷(WD-23)和γ-氨丙基甲基二乙氧基硅烷(DB902)之间的反应,合成了一种新型含磷阻燃剂:10-(乙基甲基二甲氧基硅烷)-9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物/γ-氨丙基甲基二乙氧基硅烷共聚物(DPWDF).利用热重分析(TGA)研究了阻燃剂及阻燃PC/ABS的热稳定性.结果表明:480 ℃以后,阻燃剂在空气氛围中的残炭量比在氮气氛围中的高;阻燃剂提前于基体PC/ABS分解,有利于促进基体成炭,提高基体的高温残炭量.     

ABS的MAH/St多单体熔融接枝及其对PA6/ABS共混体系相形态和力学性能的影响

通过多单体熔融接枝的方法制备出了具有较高接枝率的ABS接枝物 (ABS g (MAH co St) ) ,并对其接枝机理进行了初步探讨 .研究表明 ,MAH、St接枝ABS时 ,反应主要发生在ABS中聚丁二烯的双键部位 .同时 ,当MAH与St的用量比约为 1:1时接枝率达到最高 .ABS g (MAH co St)作为尼龙 6 (PA6 ) ABS共混体系相容剂起到了良好的增容效果 .实验证明 ,相容剂使用前后 ,共混物的相区尺寸由几十 μm减小到 1μm以下 ,且分布更加均匀 ;共混物的拉伸强度和冲击强度等力学性能也同时得到均衡改善 .     

SAN共聚物组成对PVC/ABS共混物相容性的影响

采用乳液聚合技术通过改变共聚单体的投料比(St/AN)合成了一系列不同AN结合量的ABS接枝共聚物粉料和SAN共聚物.将其与聚氯乙烯(PVC)和邻苯二甲酸二辛酯(DOP)熔融共混分别制得了PVC/ABS、PVC/SAN、PVC/ABS/DOP和PVC/SAN/DOP共混物,利用SEM、TEM和动态力学粘弹谱仪(DMA)对共混物的相容性和相结构进行了表征.结果发现,在PVC/ABS共混体系中,尽管改变接枝SAN共聚物的AN结合量,PVC和SAN共聚物均为不相容体系;在该共混物中引入增塑剂DOP后,虽然当SAN共聚物AN结合量小于23.4 wt%时,共混物在室温以上只存在一个tanδ峰,但形态结构研究结果表明共混物仍为不相容体系,共混物的相区尺寸明显地依赖于SAN共聚物中的AN结合量,当AN结合量为23.4 wt%时相区尺寸最小.     

PET/PC共混体系结晶行为研究进展

聚对苯二甲酸乙二醇酯(PET)／聚碳酸酯(PC)合金材料是综合性能优异的工程塑料,对其结晶行为的研究,可为设计,调节及控制材料的性能提供理论基础。评述了近年来PET／PC共混体系结晶行为研究的最新工作和理论进展,包括PET／PC共混体系酯交换、相容性及结晶性的关系,退火对PET／PC共混体系结晶行为的影响,第三组分对PET／PC共混体系结晶行为的影响,PET／PC共混体系结晶动力学以及PET／PC共混体系高压结晶行为的研究。并对今后的深入研究作了展望。     

PC/EAA共混体系在加工过程中的反应

采用差示扫描量热法(DSC)和核磁共振氢谱法(1H-NMR)研究了不同聚碳酸酯(PC)/乙烯-丙烯酸共聚物(EAA)共混体系在加工过程中的大分子反应,考察了有机金属催化剂二丁基锡DBTO)含量和反应时间对体系的影响.采用哈克(Haake)转矩流变仪的混合器作反应釜,索氏抽提器分离产物.结果表明,PC和EAA在加工中反应剧烈,在共混体系的界面原位形成接枝或交联的PC-EAA共聚物,随催化剂用量增大、反应时间延长易生成共交联的PC-EAA共聚物.但混合时间过长,体系的断链反应会加剧,生成产物不稳定.     

SMA/蒙脱石纳米复合材料增容PA6/ABS共混体系

采用原位插层法制备苯乙烯-马来酸酐交替共聚物/蒙脱石(SMA/MMT)纳米复合材料增容PA6/ABS共混体系,并与SMA及MMT的增容效果进行比较,运用TEM、SEM、DSC及XRD研究了增容剂SMA/MMT及MMT的增容机理.结果表明,采用SMA做增容剂,体系机械性能下降;MMT可使体系拉伸强度提高,但冲击强度下降;采用SMA/MMT纳米复合材料做为增容剂,可提高共混体系的强度及韧性.TEM、XRD、DSC及SEM研究结果表明,PA6/ABS/(SMA-MMT)体系中MMT主要分布于两相界面处,ABS及PA6分子链可进入MMT层间,形成类似于共聚物结构,起到增容剂的作用,从而降低分散相粒径,增加两相界面作用力,有利于体系力学性能的提高.PA6/ABS/MMT体系中MMT主要分布于连续相PA6中,虽然对分散相粒径影响较小,但增强了PA6相强度,使得体系力学性能提高.     

HQ-PPEK/PC共混物的相容性与流变性

聚芳醚酮;聚碳酸酯;共混物;流变性能;HQ-PPEK/PC共混物的相容性与流变性     

PC及PC/ABS共混物的疲劳裂纹扩展研究

研究了聚碳酸酯(PC)和PC/ABS高分子材料的疲劳裂纹扩展规律,利用改进柔度法测量其裂纹扩展速率,采用扫描电子显微镜(SEM)观察其断口形貌,分析疲劳裂纹扩展机理.在较大裂纹扩展速率(10-6～10-3mm/cycle)范围内,PC/ABS的疲劳裂纹扩展速率可以用Paris公式da/dN=9·5587×10-5(ΔK)2·88381来描述.高分子材料PC的疲劳裂纹扩展速率约为高分子材料PC/ABS的3倍.高分子材料PC/ABS疲劳裂纹面上的特征以韧窝为主,较低裂纹扩展速率对应较小的韧窝,较高裂纹扩展速率对应较大的韧窝.高分子材料PC疲劳裂纹面有明显的不连续裂纹扩展带,其裂纹面相对较平.     

STUDIES ON FLAME-RETARDANT PC/ABS MULTIPLE-ELEMENT ALLOY

The preparation technology of flame-retardant PC/ABS alloys was studied in this paper. Using a high-efficiencyflame retardant system and by means of multiple-ingredient compatibilizing, PC/ABS alloys with excellent impact strengthand flame retardant property were prepared. The experimental results showed that by using PS-g-MAH and SMA assynergistic compatibilizers, the notched Izod impact strength and flammability of PC/ABS alloy obtained in the present work can be up to 175 J/m and UL-94 V0, respectively.     

Effect of cyclic loading on tensile properties of PC and PC/ABS

The effects of cyclic loading on tensile fracture properties of polycarbonate (PC) and the alloy of polycarbonate and acrylonitrile-butadiene-styrene (PC/ABS) are experimentally investigated in the paper. Two digital cameras are used to record simultaneously the tensile deformation of specimens and the large deformation and the necking process of these polymers are discussed. Two lateral contractions are not identical at the later tensile stages and the contraction ratios in each lateral direction are related with the tensile strains in axial direction on width and thickness surface. The curvature radiuses at the minimum section during necking process are shown. The volume increases during necking process and then decreases gradually. The yield stress and fracture stress of PC/ABS are lower than that of PC. The degradation of the fracture stress and fracture strain due to the application of cyclic loading is larger for PC than that for PC/ABS, and these can be used to explain qualitatively why PC has higher fatigue crack growth rate than PC/ABS.     

PC/ABS blends: Compatibilization and mechanical behaviour

PC/ABS(M) blends, encompassing the whole composition range between pure PC and ABS(M), were prepared by melt-mixing in a Brabender-like apparatus. Thermal, mechanical and impact tests were performed on compression moulded specimens. Inward Tg shifts were detected for PC and ABS(M) in the blends with respect to pure PC and ABS(M) values, indicating an interaction between the component domains. This finding was confirmed by the comparison of the experimental tensile moduli with the Kernels model predictions, showing an evidence of a good adhesion between the phases. A synergistic effect was observed for the impact strength as well as for the maximum stress at an ABS(M) blend content of about 25 weight %. All the results are interpreted on the basis of an interlayer existing at the boundary between the PC and ABS phases. A preliminary investigation on the influence of the ABS internal composition, keeping constant all the other conditions (mixing, processing, specimen preparation), was carried out as well. Differences in the properties of PC/ABS(M) and PC/ABS(B) blends are thoroughly discussed. The compatibility between PC and ABS domains seems to be scarcely influenced by such a parameter in these blends.     

Determination of dual glass transition temperatures of a PC/ABS blend using two TMA modes

An inherent challenge with polymer blends is the difficulty in resolving the glass transition, T _g, for the smaller mass fraction component. The objective of this work was to determine the practical scanning conditions for identifying the dual T _g’s for a 75:25 polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blend using a thermomechanical analyzer (TMA). Scanning rates up to 20°C min⁻¹ using dilatometer and expansion modes were studied. Heating and cooling rates were found to affect both T _g values but the effects were not simple relationships. T _g values could either increase or decrease depending on the scanning rate applied. Higher rates resulted in large thermal lags which opened the accuracy of measurements to question. Generally, higher rates tended to display only one T _g but the duality of T _g’s can be detected with scanning rates between 0.5 and 5°C min⁻¹ for both modes.     

Evaluation of the thermal degradation of PC/ABS/montmorillonite nanocomposites

Polycarbonate (PC)/acrylonitrile‐butadiene‐styrene (ABS) polymer alloy/montmorillonite (MMT) nanocomposites were prepared using a direct melt intercalation technique. The pyrolytic degradation and the thermo‐oxidative degradation of the polymer alloy and the nanocomposites were studied by thermogravimetric analysis (TGA). The kinetic evaluations were performed by the model‐free kinetic analysis and the multivariate non‐linear regression. Apparent kinetic parameters for the overall degradation were calculated. The results show that PC/ABS/MMT nanocomposites have high thermal stability and low flammability. Their pyrolytic degradation and the thermo‐oxidative degradation model are different. The pyrolytic degradation reaction of the polymer is a two‐step parallel reaction model: nth‐order reaction model, and ath‐degree autocatalytic reaction with an nth‐order reaction autocatalytic reaction, whereas the thermal oxidative degradation reaction of the polymer is a two‐step following reaction model: A → B → C of nth‐order reaction model, and autocatalytic reaction model. Copyright © 2005 John Wiley & Sons, Ltd.     

PP/尼龙66/聚碳酸酯/ABS共混高聚物的SEM样品制作

讨论了PP／尼龙66／聚碳酸酯／ABS共混高聚物的扫描电子显微镜样品制作中存在的问题,通过实验,探讨了出该材料最佳的样品制作条件。     

人工神经网络方法用于PC/ABS材料定量分析

采用人工神经网络(ANN)算法建立了不同共混比的ABS/PC样品的近红外光谱数据与共混比的定量校正模型,并对校正模型的准确性进行了验证。实验分析结果表明,该方法适合于高分子材料共混比的测定。     

Thermal and structural analysis of ultrasonic-welded PC/ABS blend for automobile applications

PC/ABS thermoplastic blends are widely employed in manufacturing sectors, as it yields good mechanical behavior when subjected to dynamic loading conditions. While investigating the fundamental nature of PC/ABS blends, ultrasonic welding process appears to suit their joining as compared to other conventional techniques. This paper focuses on PC/ABS welding using ultrasonic and the subsequent investigation from the insight of thermal science. It is imperative for the materials to retain key properties after subjecting it to welding. Examinations to evaluate these properties through DSC reveal a lower onset temperature change and a small variation of glass transition temperature, respectively, for parts which indicate minimal changes in thermal properties in welded and non-welded specimens. Apparent activation energies determined from TG data are practically independent of heating rates, which suggests that the most important process in the degradation of these materials corresponds to ABS. Those mixtures with high PC content show a clear increase in apparent activation energies with heating rate, suggesting that the thermal degradation mechanism of these samples is composed of several complex processes, each predominant during different stages of the overall process. SEM is used to investigate the structural morphology of the welded parts.