PBT/AlPi/MPP/CB复合材料结晶及流变性能研究

以聚对苯二甲酸丁二醇酯(PBT)为基材,二乙基次膦酸铝(AlPi)以及三聚氰胺次膦酸盐(MPP)为阻燃剂、导电炭黑(CB)为抗静电剂,通过密炼熔融共混得到PBT/AIPi/MPP/CB阻燃抗静电复合材料。通过差示扫描量热分析(DSC),动态力学分析(DMA)和动态流变分析考察了阻燃抗静电PBT/AIPi/MPP/CB复合材料的熔融结晶性能,动态力学性能和动态流变性能。结果表明:阻燃剂和CB都会使复合材料提前结晶,结晶度提高;阻燃剂的添加使PBT的玻璃化转变温度升高,CB的加入会降低材料的内耗峰,阻燃剂和CB超过一定用量会使材料的储能模量降低;PBT/AIPi/MPP/CB复合材料的储能模量对剪切频率的依赖性不明显,而其复数黏度呈现强烈的剪切频率依赖性。     

PA66/GF/PPO共混材料的动态流变性能

通过熔融共混法在双螺杆挤出机上制备了尼龙(PA)66/玻璃纤维(GF)/聚苯醚(PPO)三元共混材料,采用旋转流变仪研究了共混材料的流变行为。结果表明,PA66及共混材料均为假塑性流体,呈现剪切变稀现象;GF和PPO的加入增大了共混材料的储能模量和损耗模量;用Han方法表明复合材料没有发生相分离;经动态时间扫描发现,共混材料的储能模量随着时间的增加而增大。     

PP/废PCB粉共混体系的动态力学性能分析

采用熔融共混法制备了聚丙烯(PP)/废印刷电路板非金属粉(废PCB粉)共混体系,利用动态力学性能分析法(DMA)研究了废PCB粉含量、改性剂聚丙烯接枝马来酸酐(PP-g-MAH)及振动频率对共混体系动态力学性能的影响。实验结果显示:PP/废PCB粉共混体系的储能模量和损耗模量较纯PP均有所增大,且随废PCB粉含量的增加进而增大,力学损耗因子峰值和玻璃化转变温度则有所下降;相容剂PP-g-MAH的加入使废PCB粉和PP之间形成较牢固的界面层,使共混体系储能模量较改性前进一步增加,而损耗模量和力学损耗因子峰值较改性前有所减小;振动频率对共混体系的动态力学性能亦有一定影响,随振动频率的增加,共混体系的储能模量提高,损耗模量和力学损耗因子峰值则有所减小。     

PA11/POE/POE-g-MAH共混合金的制备及性能研究

通过熔融共混法制备了聚酰胺11/乙烯-辛烯共聚物/马来酸酐接枝乙烯-辛烯共聚物(PA11/POE/POE-g MAH)三元共混合金,研究了POE-g-MAH及混合弹性体(POE/POE-g-MAH)的用量对该合金力学性能的影响。利用扫描电子显微镜(SEM)观察了PA11/POE/POE-g-MAH合金的冲击断面形貌,并采用动态热机械分析仪(DMA)表征了该合金材料的动态力学性能。结果表明:当混合弹性体POE/POE-g-MAH的配比为4/3,且其用量为25%时,PA11/POE/POE-g-MAH合金的综合力学性能最佳。适量POE-g-MAH的加入有助于弹性体分散相的细化,从而使弹性体粒子的粒径分布趋于均一,且分散均匀,并改善了PA11与混合弹性体间的相容性。混合弹性体与PA11共混后,能显著降低材料的动态储能模量,提高材料的韧性。     

原位聚合芳香型聚氨酯／环氧树脂共混材料的动态力学性能研究

以自制的芳香型二元醇为原料，用原位聚合的方法制备了芳香型聚氨酯厮氧树脂共混材料。系统地研究了二元醇含量对共混材料动态力学性能、冲击性能的关系。结果显示，对环氧树脂增韧的同时，低温下的储能模量基本上没有降低，玻璃化转化温度有所提高，体系为均相体系。     

阻燃香蕉纤维增强环氧树脂复合材料的动态力学性能和热性能研究

采用硅烷偶联剂(A-174)对香蕉纤维(BF)进行表面处理,采用硫酸铵、硼砂、磷酸氢二铵、磷酸三丁酯作为阻燃剂处理BF,选用添加了阻燃剂三聚氰胺焦磷酸盐(MPP)和季戊四醇(PER)的环氧树脂作为基体树脂,通过热压成型工艺制备阻燃BF增强环氧树脂复合材料。分别采用动态力学分析(DMA)、扫描电镜(SEM)、热重分析(TG)研究阻燃BF增强环氧树脂复合材料的动态力学性能、微观形貌以及热性能。结果表明:当阻燃BF含量为30%时,复合材料的储能模量、损耗模量达到最大值,分别比纯环氧树脂提高了570%和110%;当阻燃纤维含量为20%时,复合材料的玻璃化转变温度也比纯环氧树脂提高了16.9℃。通过扫描电子显微镜(SEM)观察说明纤维与环氧树脂之间产生良好的界面黏合作用,宏观上表现为动态力学性能的提高;热失重研究结果表明,阻燃BF的加入能明显提高环氧树脂的热分解温度和残炭率。     

混炼型聚氨酯橡胶/聚十二内酰胺热塑性硫化胶动态硫化历程与性能

采用动态硫化方法制备了混炼型聚氨酯橡胶（MPU）/聚十二内酰胺（PA 12）热塑性硫化胶（TPV）,通过控制动态硫化时间探究了该TPV的动态硫化历程,同时研究了不同动态硫化阶段共混物的物理机械性能和动态力学性能。结果表明,随着动态硫化时间的延长,MPU/PA 12 TPV逐步完成相转变,在温度和剪切作用下,MPU相由连续相转变为分散相,而PA 12则由分散相转变为连续相;随着动态硫化时间的延长,MPU/PA 12共混物的储能模量升高,损耗模量降低,损耗因子减小。此外,随着动态硫化时间的延长,MPU/PA 12共混物的综合力学性能提高。     

高性能无卤阻燃PA66的制备和性能研究

将白色颜料钛白粉、硫化锌与复配无卤阻燃剂三聚氰胺异氰尿酸盐(MCA)/三氧化二锑(Sb_2O_3)、尼龙66(PA66)共混,经双螺杆挤出机挤出造粒,制备无卤阻燃PA66复合材料,研究了不同阻燃体系对材料阻燃性能的影响,并对比了钛白粉、硫化锌对材料力学性能的影响,研究发现采用MCA+30%Sb_2O_3复配在添加10份时即能达到V-0(1.6 mm)级别,无卤阻燃PA66的拉伸强度、弯曲模量随着白色颜料钛白粉、硫化锌含量的增加而增加,缺口冲击强度随之减小,其中硫化锌对材料的力学性能影响相对较小,具有更好的缺口冲击强度。     

聚碳酸酯/尼龙6共混体系动态流变性能研究

采用平板动态流变仪研究了聚碳酸酯/尼龙6(PC/PA6)共混体系在设定温度下的动态流变性能,并探讨了增容剂用量、剪切频率等因素对高聚物动态复合黏度、动态储能模量及损耗因子等动态流变参数的影响。结果表明,PA6的加入明显改善了PC的加工流动性,3种增容剂的加入增强了分子间作用力和分子链之间的缠结,提高了界面黏合力。     

阻燃PC／ABS共混体系的动态力学分析

通过熔融共混法制备了阻燃PC／ABS复合材料,分析了其动态力学性能,探讨不同相容剂、不同ABS组份等因素对复合材料的储存模量（E′）、损耗模量（E″）、损耗因子（tanδ）等动态力学参数的影响。结果发现使用丙烯酸树脂和苯乙烯马来酸酐无规共聚物组成的复合相容剂能够较好地改善阻燃PC／ABS的相容性,在玻璃化温度附近E′和E″适中;材料有着良好的刚性和韧性,综合力学性能优良。研究结果可为进一步优化阻燃PC／ABS产品配方提供依据。     

Dynamic rheological behavior and mechanical properties of PVC/ACS blends

In order to increase the processability and mechanical properties of poly(vinyl chloride) (PVC), the terpolymer of acrylonitrile-chlorinated polyethylene-styrene (ACS) is used to modify the PVC. The plasticizing, rheological, and dynamic mechanical properties of PVC/ACS blends are investigated by means of torque rheometer, oscillation rheometer, and dynamic mechanical analyzer. The measurements of torque rheometer showed that both plasticizing time and stabilization torque are decreased with increasing ACS content. The PVC/ACS melts displayed larger dynamic storage modulus (G′), loss modulus (G′′), and complex viscosity (η*) than that of pure PVC, and these values reached maximum for the blend with 10 wt% ACS. When ACS content was below 10 wt%, PVC and ACS showed good compatibility in the blends by displaying a single T _g; however, when ACS content was more than 15 wt%, the phase separation phenomena occurred in the blends. PVC/ACS blends showed larger storage modulus (E′) and loss modulus (E′′) than that of pure PVC, but these values decreased with increasing ACS content. ACS can enhance both tensile and impact strength of PVC, and the impact strength reached maximum with 15 wt% ACS content which is higher 2.5 kJ/m² than the pure PVC. These results suggested that ACS is an efficient processing aid and toughening modifier for PVC at appropriate content.     

Dynamic mechanical properties of thermoplastic elastomers from polypropylene–natural rubber blend

The dynamic mechanical properties of thermoplastic elastomers from polypropylene natural rubber blends have been evaluated with special reference to the effect of blend ratio and extent of dynamic crosslinking of the elastomer phase. The effects of HAF black and silica fillers have also been studied. It has been found that increasing the proportion of elastomer phase reduced the storage modulus and increased the loss tangent values of the blends. The effect of dynamic crosslinking was found to be more prominent in blends containing higher proportion of elastomer phase. The improvement in storage modulus and decrease in loss tangent values were quite remarkable with increase in extent of crosslinking in these blends. The 70:30 NR:PP blend was found to exist as a two-phase system, both the components forming continuous phases of the blend.     

Thermal,mechanical, and morphological properties of polylactic acid toughened with an impact modifier

Polylactic acid (PLA) was melt‐blended with different amount (0 to 50 wt %) of a commercially available ethylene acrylate copolymer impact modifier. PLA/impact modifier blends were prepared via an internal mixer and compression molded into test specimens. The thermal, mechanical, and morphological properties of the blends were investigated. The addition of impact modifier decreased the ability of PLA to crystallize and/or recrystallize. The degree of crystallinity of PLA decreased while the cold crystallization temperature shifted to higher temperatures with increasing the impact modifier content. PLA/impact modifier blends were partially miscible. This was confirmed by the dynamic mechanical analysis (DMA) tests. With increasing the impact modifier content, the blends showed some improvement in the elongation at break and notched impact strength indicating the toughening effects of the impact modifier. In contrast, the yield stress and tensile modulus decreased with the increase in the impact modifier content. Scanning electron microscopy (SEM) micrographs revealed that the toughening mechanisms among others involved shear yielding or plastic deformation of the PLA matrix induced by interfacial debonding between the PLA and the impact modifier domains. PLA with 30 wt % impact modifier showed comparable yield stress and tensile modulus and better elongation at break and impact strength (+90%) than those of polypropylene (PP). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123:2715–2725, 2012     

Dynamic mechanical properties and morphology of poly(benzyl methacrylate)/epoxy thermoset blends

Poly(benzyl methacrylate) (PBzMA)/epoxy thermoset blends of composition 5 to 25 wt% of PBzMA were prepared curing with 4,4′diaminodiphenylmethane (DDM), to study the influence of composition on the morphology and dynamic‐mechanical properties of the blends. The cured blends are phase separated in PBzMA‐rich phase and epoxy rich‐phase. As the PBzMA content increases, the morphology evolves from nodular, to combined and to totally inverted. The analysis of the α‐mechanical relaxations indicates that the glass transition temperatures (T_g) of PBzMA and of epoxy in the blends are different from the neat polymers, this is related to a noncomplete phase separation on curing. The profiles of the loss modulus‐temperature curves are correlated with the change in morphology that appears increasing the PBzMA content. The storage modulus‐temperature curves are highly dependent on the morphology of the samples. The storage modulus‐composition dependence is predicted using several models for two phase composites. POLYM. ENG. SCI., 50:1820–1830, 2010. © 2010 Society of Plastics Engineers     

联苯型液晶聚氨酯/环氧体系的动态力学性能

采用动态热力学分析方法(DMA),研究了联苯液晶聚氨酯(DLCP)/环氧树脂(E-51)固化体系的储能模量、损耗模量和力学损耗因子随温度的变化情况。在玻璃化转变温度(Tg)下,通过改变振动频率求出链段运动的活化能并探讨聚合物分子链段的运动情况。结果表明:DLCP可降低材料的内耗,提高材料的Tg。加入质量分数5%的DLCP,复合材料的储能模量可达2 700 MPa,Tg比纯树脂提高10～30℃。     

Aspects of miscibility in poly(vinyl chloride)/epoxidized natural rubber blends. Part II: Dynamic mechanical properties

Miscibility in poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) blends was further investigated by means of dynamic mechanical analysis. The single glass transition temperature shown by the blends supported earlier observations of miscibility Furthermore, observed synergism in storage modulus has again reaffirmed the miscibility of these blends. A critical examination of the damping peaks at various compositions again revealed the microheterogeneous nature of the blends. Some theories relating glass transition temperature and modulus with miscibility were also used to examine miscibility. Agreement of the results with theories proposed by Gordon—Taylor and Kleiner has provided a further insight into the miscible nature of PVC/ENR blends.     

扩链剂增容PLA/PBAT共混物流变性能

通过熔融共混法制备了Joncryl ADR 4370F扩链剂增容聚乳酸/聚对苯二甲酸/己二酸丁二酯(PLA/PBAT)共混物,采用旋转流变仪分别研究了扩链剂和PBAT含量对PLA/PBAT共混物动态流变行为的影响.通过动态应变扫描确定了PLA/PBAT共混物的线性黏弹区,应变选取1％;PLA/PBAT共混物的储能模量和...     

用氯化钠－ 无水三氯化铝协同增容聚苯乙烯/三元乙丙橡胶共混物

在熔融状态下利用Friedel － Crafts 烷基化反应原位增容聚苯乙烯( PS) /三元乙丙橡胶( EPDM) 共混物,研究了不同的催化体系对PS /EPDM 共混物性能及动态流变行为的影响。结果表明,加入助催化剂氯化钠的催化体系有利于强化PS 与EPDM 间的接枝反应,同时降低EPDM 的交联反应,提高了PS /EPDM 共混物的力学性能; 动态力学分析结果表明加入助催化剂后PS /EPDM 共混物的储能模量和PS 的玻璃化转变温度均降低; 动态流变行为显示,在低频率区域,加入了助催化剂的共混物其动态储能模量、损耗模量和复数黏度均高于加入普通催化体系者,损耗因子低于普通催化体系; 从扫描电镜照片可以看出,加入助催化剂共混物的两相结合紧密,脆断面的橡胶粒子剥离空洞减少,相容性提高。