口腔洁治器用耐高温PBT制备及性能

聚对苯二甲酸丁二酯(PBT)因其热变形温度低,在高温湿热环境下时会产生变形,而影响其正常使用。而PBT热变形温度低的根本原因是由于其结晶度较低,因此,选用了三种无毒安全的成核剂和预处理方法来促进PBT结晶,提高其结晶度,从而提高其耐热性。主要研究了三种成核剂对PBT力学性能、热变形温度以及结晶性能的影响,实验结果表明成核剂B(二氧化钛)和成核剂C(苯甲酸钠)复配对PBT耐热性能的提高最有效,而热处理也能显著提高PBT的耐热性,可以得到热变形温度大于150℃的制品,同时,对于通过加入复合成核剂且经过热处理制备的PBT样条进行高温高压蒸煮和耐溶剂实验,结果表明,该样条耐热性和耐溶剂性都很好。     

成核剂对超微细滑石粉／聚丙烯共混物性能的影响

研究了α和β成核剂对滑石粉／聚丙烯共混物力学性能的影响。结果表明：α成核剂可以提高材料的拉伸强度、弯曲强度、弯曲模量和硬度等,冲击强度略有下降,而β成核剂使其韧性明显增强;α和β成核剂的加入皆使复合体系的耐热性显著提高,与β成核剂相比,β成核剂更能提高共混物的热变形温度。     

Effects of rosin‐type nucleating agent on polypropylene crystallization

In this investigation the effects of a rosin‐type nucleating agent, which was prepared from cocrystallizing of dehydroabietic acid and Na‐dehydroabietate, on polypropylene (PP) crystallization were studied. The results of differential scanning calorimetry and X‐ray diffraction proved that a cocrystal of dehydroabietic acid and Na‐dehydroabietate was formed. The lower melting point of the cocrystal caused it to be uniformly dispersed in PP. When cocrystals were added as nucleating agent, the mechanical properties, heat distortion temperature, and crystallization temperatures of PP were obviously improved, and the size of spherulites was also decreased. This proved that the cocrystals of dehydroabietic acid and Na‐dehydroabietate could act as an effective nucleating agent for PP. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1069–1073, 2002     

Effect of clay modification on the morphological,mechanical, and thermal properties of polyamide 6/polypropylene/montmorillonite nanocomposites

Polyamide 6/polypropylene (PA6/PP = 70/30 parts) blends containing 4 phr (parts per hundred resin) of organophilic montmorillonite (OMMT) were prepared by melt compounding. The sodium montmorillonite (Na‐MMT) was modified using three different types of alkyl ammonium salts, namely dodecylamine, 12‐aminolauric acid, and stearylamine. The effect of clay modification on the morphological and mechanical properties of PA6/PP nanocomposites was investigated using x‐ray diffraction (XRD), transmission electron microscopy (TEM), tensile, flexural, and impact tests. The thermal properties of PA6/PP nanocomposites were characterized using thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and heat distortion temperature (HDT). XRD and TEM results indicated the formation of exfoliated structure for the PA6/PP nanocomposites prepared using stearylamine modified montmorillonite. On the other hand, a mixture of intercalated and exfoliated structures was found for the PA6/PP nanocomposites prepared using 12‐aminolauric acid and dodecylamine modified montmorillonite. Incorporation of OMMT increased the stiffness but decreased the ductility and toughness of PA6/PP blend. The PA6/PP nanocomposite containing stearylamine modified montmorillonite showed the highest tensile, flexural, and thermal properties among all nanocomposites. This could be attributed to better exfoliated structure in the PA6/PP nanocomposite containing stearylamine modified montmorillonite. The storage modulus and HDT of PA6/PP blend were increased significantly with the incorporation of both Na‐MMT and OMMT. The highest value in both storage modulus and HDT was found in the PA6/PP nanocomposite containing stearylamine modified montmorillonite due to its better exfoliated structure. POLYM. COMPOS., 31:1156–1167, 2010. © 2009 Society of Plastics Engineers     

Effects of rosin‐type cocrystal nucleating agents on the crystallization process and the properties of polypropylene

A new kind of rosin‐type nucleating agent for polypropylene (PP), the cocrystal of dehydroabietic acid, potassium dehydroabietate, and sodium dehydroabietate, was prepared, and the effects of the nucleating agents on the mechanical and crystallization properties of PP were also studied. The results of differential scanning calorimetry and X‐ray diffraction proved that the cocrystal of dehydroabietic acid and compound alkali dehydroabietate was formed rather than a simple blend of dehydroabietic acid and single alkali dehydroabietate. When it was added to PP, the size of the PP spherulite decreased; the mechanical properties, crystallization temperature, and transparency of PP were substantially improved. Thus, the cocrystal of dehydroabietic acid, potassium dehydroabietate, and sodium dehydroabietate acted as a more effective nucleating agent for PP. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2137–2141, 2003     

聚丙烯的高性能化研究

在小型反应器内合成了不含及含有成核剂的聚丙烯(PP)、双峰聚丙烯(BMPP)和聚丙烯共聚物(PPc)，并用纳米CaCO3改性PPc。研究结果表明：釜内成核的PP和BMPP的弯曲模量和热变形温度显著增加，结晶温度和结晶速率明显提高，BMPP的拉伸强度也较PP大幅增加；但成核剂对PPc的性能影响不大，而加入纳米CaCO3后则使PPc的力学性能和结晶温度同步显著增加。     

Study on cellulose and xylan filled polypropylene composites

The thermal and viscoelastic properties of polypropylene (PP)/cellulose as well as PP/Xylan composites were investigated by differential scanning calorimetry (DSC) and dynamic mechanical thermoanalysis (DMTA). Morphological aspects were available by using polarizing light microscopy and scanning electron microscopy (SEM). Three types of fillers were incorporated in PP: xylan fillers (XL), cellulose microfibers (CM) and short fibers of spun cellulose (CS). The compatibilizer maleic anhydride modified PP (MAPP) was added to the composites. The crystallization temperature and crystallinity of PP apparently increased in the presence of all fiber types. The cellulose fiber surfaces act as nucleating agents for PP, resulting in the formation of transcrystalline regions around the fibers. The DMTA spectra of PP/filler composites revealed a significant increase in the stiffness and a remarkable decrease of the damping values. This effect was stronger for PP/CS than for the other composites. The results verify that improved compatibility and interfacial adhesion between fiber and matrix markedly contribute to an improvement of the mechanical properties. Received: 30 October 1997/Revised version: 11 December 1997/Accepted: 12 December 1997     

成核剂TM-3与苯甲酸钠对聚丙烯力学性能的影响比较

研究和对比了透明成核剂TM-3与普通成核剂苯甲酸钠(SB)对聚丙烯(PP)力学性能的影响,结果发现:TM-3与SB对PP的力学性能的影响有很大不同;随着成核剂含量的提高,PP/TM-3体系拉伸屈服强度基本不变化,而PP/SB体系出现了小小的波动,先下降后上升;PP/TM-3体系缺口冲击强度随成核剂含量增加呈线性增长,而PP/SB体系在苯甲酸钠含量为1%(质量分数)时出现了极大值;PP/TM-3体系弯曲强度随成核剂含量增加先下降而后上升,但PP/SB体系也是在苯甲酸钠含量为1%(质量分数)时出现极大值。另外,还研究了两种体系改性PP的断裂伸长率和成型收缩率。     

注塑条件对长玻纤增强聚丙烯性能影响研究

利用熔融浸渍装置,采用长玻纤(LGF)增强双马来酰亚胺等改性的聚丙烯(PP),制备了LGF增强PP复合材料。研究了在螺杆转速为80～250 r/min、背压为8～10 MPa的注塑条件下,复合材料的纤维长度、力学性能与热变形温度的变化。在研究范围内,注塑工艺参数的变化对复合材料的弯曲强度和热变形温度没有明显的影响,但随着螺杆转速的提高,纤维长度下降,所得复合材料的冲击强度先降低后升高。     

磷酸酯钠盐协同滑石粉制备高刚、耐热聚丙烯

采用直接混合法制得聚丙烯/滑石粉（PP/Talc）体系和聚丙烯/成核剂磷酸酯钠盐/滑石粉(PP/NA-40/Talc)体系,研究了Talc的添加量对两种复合体系的力学性能、耐热性能、流动性能以及结晶温度的影响,从动力学角度解释了力学性能提升的原因。结果表明,在PP中加入0.2 %（质量分数,下同）的NA-40和10 %的Talc时,使PP弯曲模量达到2 316.0 MPa,热变形温度达到120.0 ℃,结晶温度达到132.9 ℃,流动性能基本不变,从而满足高刚、耐热PP的使用需求。     

有机磷酸盐与硅溶胶复配成核剂对PP性能的影响

利用偏光显微镜(PLM)、光电雾度仪、差热分析(DSC)及力学性能测试考察有机磷酸盐(NA-21)与硅溶胶复配成核荆对均聚聚丙烯(PP)透明性、结晶行为及力学性能的影响.研究结果表明:有机磷酸盐与硅溶胶有良好的协同异相成核作用;复配体系中,纳米微粒的分散性明显好于添加单一纳米成核剂的分散性;硅溶胶的添加量为0.15%,有机磷酸盐的添加量为0.35%时,成核PP的雾度降低到36.3%,结晶温度升高到132℃;与单-NA-21增透PP相比,复配成核荆增透PP的冲击强度与拉伸强度都有明显提高.     

基于滤板应用的β成核剂增韧改性聚丙烯研究

针对目前国内通用的板框压滤机聚丙烯（PP）滤板框在使用中出现的开裂问题,通过添加β成核剂并利用差示扫描量热仪和偏光显微镜等研究了PP的力学性能、热变形温度、结晶行为及晶体形态的变化。结果表明,随着β成核剂含量增加,PP的拉伸强度和拉伸模量呈先下降后上升的趋势,断裂伸长率和冲击强度呈先上升后下降的趋势;当β成核剂含量为0.05 %（质量分数,下同）时,PP中的β晶接近完善,β晶的相对含量激增至85.25 %,此时样品的冲击强度增至纯PP的4倍,拉伸强度和拉伸模量损失较小;当β成核剂含量为0.50 %时,样品的热变形温度较纯PP提升约40 ℃。     

成核剂YS-688改性抗菌PP薄膜的研究

以聚丙烯（PP）为基体树脂,改性载银磷酸锆为抗菌剂,YS-688（二苄叉山梨醇衍生物）为成核剂,制备抗菌剂母粒、成核剂母粒和抗菌PP薄膜,研究了成核剂改性抗菌PP薄膜性能。结果表明：经YS-688改性的抗菌PP薄膜,球晶尺寸减小,结晶密度增大,结晶温度提高;含0．9％改性载银磷酸锆和0.3％YS-688的PP薄膜,其拉伸强度（纵向／横向）51．16／31．88MPa,透光率88．8％,雾度2．9％,对金黄色葡萄球菌和大肠杆菌抗菌率为99．26％和99．57％,物理力学性能和抗菌性能优良。     

聚丙烯釜内釜外成核评价

借助于热分析和力学性能测试考察了釜内与釜外添加成核剂对聚丙烯(PP)结晶行为和力学性能的影响。研究结果表明：2种添加方式对PP结晶温度影响不大,而釜内成核方式能更进一步提高结晶速率,成核PP的弯曲模量、低温抗冲击性能和热变形温度显著提高。     

Isothermal crystallization behavior and properties of polypropylene/EPR blends nucleated with sodium benzoate

The effect of sodium benzoate on the isothermal crystallization behavior of isotactic polypropylene (iPP)/ethylene–propylene rubber(EPR) blends was investigated using differential scanning calorimetry. Dynamic mechanical and physical properties of the iPP/EPR blends nucleated with sodium benzoate were also measured. It was found that the crystallization behavior and physical properties such as heat deflection temperature (HDT), flexural modulus, and impact strength were strongly affected by the competition between the nucleating effect of EPR attributed to its partial compatibility with iPP and the simple addition of the amorphous component, as well as the nucleating effect of sodium benzoate. High impact strength was achieved by addition of EPR and sodium benzoate to iPP. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 201–211, 2002     

Influence of heat treatment on the heat distortion temperature of poly(lactic acid)/bamboo fiber/talc hybrid biocomposites

Influence of heat treatment and fillers on the heat distortion temperature (HDT) of poly(lactic acid) hybrid biocomposites was intensively studied through HDT testing, polarizing microscope (POM), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). With loading 20 wt % BF or 20 wt % talc, improvement of HDT in PLA composite was about 10°C comparing with neat PLA after heat treatment. Moreover, there was a great improvement (above 45°C) of HDT in PLA composites with loading 20 wt % BF and 20 wt % talc simultaneously after heat treatment. Transcrystallization was observed during heat treatment and isothermal crystallization of PLA composites with loading BF and talc simultaneously. There was no similar phenomenon in other PLA composite with loading only one filler. The possible mechanism of forming transcrystallization was proposed. DSC and DMA were also used to clarify the variation in HDT before and after heat treatment, and the results suggest that the crystallinity, modulus and glass transition changed, especially formation of transcrystallization played a key role in improvement of HDT in PLA composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

玻纤增强阻燃PET的研制

研制了一种玻纤增强阻燃聚对苯二甲酸乙二酯(PET),着重考察了滑石粉、苯甲酸钠、Na2CO3、硬脂酸镁、ZnO及自制的几种结晶成核剂对材料力学性能和熔体流动速率的影响。结果表明,在没有加入结晶成核剂的情况下,单独加入玻纤对PET的增强增韧效果并不明显;适当的结晶成核剂能明显提高玻纤增强PET的力学性能,并改善其熔体流动性,促进PET制品定型,缩短生产周期;添加12份十溴二苯醚/Sb2O3复合阻燃剂,可使玻纤增强PET的阻燃性能达到UL94 V-0级。     

不同成核剂成核聚丙烯的结晶行为与力学性能

制备了６种成核剂成核聚丙烯（ＰＰ）母料研究了成核母料和成核母料／ＰＰ的结晶,熔融行为,力学性能和透明性等物理性能,不同成核在成核母材料和成核母料／ＰＰ中对ＰＰ的结晶与熔融行为以及性能有不同的作用,观察到成核型Ａ成核ＰＰ具有较高的结晶温度与综合性能,而成核剂Ｂ成核ＰＰ的透明性较好。     

β成核剂对聚丙烯力学性能的影响

通过在抗冲聚丙烯基础树脂中添加自主研制的酰胺型高效β成核剂,在升高聚丙烯耐热温度的同时有效提高聚丙烯树脂EPS30R的冲击强度,研究酰胺型β成核剂PA-01、TMB-5和FB-1添加量对聚丙烯树脂EPS30R力学性能的影响,通过微观形态分析增韧的内在原因,并考察成核剂对聚丙烯树脂EPS30R的成核效果。结果表明,添加β成核剂后,聚丙烯的力学性能明显改善,且β成核剂诱导聚丙烯的成核效果较好。     

新型α和β成核剂对PP结晶和力学性能的影响

在聚丙烯(PP)中加入两种新型成核剂:二苄叉山梨醇衍生物YS-688(α成核剂)和芳酰胺类化合物TMB-5(β成核剂),通过密炼–挤出的方法制备了PP/成核剂共混物材料。通过偏光显微镜、X射线衍射、差示扫描量热和力学性能测试研究了这两种成核剂对共混物结晶和力学性能的影响。结果表明,两种成核剂在适量时均能提高PP的结晶速率和结晶度,细化晶粒,且使晶体界面模糊,其中TMB-5具有较强的诱导PPβ晶成核的能力,当其质量分数为0.075%时,可使PP形成树枝状的β晶,而YS-688未改变PP的晶型,只生成了α晶。YS-688可提高共混物的拉伸强度,而TMB-5对共混物的拉伸强度影响很小;当两种成核剂质量分数均为0.075%时,共混物的韧性最好,相对于纯PP,PP/YS-688共混物的常温和–30℃缺口冲击强度分别提高了37.41%和12.76%,拉伸强度提高了11.11%;PP/TMB-5共混物的常温和–30℃缺口冲击强度分别提高了100%和55.41%。