聚丙烯共聚物新品种的开发及需求

简介了国内外各种新聚丙烯共聚物的性能、生产方法及开发概况 ,另外 ,也介绍了其在中国市场的需求。     

聚丙烯／接枝木纤维复合材料相容性及性能的研究

为了改善木纤维与聚丙烯基体间的相容性,用马来酸酐接枝聚丙烯（ＭＡＰＰ）对木纤维进行接枝处理。通过红外光谱分析,证明了马来酸酐接枝聚丙烯和木纤维之间产生了酯化反应,提出了木纤维和聚丙烯基体的粘合性。通过扫描电镜（ＳＥＭ）的观察及示差扫描量热计（ＤＳＣ）的分析,证明了接枝木纤维比未接枝的木纤维与聚丙烯基体间的界面相容性有了明显的改善,使木纤维能均匀地分散在聚丙烯基体中,从而提高了复合材料的加工性能和力     

Study on effect of polydimethylsiloxane in intumescent flame retardant polypropylene

The effect of polydimethylsiloxane (PDMS) in intumescent flame retarded polypropylene (PP) containing melamine phosphate (MP) was studied using limiting oxygen index (LOI), UL-94 test, thermogravimetric analysis (TG), real time Fourier transform infrared (FTIR) and pyrolysis/gas chromatogram/mass spectrometry (Py–GC/MS). It was found that the addition of PDMS into the PP/MP composites leads to a decrease in the LOI values of the PP/MP/PDMS composites, and the values increase gradually with the increase of the PDMS content. The UL-94 test results indicate that the PP/MP/PDMS composite with 30% PDMS reaches the V-0 rating compared with no rating of the PP/MP composite at the same MP loading. The water resistance of the PP/MP/PDMS composites was investigated, and the improved water leaching of MP was observed. The TG and RTFTIR results illustrate the thermal stability of the PP/MP composites containing PDMS is improved. Moreover, the pyrolysis of the PP/MP/PDMS composites was studied by the Py–GC/MS method.     

增容剂对PP/PET原位微纤化共混物的影响

通过"熔融挤出-热拉伸-淬冷"的方法制备了原位微纤化共混物。采用扫描电镜、差示扫描量热仪和力学性能测试等方法研究了增容剂PP-g-GMA含量对共混物微观形态、力学性能和结晶性能的影响。结果表明,增容剂的加入可明显提高两相相容性,改善界面效果,明显降低拉伸前初始粒子的尺寸,但同时使拉伸后形成的微纤呈现一定的损坏,长径比有所降低。增容剂可以明显改善微纤化共混物力学性能,当其含量为2 %（质量分数,下同）时拉伸强度比未增容试样提高了11.0 %,弯曲强度都提高了11.3 %;当其含量为6 %时冲击强度也比未增容共混物提高了34.5 %。此外,PET微纤对PP有很好的异相成核作用,使其结晶温度提高了16.3 ℃,结晶时间为纯PP的32 %左右,而增容剂的加入使共混物中PP的结晶时间延长。     

山梨糖醇类及有机磷酸盐类成核剂对聚丙烯性能的影响

利用力学性能测试、偏光显微镜、光电雾度仪及差热分析仪分别考察了山梨糖醇类成核剂(TM-3)和有机磷酸盐类成核剂(NA-21)对聚丙烯(PP)透明性、结晶性能及力学性能的影响。结果表明:NA-21和TM-3对PP均有明显增透的作用;NA-21比TM-3更能提高PP的结晶温度,而TM-3比NA-21更能提高PP的结晶度;TM-3的加入能明显提高PP的冲击强度,而NA-21的加入能明显提高PP的拉伸强度。     

硅灰石在聚丙烯塑料改性方面的应用研究

通过硅烷改性剂表面处理的针状硅灰石可提高硅灰石疏水亲有机性,改善硅灰石在聚丙烯树脂中的分散性。填充后的聚丙烯材料在拉伸强度、弯曲强度、弹性模量以及弯曲模量等方面的性能有所提高,而在韧性方面有略微降低。同时材料的耐温性得到较大提高。     

Ti/SnO_2+Sb_2O_4+GF/PbO_X电极的制备及电催化性能研究

采用热分解和电沉积相结合方法制备了Ti/SnO2＋Sb2O4＋GF/PbOX电极,采用三电极体系测定了上述电极在不同溶液中的循环伏安曲线,同时利用循环伏安曲线求得了电极表面的分形维数、活化能和动力学参数等。结果表明该电极电催化性能优于传统电极,是一种优良的电催化剂。     

聚丙烯透明剂的合成研究及应用

以山梨醇和二(三)甲基苯甲醛为原料,在酸催化下进行醇醛缩合反应,合成了多甲基苄叉山梨醇二缩醛(简称CT),并对影响产品收率的因素和CT对聚丙烯性能的影响进行了考察.CT能显著降低聚丙烯雾度(≤15%),提高光泽度(≥130%).     

Characterising the time-dependant behaviour on the single fibre level of SHCC: Part 2: The rate effects on fibre pull-out tests

This paper is the second part of a two paper series about the time-dependant behaviour of Strain Hardening Cement-based Composite (SHCC) on the single fibre level. Having dealt with mechanisms of creep in SHCC in the first part, this paper reports single fibre pull-out tests that were done to investigate the effect of the pull-out rate on the mechanical response of the interface between the fibre and the matrix. It was found that not only the pull-out resistance increased with an increase of the pull-out rate but the probability of fibre rupture during pull-out as well. Another important finding was that the interfacial shear resistance and slip-hardening coefficient are not only dependant on the pull-out rate, but also the embedment length.     

Synergistic effects of hydroxy silicone oil on intumescent flame retardant polypropylene system

The effects of hydroxy silicone oil as a synergistic agent on the flame retardancy of intumescent flame retardant polypropylene composites (IFR-PP) were studied, and the IFR system mainly consisted of the ammonium polyphosphate (APP), melamine (MEL) and pentaerythritol (PER). The UL 94 rating, thermogravimetric analysis (TGA), cone calorimeter (CONE) and digital photograph were used to evaluate the synergistic effects of hydroxy silicone oil (HSO). It has been found that the PP composite containing only APP, MEL and PER does not show good flame retardancy at 30% additive level. The cone calorimeter results show that the heat release rate, mass loss rate, mass, total heat release, carbon monoxide and carbon dioxide of PP/APP/MEL/PER/HSO composites decrease in comparison with the PP/APP/MEL/PER composite. The digital photographs demonstrated that HSO could promote to form the homogenous and compact intumescent char layer. Thus, a suitable amount of HSO plays a synergistic effect in the flame retardancy.