滑石粉填充PP复合材料的耐候改性研究

以自制的耐候母粒对滑石粉填充聚丙烯(PP)进行耐候改性,并对制得的PP复合材料的人工加速老化行为进行了测试和评价。结果表明,经氙灯人工加速老化2000h后,经耐候改性的滑石粉填充PP复合材料的拉伸强度、断裂伸长率和悬臂梁缺口冲击强度保持率分别达到99%、55%和83%,灰卡评级达到4级,表现出优异的耐候性能。     

聚丙烯高强丝防老化母粒的研制和应用

：将加入了防老化母粒的聚丙烯高强丝进行人工加速老化试验和户外大气暴露试验,讨论了防老化母粒在高强丝上的应用。结果表明：添加２％的防老化母粒,经１年的户外大气暴露试验,聚丙烯高强丝的断裂强度保持率高达８０．２％,断裂伸长保持率达７９．０％;而未加防老化母粒的聚丙烯高强丝,户外暴露５个月,断裂强度保持率降至４６．７％,断裂伸长保持率降至３６．４％。同时还对添加防老化母粒与使用耐候级聚丙烯专用料的耐候性、不同母粒添加量的耐候性做了对比。     

聚甲醛的耐候改性及其光稳定性研究

以受阻胺光稳定剂和紫外线吸收剂对聚甲醛(POM)进行光稳定化耐候改性,并对制得的耐候POM的力学性能和人工加速老化行为进行了测试和评价。结果表明,经氙灯人工加速老化1000h后,试样的拉伸强度保持率、断裂伸长率保持率和缺口冲击强度保持率分别达到103%、76.2%和84.4%,色差由7.6减小至0.8,远优于未经光稳定化处理的POM的相应性能。     

提高微孔聚氨酯弹性体抗紫外光老化性能的研究

分析了微孔聚氨酯弹性体材料在日光照射下发生光老化的原因。考察了抗氧剂264（BHT）、紫外线吸收剂UV－531、UV－9、UV－P对提高材料抗光老化性能的影响，实验结果表明，BHT与UV－P并同时材料具有良好的光稳定性，机械性能保持率较高。     

熔融沉积成型PLA/麦秸粉复合材料的抗老化性能

采用木塑复合材料与熔融沉积成型技术相结合制备了聚乳酸(PLA)/麦秸粉复合材料,利用扫描电子显微镜、傅里叶变换红外光谱、X射线光电子能谱对复合材料进行测试,分析了紫外光吸收剂UV531对复合材料抗老化性能的影响。结果表明:老化使复合材料变白褪色,添加UV531可改善颜色变化;老化使复合材料的力学性能下降,适量的UV531可提高复合材料的力学强度保持率,w(UV531)为0.6%时,弯曲强度保持率、冲击强度保持率达最大,分别为96.11%,89.03%;老化使复合材料的表面出现裂纹,UV531可以减小裂纹的长度与宽度;老化使复合材料表面被氧化,O原子与C原子个数的百分比增加,UV531可以降低材料被氧化的程度;老化使复合材料的表面官能团发生变化,UV531可以适当抑制该变化。     

ABS/PVC合金耐候性能的研究

通过一年的自然大气曝露试验和1000小时氙灯人工加速老化试验,对经稳定的ABS、ABS/PVC合金、耐候ASA老化前后的颜色变化和悬臂梁缺口冲击强度保持率进行比较,可以得出结论:ABS/PVC合金的耐候性能与经稳定ABS相比有大幅度提高;在一定时间内,颜色稳定性和悬臂梁缺口冲击强度保持率与ASA相近。     

聚甲醛的耐紫外光/耐候改性

研究了紫外光吸收剂、热稳定剂、光稳定剂等复合助剂对聚甲醛(POM)耐候性能的影响,并对改性前后的POM进行了人工加速老化测试和评价。结果表明:经人工加速老化500,1 000 h后,改性POM的拉伸强度、弯曲强度、悬臂梁缺口冲击强度保持率分别达到104.0%和106.0%,106.0%和107.0%,68.9%和62.2%;老化前后改性POM颜色基本没有变化,远优于未经耐候改性POM的相应性能。     

聚乙烯耐候母粒的制备及其在聚乙烯薄膜中的应用

采用氙灯人工加速老化的方法,研究了光稳定剂、光吸收剂及光引发剂等对PE薄膜耐候性能的影响。结果表明:光稳定剂944和327可改善PE薄膜的耐候性能,但是长效效果较差,由光吸收剂2#制备的耐候母粒对PE薄膜具有很好的长效耐候效果,且不添加光引发剂的效果更好,氙灯老化3000h后,拉伸强度保持率可达75%。     

高韧耐候改性聚甲醛性能研究

将热塑性聚氨酯(TPU)、抗氧剂、紫外光吸收剂、光稳定剂、甲醛吸收剂、润滑剂、晶核剂等助剂与聚甲醛(POM)进行共混制备了高韧耐候改性POM,分析了紫外光老化实验后POM的力学性能变化、光稳定性以及色差等。研究表明,经1000 h紫外光老化后,高韧耐候改性POM的力学性能、光稳定性及色差得到明显改善。其中拉伸强度、弯曲强度、拉伸弹性模量保持率较好,分别达到106.9%,109.1%,106.6%;缺口冲击强度及断裂伸长率保持率明显提高,分别达到75.0%和104.5%;质量损失为–0.068%,光稳定性较好;灰卡评级为4–5,色差基本没有变化,韧性和耐候性能都达到了预期效果。     

涂料和涂膜的检验、分析及评价

200901134 用玻璃微球改性的环氧涂料的腐蚀磨损动力学；200901135 有机涂层加速耐候试验和考虑了气象数据的天然耐候试验对比；200901136 UV老化对防腐涂层电化学性能的影响；200901137聚合物水泥防水涂料拉伸强度测量的不确定度分析。     

紫外光对PP蠕变行为的影响

通过对聚丙烯(PP)施加紫外光的方法研究了紫外光对其蠕变行为的影响,利用蠕变性能测试、GPC、XPS、PALS、SEM等手段考察了紫外光作用下的PP蠕变行为及其失效机理。实验结果表明:紫外光能加速PP的蠕变失效,其失效机理与辐照强度有关;短时间失效主要是由紫外光引起的分子链段的活性变化所致,长时间作用下的失效,主要是紫外光引起的老化导致材料强度的削弱所致;另外,对不同种类的PP,在相同的外部条件(下温度、应力和紫外光,)其失效速率与结构和分子量无关,只与该温度下材料的屈服强度有关,屈服强度越高抗,蠕变能力越好。     

自制光稳定剂HWPAN-g-TiO2与几种光稳定剂对聚丙烯性能的对比研究

利用废旧腈纶织物制备了一种聚丙烯（PP）用大分子紫外屏蔽吸收类型光稳定剂,利用其和通用的受阻酚类光稳定剂分别制备耐候性PP复合材料,并进行了人工加速老化实验。探究了大分子紫外屏蔽吸收类型光稳定剂在PP老化过程中对PP老化降解的影响,并与通用的受阻酚类光稳定剂进行了对比研究。结果表明,大分子紫外屏蔽吸收类型光稳定剂效果明显,在人工加速老化500 h之后,PP的羰基指数高达150.3;而PP/HWPAN-g-TiO2仅为53,与此同时,PP的拉伸强度从25 MPa降至6.9 MPa,下降了72.4 %;而PP/HWPAN-g-TiO2的拉伸强度从29 MPa降至25 MPa,下降13.8 %。     

Adhesion Improvement by UV Grafting onto Polyolefin Surfaces

High Density Poly(ethylene) (HDPE) and Poly(propylene) (PP) were subjected to several surface treatments, namely UV grafting of hydroxyethylmethacrylate (HEMA), plasma deposition of HEMA and oxygen plasma treatment. Treated surfaces were subjected to two post-treatment routines (extraction with ethanol and high temperature aging). The effect of these treatments on the adhesion of HDPE and PP to epoxy coated studs was evaluated by a pull test. No adhesion at all was recorded on untreated samples. On the other hand, all the treatments yield high bond strength in the case of HDPE: an average bond strength of about 290 kg/cm² and of about 200 kg/cm² was observed after UV grafting and plasma treatments. The treated samples were practically insensitive to post-treatments. As to PP, which undergoes chain scission in plasma, it is best treated by the comparatively milder conditions of UV grafting, which yields an average bond strength similar to that observed on HDPE. O₂ and HEMA-plasma-treated PP show a mean bond strength close to 50 kg/cm², and are deeply affected by the post-treatment routines.     

PP及PP/EPDM共混物室内外老化行为的研究

通过中国西部3个地区（新疆尉犁、西藏拉萨和四川成都）室外自然老化和室内加速老化（热氧、紫外老化）的对比,研究了聚丙烯及聚丙烯/三元乙丙橡胶（PP/EPDM）共混物室内外老化前后力学性能的变化和表面微观形态的变化,以及其室内外老化的对应关系。结果表明,室外老化初期PP的拉伸强度提高,老化中后期随着降解程度加剧拉伸强度下降;EPDM的加入提高了PP的耐老化性能,其中成都地区老化试样最为明显,24个月后拉伸强度保持率高达115 %;PP和PP/EPDM共混物室内热氧老化后拉伸强度变化不大,紫外老化后拉伸强度则呈现下降趋势;综合考虑热氧和紫外老化,通过时间等效关系可以更好地联系室内外老化,为预测材料在自然状态下的服役寿命奠定了基础。     

Adhesion Improvement by UV Grafting onto Polyolefin Surfaces

High Density Poly(ethylene) (HDPE) and Poly(propylene) (PP) were subjected to several surface treatments, namely UV grafting of hydroxyethylmethacrylate (HEMA), plasma deposition of HEMA and oxygen plasma treatment. Treated surfaces were subjected to two post-treatment routines (extraction with ethanol and high temperature aging). The effect of these treatments on the adhesion of HDPE and PP to epoxy coated studs was evaluated by a pull test. No adhesion at all was recorded on untreated samples. On the other hand, all the treatments yield high bond strength in the case of HDPE: an average bond strength of about 290 kg/cm² and of about 200 kg/cm² was observed after UV grafting and plasma treatments. The treated samples were practically insensitive to post-treatments. As to PP, which undergoes chain scission in plasma, it is best treated by the comparatively milder conditions of UV grafting, which yields an average bond strength similar to that observed on HDPE. O₂ and HEMA-plasma-treated PP show a mean bond strength close to 50 kg/cm², and are deeply affected by the post-treatment routines.     

A study on the photo-degradation of zinc oxide (ZnO) filled polypropylene nanocomposites

This research aims to study the photo-degradation characteristics for zinc oxide (ZnO) nanoparticle filled polypropylene (PP) nanocomposites. By paying attention to the evolution of the carbonyl absorption bands from FTIR analysis, it has been observed that UV irradiation induced significant photo-degradation for unfilled PP. However, with the incorporation of ZnO nanoparticles into the PP matrix, the extent of photo-degradation was significantly reduced. This is due to the superior UV light screening effects offered by the ZnO nanoparticles. WAXD measurements showed that β-form PP crystal had been induced in the PP/ZnO nanocomposites. An interesting observation from this study is that β-form PP crystal was also induced in unfilled PP due to UV irradiation. UV-irradiation induced degradation caused a significant drop in the ductility for unfilled PP. With the incorporation of ZnO nanoparticles, the ductility, and hence the tensile strength were recovered to some extent. The higher the ZnO particle content, the higher the elongation at break value in the UV irradiation treated nanocomposites. It was also observed that surface cracks were induced by photo-degradation, and the Talysurf surface profile measurements indicate that the severity of the surface cracks were significantly reduced in the ZnO/PP nanocomposites.     

Polypropylene/carbon nanotube composites prepared with a environmentally benign processes

Polypropylene (PP)/multiwalled carbon nanotube (MWNT) composites were prepared with an environmentally benign processes. The surface functionalization of the MWNTs was performed with water as a solvent, and the functionalized MWNTs were mixed with PP to form composites with a melt process. The effects of the MWNTs on the mechanical and thermal properties of the composites were studied. The tensile strength and modulus of the composites increased with the amount of MWNTs. The thermal stability was also improved by the reinforced MWNTs. The MWNTs also improved the oxidative stability of the composite on UV irradiation. Although pure PP degraded almost completely after 12 h of irradiation, the composite reinforced with MWNTs retained some level of mechanical strength after UV irradiation. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Improved Ultraviolet (UV) Radiation Stability of the Polypropylene (PP) Films of Woven Jumbo Bags for Outdoor Applications

Several formulations were developed with polypropylene (PP) in combination with antioxidants, calcium stearate, hindered amine light stabilizers (HALS) and ultraviolet light absorber (UVA) for making woven jumbo bags, which will be capable of carrying a load of two tons of materials in outdoor conditions. Thin films of these formulations were extruded followed by stretching to improve mechanical properties. Both stretched and un-stretched PP films were subjected to severe accelerated weathering by ultraviolet (UV) radiation for various periods and it was observed that un-stretched films reached 50% retention of tensile strength (TS) within 500 hours of exposure, while stretched films (tapes) did not reach 50% TS retention even after 10,500 hours of the exposure indicating an improved UV stability of the stretched films of PP.     

Effect of Ultraviolet Radiation on the Mechanical and Dielectric Properties of Hessian Cloth/PP Composites with Starch

Hessian cloth (jute fabrics) reinforced poly(propylene) (PP) composites (45 wt% fiber) were prepared by compression molding and the mechanical properties were evaluated. Jute fabrics and PP sheets were treated with UV radiation at different intensities and then composites were fabricated. It was found that mechanical properties of the irradiated jute and irradiated PP-based composites were found to increase significantly compared to that of the untreated counterparts. Irradiated jute fabrics were also treated with aqueous starch solution (1–5%, w/w) for 2–10 min. Composites made of 3% starch-treated jute fabrics (5 min soaking time) and irradiated PP showed the best mechanical properties. Tensile strength, bending strength, tensile modulus, bending modulus and impact strength of the composites were found to improve 31, 41, 42, 46 and 84% higher over untreated composites. Water uptake, thermal degradation and dielectric properties of the resulting composites were also performed.     

Evaluation of interactions between compatibilizers and photostabilizers in coir fiber reinforced polypropylene composites

Coir fiber‐reinforced polypropylene composites (PP/CF), compatibilized with maleic anhydride grafted polypropylene (PPMAH) and stabilized with a hindered amine, HALS (Tinuvin^® 791) and UV absorber (Hostavin^® ARO 8), were prepared in a co‐rotating twin‐screw extruder. The effects of additives and their interactions were investigated by analyzing the mechanical properties, in tensile strength, scanning electron microscopy (SEM) and Differential Scanning Calorimetry (DSC). The results indicate that the incorporation of coir, in the presence of the compatibilizer, significantly increases tensile strength, but in the absence of the compatibilizer, the natural fibers act as stress concentrators, allowing a lower tensile strength to the sample. The joint presence of Tinuvin^® and the compatibilizer has a negative effect on tensile strength and on the compatibility of the natural fiber with the matrix. UV absorber does not affect the compatibility of the PP/CF composites. POLYM. ENG. SCI., 57:1179–1185, 2017. © 2017 Society of Plastics Engineers