聚丙烯塑料表面低温碱性化学镀Ni-P合金

为了克服塑料表面酸性高温化学镀Ni-P合金工艺的局限性,研究了中低温碱性镀液中聚丙烯（PP）塑料表面化学镀Ni-P合金的工艺。采用扫描电镜（SEM）表征了镀层的表面形貌,用能谱（EDS）分析了镀层成分,用X射线衍射研究了镀层的相结构。结果表明,最佳工艺配方及参数：基材在350g／L CrO3,200mL／L 98％ H...     

蒙脱土对膨胀型阻燃聚丙烯的性能影响

本文以IFR为阻燃剂,蒙脱土为协效剂,MAH—g—PP为相容剂对聚丙烯进行阻燃改性。研究了阻燃剂和协效剂对聚丙烯燃烧性能、力学性能和加工性能的影响,并运用热重分析（TGA）和差热分析（DTA）表征了阻燃聚丙烯的热分解过程,结果表明：     

石墨烯微片/聚丙烯导热复合材料的制备与性能

通过熔融共混法制备了两种不同型号石墨烯微片（GNPs）填加的GNPs/聚丙烯（PP）导热复合材料,研究了GNPs型号（KNG180,KNG150）和含量对其导热性能、密度、结晶性能和热稳定性能的影响。结果表明,KNG180 GNPs/PP复合材料密度高于KNG150 GNPs/PP,同时KNG180对提高聚丙烯结晶度的效果优于KNG150。随着石墨烯微片含量的增加,两种复合材料导热系数均明显增大,而且KNG180填充的复合材料导热性能明显优于KNG150;当KNG180的添加量为60%（质量分数）时,GNPs/PP复合材料的导热系数从纯聚丙烯的0.087 W/（m·K）提高到1.32 W/（m·K）,提高了14倍多。石墨烯微片的加入显著提高了聚丙烯的热稳定性,当KNG180或KNG150的质量分数为10%时,聚丙烯达到最大热失重速率时的温度从345.1 ℃分别提高到374.6 ℃和397.9 ℃,但是当石墨烯微片超过一定含量时,热稳定性会下降。     

再生食品级聚丙烯一现实吗？

据英国废物和资源工作组（WRAP）专家PaulDavidson说，聚丙烯（PP）废品有可能通过回收再生成食品级塑料。     

结晶结构对聚丙烯光致发光性能的影响

研究了等规聚丙烯结晶结构对其发光性能的影响，由同一材料出发制备了α－聚丙烯（α－PP）、β-聚丙烯（β－PP）和次晶聚丙烯（S－PP）3种结晶结构，并测定了其紫外荧光性能。结果表明聚集态结构对发光影响很很大，β-PP发光最强，β结晶有利于发光。     

聚丙烯塑料食品接触材料中再生料的鉴别探析

对常用的食品接触材料聚丙烯（PP）制品中,再生料的鉴别进行了探析。首先,采用傅里叶变换红外光谱（FTIR）、差示扫描量热（DSC）和热失重分析（TGA）法对样品的组成、结构和热性能进行对比分析,筛选异常数据。利用场发射扫描电子显微镜（SEM）和能谱仪（EDS）相结合的技术对样品的形貌和元素组成进行分析,从微观组成形貌对样品进行精确分析。进一步对筛选出的样品进行荧光增白剂、重金属、增塑剂等有害物质的含量和迁移进行测试研究。研究结果表明,待测样品中的1#样品为PP材质,但热性能不佳,其基体中无其他杂质,未检出重金属和荧光增白剂有害物质,备受关注的邻苯二甲酸酯类增塑剂的检测结果也达标。     

苯甲酸功能化石墨烯-Al(OH)3协同阻燃聚丙烯

以氧化石墨（GO）为原料,制备了苯甲酸功能化石墨烯（BFG）,采用IR和XRD对BFG结构进行了表征。再将BFG作为阻燃协效剂添加到Al（OH）₃/聚丙烯（PP）中,研究不同质量比的BFG与Al（OH）₃对PP材料阻燃和力学性能的影响。通过对阻燃BFG-Al（OH）₃/PP复合材料进行极限氧指数（LOI）测试、热失重分析、锥形量热分析、拉伸测试及残炭SEM分析,考察BFG-Al（OH）₃/PP复合材料的阻燃性能和力学性能。研究结果表明,与其他阻燃PP相比,1.5wt% BFG-38.5wt% Al（OH）₃/PP的阻燃和力学性能最佳,LOI可达到24.6%,拉伸强度为20.64 MPa,且其热释放速率峰值和总热释放量比纯PP分别降低了51.5%和18.6%。     

环保型无卤阻燃聚丙烯的研制

目前一些发达国家已开始禁止使用含各种卤素阻燃剂的塑料制品。随着我国环保标准的提高，减少使用或不使用卤素阻燃剂必将成为塑料行业的趋势，因此研制无卤、低烟的环堡型阻燃聚丙烯（PP）有着十分重要的现实意义。江苏技术师范学院应用材料研究所周健采用几种不同类型的无卤阻燃剂研制环保型阻燃聚丙烯（PP）。结果表明，Mg（OH）2复合阻燃体系和氮磷复合阻燃体系对PP均有良好的阻燃效果；研制的Mg（OH）2复合阻燃PP具有良好的阻燃性能和力学性能，并具有实际应用价值。     

不同氟化改性方法对孔洞聚丙烯膜电荷存储特性的影响

研究了氢氟酸（HF）、氟气（F2）和二氟化氙（XeF2）对孔洞聚丙烯（PP）膜的氟化改性及氟化改性对其驻极性能的影响。红外光谱分析结果表明：3种方法均能有效地实现PP膜的氟化；热刺激放电（TSD）电流和原位实时电荷等温衰减的测量结果进一步表明：氟化孔洞PP驻极体膜的电荷热稳定性较原膜得到显著的改善。另外，PP膜的预氧化不仅为随后的HF氟化所必需，对F2和XeF2的氟化也具有显著的促进作用，XeF2与PP膜的反应起始温度约为60℃。     

膨胀石墨/氧化镍成炭剂对聚丙烯的催化阻燃

从催化及成炭阻燃的角度出发,提出了一种新的聚丙烯（PP）催化成炭剂（酸洗膨胀石墨（SXGO）/氧化镍（Ni2O3））。阻燃测试结果表明,Ni2O3与SXGO协同催化剂在聚丙烯燃烧过程中加速聚合物脱氢,推进降解产物的芳构化和残炭的形成,当聚丙烯材料组成为PP/SXGO/Ni2O3（92/3/5）时,聚丙烯材料的成炭率最高...     

Dimensional stability and mechanical behaviour of wood–plastic composites based on recycled and virgin high-density polyethylene (HDPE)

This paper investigated the stability, mechanical properties, and the microstructure of wood–plastic composites, which were made using either recycled or virgin high-density polyethylene (HDPE) with wood flour (Pinus radiata) as filler. The post-consumer HDPE was collected from plastics recycling plant and sawdust was obtained from a local sawmill. Composite panels were made from recycled HDPE through hot-press moulding exhibited excellent dimensional stability as compared to that made from virgin HDPE. The tensile and flexural properties of the composites based on recycled HDPE were equivalent to those based on virgin HDPE. Adding maleated polypropylene (MAPP) by 3–5 wt% in the composite formulation significantly improved both the stability and mechanical properties. Microstructure analysis of the fractured surfaces of MAPP modified composites confirmed improved interfacial bonding. Dimensional stability and strength properties of the composites can be improved by increasing the polymer content or by addition of coupling agent. This project has shown that the composites treated with coupling agents will be desirable as building materials due to their improved stability and strength properties.     

Application of a computer model to evaluate the ability of plastics to act as functional barriers

A simulation model computer program, which accounts for not only the diffusion process inside the polymer but also partitioning of the contaminant between the polymer and the contacting phase, was developed based on a numerical treatment, the finite element method, to quantify migration through multilayer structures. The accuracy of the model in predicting migration was demonstrated successfully by comparing simulated results to experimental data. For this study, three‐layer co‐extruded high density polyethylene (HDPE) film samples, having a symmetrical structure with a contaminated core layer and virgin outer layers as the functional barriers, were fabricated with varying thickness of the outer layers and with a known amount of selected contaminant simulant, 3,5‐di‐t‐butyl‐4‐hydroxytoluene (BHT), in the core layer. Migration of the contaminant simulant from the core layer to the liquid food simulants was determined experimentally as a function of the thickness of the outer layer at different temperatures. The computer program, developed as a total solution package for migration problems, can be applied not only to multilayer structures made with the same type of plastics but also to structures with different plastics, e.g. PP/PE/PP. This work might provide the potential for wider use of recycled plastic, especially polyolefins, which have lower barrier properties, in food packaging, and simplification of the task of convincing the FDA that adequate safety guarantees have been provided. Copyright © 2003 John Wiley & Sons, Ltd.     

Melt blend studies of nanoclay-filled polypropylene (PP)–high-density polyethylene (HDPE) composites

The objective of this work is to study how the rheological factors of unfilled and nanoclay-filled HDPE–PP blend series influence the structure, morphology, and mixing characteristics. For this study, a series of HDPE–PP blends (0–100 wt % HDPE), with and without nanoclay, was prepared by using melt-mixing method. Nanoclay was varied from 0 to 5 wt % in all the blend and polymer series. The rheological properties were examined by melt viscosity, scanning electron microscopy, and theory of mixing. The result indicated that the viscosity of the blend increased as HDPE and nanoclay content increased, and also affected the structure and morphology of the resulting blend. The thermal properties were examined by using differential scanning calorimetry and suggest improved crystalline and melting characteristics of PP and PP-rich phase of blend. The structure of nanoclay-filled blend was examined by X-ray diffraction and transmission electron microscopy, confirming the formation of nanocomposite with improved tensile properties.     

基于塑料近红外光谱的判别分类研究

目的 为了回收可用于不同物品包装的塑料,对不同塑料种类进行识别分类。方法 首先采集PP、PET、HDPE、TPE、PLA、PBT、TPU、POM-M90、PPO-GF20NC、TPB、PPS、ABS、PPO(natural)、SAN、POM-F20、PPO(white)16种塑料的近红外光谱数据,其次针对光谱数据采集时存在的噪声问题,使用SG平滑滤波进行了光谱数据预处理,之后利用主成分分析算法进行光谱数据降维,减少待处理数据量,最后分别运用无监督聚类K-means算法和监督聚类极大似然估计、Fisher判别式以及光谱角算法建立4类分类模型。结果 K-means算法可以将PPO-GF20N、PLA和PPO(本色)与其他塑料粒子区分开,准确率分别是100%、100%以及80%;Fisher判别式和极大似然估计法对POM-M90和POM-F20的识别准确率为93%,其他塑料粒子识别准确率均为100%;光谱角算法对PET的识别准确率为80%,POM-F20的识别准确率为47%,其余粒子的识别准确率均大于90%。结论 上述机器学习算法结合近红外光谱成像技术建立分类模型可为常见塑料的鉴别研究提供参考。     

Elastomer modified polypropylene–polyethylene blends as matrices for wood flour–plastic composites

Blends of polyethylene (PE) and polypropylene (PP) could potentially be used as matrices for wood–plastic composites (WPCs). The mechanical performance and morphology of both the unfilled blends and wood-filled composites with various elastomers and coupling agents were investigated. Blending of the plastics resulted in either small domains of the minor phase in a matrix of major phase or a co-continuous morphology if equal amounts of HDPE and PP were added. The tensile moduli and yield properties of the blends were clearly proportional to the relative amounts of HDPE and PP in the blends. However, the nominal strain at break and the notched Izod impact energies of HDPE were greatly reduced by adding as little as 25% of the PP. Adding an ethylene–propylene–diene (EPDM) elastomer to the blends, reduced moduli and strength but increased elongational properties and impact energies, especially in HDPE-rich blends. Adding wood flour to the blends stiffened but embrittled them, especially the tougher, HDPE-rich blends, though the reductions in performance could be offset somewhat by adding elastomers and coupling agents or a combination of both.     

Chemical recycling of plastic wastes made from polyethylene (LDPE and HDPE) and polypropylene (PP)

The recycling of either model polymers or waste products based on low-density polyethylene (LDPE), high-density polyethylene (HDPE) or polypropylene (PP) is examined using the dissolution/reprecipitation method, as well as pyrolysis. In the first technique, different solvents/non-solvents were examined at different weight percent amounts and temperatures using as raw material both model polymers and commercial products (packaging film, bags, pipes, food-retail outlets). The recovery of polymer in every case was greater than 90%. FT-IR spectra and tensile mechanical properties of the samples before and after recycling were measured. Furthermore, catalytic pyrolysis was carried out in a laboratory fixed bed reactor with an FCC catalyst using again model polymers and waste products as raw materials. Analysis of the derived gases and oils showed that pyrolysis gave a mainly aliphatic composition consisting of a series of hydrocarbons (alkanes and alkenes), with a great potential to be recycled back into the petrochemical industry as a feedstock for the production of new plastics or refined fuels.     

Effects of gamma irradiation on polypropylene, polypropylene + high density polyethylene and polypropylene + high density polyethylene + wood flour

The effect of the gamma-irradiation on the mechanical properties of the composites, Polypropylene (PP), PP+high density Polyethylene (HDPE), PP+ HDPE+wood flour, where HDPE is virgin and recycled, was studied. This paper discusses the behavior of the composites after exposure to various doses of gamma irradiation (1–7 MRads) in the presence of oxygen. The dependence of mechanical properties on the integral dose for a constant dose rate of 0.48 MRads/h confirms the influence of the irradiation. Strong effects on the elongation at break and break strength is noticed. The mathematical analysis suggests for the PP+r-HDPE a bimolecular process of the elongation at break. On the order hand, for the PP+HDPE a complex process is represented for a three exponential equation. Received: 9 October 2000 / Reviewed and accepted: 10 October 2000     

Performance of recycled plastic waste modified asphalt binder in Saudi Arabia

The amount of solid plastic waste generated from material packages like plastic bottle and similar utilities within the kingdom of Saudi Arabia has skyrocketed. This is as a result of the increased level of industrial packaging due to rapid industrialisation and fast urbanisation in the country. The associated cost of managing these solid wastes has also multiplied as the task become difficult and enormous. The effect of polypropylene, high- and low-density polyethylene (PP, HDPE and LDPE)-recycled plastic wastes (RPW) on the viscoelastic performance of the local asphalt binder has been investigated. The recycled plastics were obtained by shredding and grounding the RPW to a desirable size for easier blending with the asphalt binder. All the RPWs result in an improved rutting performance. The RPW-modified asphalts upper PG limit increase by at least one level for each 2% increase in the RPW content, in most cases. An increase of 55, 19 and 9% in resilient modulus (M_R) was observed for PP-, HDPE- and LDPE-produced asphalt concrete (AC), respectively. Correlation between the M_R of the AC and non-recoverable creep compliance (J_nr) of the asphalt binder was established. The obtained viscoelastic properties of the RPW-modified binder was utilised to model a typical pavement section using AASHTO mechanistic empirical pavement design guide (ME-PDG) software. The predicted distresses of the modelled pavement shows significant rutting and fatigue performance improvement for pavement produced with the RPW. Elastomeric type of polymer is required to supplement these RPW to enable them meet the AASHTO TP 70 elastic recovery requirement.     

Improvement of mechanical properties of recycled plastic blends via optimizing processing parameters using the Taguchi method and principal component analysis

In this paper, the Taguchi method and principal component analysis (PCA) are used to improve the mechanical properties of recycled polypropylene (PP) blends in injection moulding procedure, with detailed assessments performed on each method and comparison was made based on results of both the methods. The experimental design was carried out by adopting a L9-3⁴ Taguchi orthodoxy array (OA), which has four controllable factors (i.e., melt temperature, mould temperature, injection speed and packing pressure) at three levels. Injection moulded specimens made from different compositions of virgin-recycled PP were tested to determine the optimal conditions for the injection moulding procedure. The effects of the processing parameters and the proportion of recycled plastic in composites on the mechanical properties were investigated, the optimal conditions for desired properties were obtained and then verified. The appropriate blending ratio of virgin and recycled plastic was evaluated. The results reveal that deteriorations in the mechanical properties of products produced from recycled plastic can be improved by optimizing the processing parameters during the injection moulding procedure.     

High density polyethylene and poly(ethylene terephthalate) in situ sub-micro-fibril blends as a matrix for wood plastic composites

Wood plastic composites were prepared based on in situ formed poly(ethylene terephthalate) (PET) sub-micro-fibril reinforced high density polyethylene (HDPE) matrices, using a two-step reactive extrusion technology. The use of ethylene-glycidyl methacrylate (E-GMA) copolymer improved phase compatibility in the sub-micro-fibril blends (SMFBs) with 75% HDPE and 25% PET. Most of in situ formed PET fibrils were less than 500 nm in diameter. The PET fibrils obviously increased mechanical properties of the blend, especially the moduli. The subsequent addition of 40 wt.% wood flour did not influence the size and morphology of PET fibrils, and the fibrils and wood fibers had a synergic reinforcement effect on composite properties. Compared with the HDPE/wood composites, the SMFB/wood system had 65% higher tensile strength, 95% higher tensile modulus, 42% higher flexural strength, and 64% higher flexural modulus, respectively. The technology offers a way to use engineering plastics (i.e., PET) for high performance WPC manufacturing.