A recycled packaging material was found to be a PP copolymer after examinations with DSC, FTIR, and TG techniques. It produced 4.39% residue when heated to 800 °C. In addition, SEM microscopic observations revealed some particles dispersed in the recycled PP (recPP) matrix, resulting in a great source for promotion of recPP crystallization temperature. In the present work, NPG, TMB-5, and CaPA were used as β-nucleating agents to modify PP and recPP crystallization behaviors. The results imply that these three nucleating agents are effective for PP to form β crystal in which TMB-5 revealed the best induction and heterogeneous nucleation effects. However, the nucleating effect for NPG decreased when it was added to recPP. The effect of CaPA also weakened, whereas TMB-5 performed well with the optimum content of 0.1%. When CaPA was added together with PCB powder, the β-nucleating effect of CaPA was enhanced, making β crystal as the main form when using only 0.01% CaPA.

本研究使用熔融共混挤出法,制备了改性玻璃纤维/聚丙烯复合材料,利用差式扫描量热仪对复合材料的结晶熔融行为进行了探究,同时测试了各材料的冲击强度.结果表明,利用混合稀酸刻蚀后的玻纤,不但具有异相成核作用,提高结晶峰温,而且具有β晶诱导作用,使冲击性能提高.经庚二酸钙表面修饰后,β晶诱导和异相成核效应更强,β晶成主要晶型,进一步改善了复合材料的冲击性能.

After separation of metals from printed circuit boards (PCBs), they are sent to recycling process; however, significant amounts of useless nonmetallic particles are also included. Recycling useful materials from used PCBs is a major challenging problem that must be solved in China renewable resource industries through harmless and feasible processes. In this article, a novel β-polypropylene (PP)/nonmetals composite was prepared and evaluated. The nonmetallic particles were treated with calcium pimelate (PA, a β-nucleating agent for PP) and then compounded with PP through melt blending method. The results show that when cooling and crystallizing from the melt, β-PP are formed because of the surface effects of PA. This observation is assumed as the source of good rigidity and toughness of prepared PP composites. In the composite containing 10 wt % nonmetallic particles treated with 5 wt % PA, the content of β-PP was found to be larger than 90% and the impact strength and flexural modulus of PP composite increased by 205.3 and 61.8%, respectively, compared with those of neat PP. Although the addition of PA-modified nonmetals slightly increased the tensile strength of PP, considering all factors, the optimal mass ratio of PP/nonmetals/PA composites to reach optimum mechanical properties was observed as 100/10/0.5. Thus, the application of treated nonmetals to prepare nonmetals/β-PP composites provides a promising way to recycle PCBs waste and produce useful PP composites.

通过熔融挤出法制备了玻璃纤维/餐厨钙化物/聚丙烯复合材料,并对复合材料进行了力学性能以及微观形貌的测试,结果表明经过庚二酸钙表面改性的刻蚀玻纤能够有效的提高材料的抗冲击性能,餐厨钙化物的加入进一步提升了冲击强度.其中,最高值为PP10GF1的61.3 J/m,相对PP的纯29.9 J/m提升了105.1％.因为改性后玻纤与PP相容性一般,拉伸强度整体上有少许的下降,添加餐厨钙化物后,由于会出现团聚现象,对拉伸强度产生了负面的影响.

In this paper, we present the results of research on the structure and properties of coral/PP biocomposites. Coral powder was chemically treated before use with pimelic acid (PA) through solution method. It was compounded with PP using melt extrusion, and the structures and properties of prepared PP composites were examined. The results show that the coral powder treated with PA performs as an efficient β-nucleating agent, resulting in the maximum K β value of 0.922 in the composites. It also significantly improved the impact strength by 220.6 % compared with that of the neat PP via improvement in the dispersion and compatibility in PP matrix. The melt crystallization behavior showed that addition of treated coral can promote heterogeneous nucleation.

There are many kinds of waste biomass calcium compounds,such as egg-shell and shell. In this pa-per,a method that using surface modified egg-shell powder as fillers of polypropylene( PP) to make PP composites through melt extrusion was presented. According to the analysis,egg-shell powder modified by pimelic acid could induce the formation of β-crystal to PP effectively,and the highest content of β-crystal reached 99%,making the impact strength of PP composites increase by 228%. Overall consideration,PP composites would achieve their best mechanical properties when the mass ratio of PP/egg-shell powder/pimelic acid was 100∶5∶0. 025.

通过庚二酸表面处理白贝粉，得到了有效的β成核剂，与聚乳酸一起加入到聚丙烯中，得到了冲击强度良好的复合材料。修饰后的白贝粉与PP相容性好，而聚乳酸则相容性一般，使得断裂伸长率有所下降。

ABSTRACTBlends of poly(phenylene sulfide) (PPS) and recycled poly(ether ether ketone) (r‐PEEK) were prepared using a twin‐screw extruder. The carbon nanotube (CNT) added to the blends not only improved the compatibility of the two polymers, but also affected the morphology of the immiscible PPS/r‐PEEK blends. R‐PEEK always forms the dispersed phase and PPS the continuous phase in such blends. In the composite, CNT particles were observed in the PPS phase, mostly distributes in the interface between PPS and PEEK. The results show that r‐PEEK improves the impact and tensile strength of PPS, but does not provide nucleation effect on PPS. However, CNT improved the flexural modulus of PPS/r‐PEEK blends and promoted the crystallization of r‐PEEK rather than that of PPS. The prepared PPS/r‐PEEK blends provided larger electrical conductivity than neat polymers. Adding 20 wt % CNT to blend resulted in composite with the minimum volume resistivity, a reduction of four orders of magnitude, compared with that of the neat blend. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42497.

本文针对侨校中高分子加工实验不适应内外招生混合教学,理论联系实际不足等问题,提出了案例法教学改革.经过内外招生混合教学、6大典型产品的案例教学以及教研结合三个主要方面的改革,加强了内外招生以及师生间的交流,充分发挥了内外招生各自的长处,培养了创新意识.

In this research, we used a twin-screw extruder to melt and blend PP-g-MA compatibilizer with β-polypropylene (PP)/polyamide 6 (PA6). The influences of the PA6 and PP-g-MA contents in PP/PA6 blends on crystallization and melting behavior of PP phase and morphology were investigated. The results showed that, when PP-g-MA copolymer was added to the β form of nucleated PP/PA6 blends, the anhydride groups in PP-g-MA and PA6 terminal amine groups react to form PP-g-PA graft copolymer in a two-phase interface. This reduces the interfacial tension, improves the interfacial adhesion, and reduces the size of PA6 domains in the blend. The generated PP-g-PA graft copolymer wrapped PA6 phase and buried the anhydride groups of PP-g-MA. When the proportion of PP-g-MA and PA6 was between 0.5 and 0.75, there was no longer interfering to the formation of β-crystals in the PP phase. The content of β-crystal of PP phase in blends was found to reach as large as 85.9%.

A serial of β-nucleated polypropylene (β-PP)/nano-calcium carbonate (nano-CaCO3)/ short poly(ethylene-terephthalate) (PET) fiber composites were prepared using extrusion blending. Maleic anhydride grafted PP (PP-g-MA) was used to modify the compatibility. The relationships among components, structure, and properties of the PP composites were studied. The results show that adding nano-CaCO3 improved the mechanical properties of the materials. Adding PET fiber increased the rigidity and toughness but the tensile strength decreased. PP-g-MA modified the compatibility of the components of the composites. Both PET fiber and nano-CaCO3 had nucleation effect on the PP crystallization and slightly induced the formation of β crystals. Ternary β-PP/nano-CaCO3/PET fiber composites contained high β-crystal content, and the compatibilizer exhibited synergy effect with β nucleating agent to further increase the β-crystal content in the blends. Mo’s method could satisfactorily describe the nonisothermal crystallization behavior of ternary composites, whereas Jeziorny and Ozawa methods failed to do the same ideally.

The hard particles of waste Dacron and nylon fabric fibers were prepared by the methods of dipping and polymerizing reactive monomers,and they were used to fill with polypropylene(PP).The results showed that reactive monomers infiltrated inside and outside in the fabric and formed the polymer layer to achieve hardening fabric purpose.In the PP composites,fabric fiber dispersed uniformly in PP resin in form of single fibers.Adding fiber could promote the crystallization of PP.The compatibility of Nylon fabric fiber and PP resin was superior to that between the Dacron fabric fiber and PP,thus PP composites filled with Nylon fabric fiber had better tensile property and toughness than the composites filled with Dacron fabric fiber,while the flexural modulus was inferior.Moreover,PP materials with 10 wt%fabric fiber content had the best comprehensive properties.