Abstract

In this study our previously prepared and fully characterized starch nanoparticles (SNPs) were graft copolymerize with acrylonitrile (AN) by microwave irradiation method without toxic chemical initiator. This was done to see the impact of microwave irradiation method as green and efficient tool with respect to reduction in organic solvents, toxic chemical initiator and exposer time on maximizing the graft yield % in comparison with other classical tools. The grafting parameters were expressed in terms of graft yield %. The latter was estimated gravimetrically (based on dry weight method) and titrimetrically (based on nitrogen %) to evaluate the best accurate standard metrological method for estimating the graft yield. The foremost factors affecting the grafting reaction were studied in terms of microwave power, acrylonitrile and starch nanoparticles concentration as well as contact time. The optimum reaction conditions were obtained when; starch nanoparticles, 1 g; acrylonitrile, 1.5 ml; microwave irradiation power, 500 W, reaction time 90 S were used. Starch nanoparticles and poly (AN)-starch nanoparticles graft copolymers were characterized by various analytical techniques. It was found from the obtained results that, Fourier transform infrared spectroscopy (FT-IR) analysis ascertains nitrile group attachment to starch nanoparticles chains. X-ray diffraction and scanning electron microscopy demonstrate an increased amorphous region of starch nanoparticles and grafted copolymers, while the thermo gravimetric analysis (TGA) emphasized the increase in thermal stability of the copolymers in comparison with starch nanoparticles counterparts. Tentative mechanisms, which demonstrate all occasions that happen during the whole course of the polymerization reaction, have been proffered.

中文翻译：

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使用微波辐射将丙烯腈接枝到淀粉纳米颗粒上的绿色高效工具

摘要

在这项研究中，我们通过微波辐照方法在无毒化学引发剂的情况下，将我们先前制备的且特性充分的淀粉纳米颗粒（SNP）与丙烯腈（AN）进行了接枝共聚。这样做是为了看到与其他传统工具相比，微波辐射方法作为绿色高效工具在减少有机溶剂，有毒化学引发剂和暴露时间方面对最大程度提高接枝率的影响。接枝参数以接枝产率％表示。后者通过重量分析（基于干重法）和滴定分析（基于氮％）进行评估，以评估用于估计嫁接产量的最佳准确标准计量学方法。根据微波功率研究了影响接枝反应的最主要因素，丙烯腈和淀粉纳米粒子的浓度以及接触时间。在以下条件下获得最佳反应条件：淀粉纳米颗粒，1 g；丙烯腈1.5毫升; 使用的微波辐射功率为500 W，反应时间为90S。通过各种分析技术对淀粉纳米颗粒和聚（AN）-淀粉纳米颗粒接枝共聚物进行了表征。从获得的结果中发现，傅立叶变换红外光谱法（FT-IR）分析确定了腈基对淀粉纳米颗粒链的附着。X射线衍射和扫描电子显微镜显示出淀粉纳米颗粒和接枝共聚物的无定形区域增加，而热重分析（TGA）则强调了与淀粉纳米颗粒对应物相比，共聚物的热稳定性有所提高。