Srivastava Kavita, Rathore Ashwani Kumar, Srivastava Deepak
Department of Chemistry, V.S.S.D. College, Nawab Ganj, Kanpur 208 002, U.P., India.
School of Chemical Technology - Department of Chemical Engineering, H. B. Technical University (Formerly H. B. Technological Institute), Kanpur 208 002, U.P., India.
Spectrochim Acta A Mol Biomol Spectrosc. 2018 Jan 5;188:99-105. doi: 10.1016/j.saa.2017.06.066. Epub 2017 Jul 3.
Cashew nut shell liquid (CNSL), an agricultural renewable resource material, produces natural phenolic distillates such as cardanol. Cardanol condenses with formaldehyde at the ortho- and para-position of the phenolic ring under acidic or alkaline condition to yield a series of polymers of novolac- or resol-type phenolic resins. These phenolic resins may further be modified by epoxidation with epichlorohydrin to duplicate the performance of such phenolic-type novolacs (CFN). The structural changes during curing of blend samples of epoxy and carboxyl terminated poly (butadiene-co-acrylonitrile) (CTBN) were studies by Fourier-transform infrared (FTIR) spectrophotometer. The epoxy samples were synthesized by biomass material, cardanol. Blend sample was prepared by physical mixing of CTBN ranging between 0 and 20weightpercent CTBN liquid rubber into cardanol-based epoxidized novolac (CEN) resin. The FTIR spectrum of uncured blend sample clearly indicated that there appeared a band in the region of 3200-3500cm which might be due to the presence of phenolic hydroxyl group and OH group of the opened epoxide. Pure epoxy resin showed peaks near 856cm which might be due to oxirane functionality of the epoxidized novolac resin. Both epoxy and its blend sample was cured with polyamine. The cure temperature of CEN resin was found to be decreased by the incorporation of CTBN. The decomposition behavior was also studied by thermogravimetric analyzer (TGA). Two-step decomposition behavior was observed in both epoxy and its blend samples.
腰果壳液（CNSL）是一种农业可再生资源材料，可生产天然酚类馏出物，如腰果酚。在酸性或碱性条件下，腰果酚在酚环的邻位和对位与甲醛缩合，生成一系列线型酚醛清漆型或甲阶酚醛型酚醛树脂聚合物。这些酚醛树脂可通过用环氧氯丙烷进行环氧化进一步改性，以复制此类酚醛型线型酚醛清漆（CFN）的性能。通过傅里叶变换红外（FTIR）分光光度计研究了环氧和羧基封端的聚（丁二烯-共-丙烯腈）（CTBN）共混样品固化过程中的结构变化。环氧样品由生物质材料腰果酚合成。共混样品是通过将0至20重量百分比的CTBN液态橡胶物理混合到腰果酚基环氧化线型酚醛清漆（CEN）树脂中制备的。未固化共混样品的FTIR光谱清楚地表明，在3200 - 3500cm区域出现了一个谱带，这可能是由于酚羟基和开环环氧的OH基团的存在。纯环氧树脂在856cm附近出现峰，这可能是由于环氧化线型酚醛清漆树脂的环氧乙烷官能团。环氧及其共混样品均用多胺固化。发现加入CTBN会降低CEN树脂的固化温度。还通过热重分析仪（TGA）研究了分解行为。在环氧及其共混样品中均观察到两步分解行为。
