大约十年前，出于对可持续性的考虑，杰夫·凯奇马克(杰夫Catchmark)开始试验可能用于替代塑料的生物材料. 他之所以对纤维素感兴趣，是因为它是最大的可持续性材料, renewable material on earth.
宾州大学公园. 十大网投平台信誉排行榜的研究人员开发了一种廉价的生物材料，可用于替代包装中的塑料屏障涂层和许多其他应用, 谁 predict its adoption would greatly reduce pollution.
Completely compostable, 这种材料是一种多糖多电解质复合物，由几乎等量的木材或棉花处理过的纤维素浆组成, 和壳聚糖, 哪一种是从几丁质(节肢动物和甲壳类动物外骨骼的主要成分)中提取出来的. 几丁质的主要来源是堆积如山的龙虾壳, crabs and shrimp consumed by humans.
这些环保屏障涂料有许多应用，从防水纸, to 涂料 for ceiling tiles and wallboard, to food 涂料 to seal in freshness, according to lead researcher Jeffrey Catchmark, professor of agricultural and biological engineering, College of Agricultural Sciences.
"The material's unexpected strong, 不溶性粘接剂的性质是有用的包装以及其他应用, such as better performing, fully natural wood-fiber composites for construction and even flooring,他说. “这项技术有可能被应用到食品中，以减少油炸过程中脂肪的摄入，保持食品的脆度。. 由于这种涂层基本上是以纤维为基础的，所以它是一种向饮食中添加纤维的方法."
羧甲基纤维素和壳聚糖之间惊人的坚固和持久的结合是关键, 他解释说. 这两种非常便宜的多糖已经用于食品工业和其他工业部门，它们具有不同的分子电荷，并锁在一起形成一个复合物，为不透水的薄膜提供基础, 涂料, 粘合剂等.
如果这些屏障涂料取代美国每年使用的数百万吨与食品包装相关的石油基塑料，那么减少污染的潜力是巨大的——在全球范围内更是如此, Catchmark指出.
他指出，全球塑料产量每年接近3亿吨. 近年来，美国有超过2900万吨的塑料成为城市固体废物.S. and almost half was plastic packaging. 预计全球生产的塑料中有10%将成为海洋垃圾, representing a significant ecological and human health threat.
The material is comprised of cellulose pulp from wood or cotton, 和壳聚糖, 源自几丁质, the primary ingredient in the exoskeletons of arthropods and crustaceans. The main source of 几丁质 is shells from lobsters, crabs and shrimp.
多糖-电解质复合涂层在研究中表现良好, the findings of which were published recently in Green Chemistry. Paperboard coated with the biomaterial, 由羧甲基纤维素和壳聚糖的纳米结构纤维颗粒组成, exhibited strong oil and water barrier properties. The coating also resisted toluene, 庚烷和盐溶液表现出改善的干湿机械和水蒸气阻隔性能.
“这些结果表明，在许多商业应用中，多糖聚电解质复合物基材料可能是合成聚合物的竞争性屏障替代品,Catchmark说。, 谁, in concert with Penn State, has applied for a patent on the 涂料.
“除了, this work demonstrates that new, 多多糖系统在静电络合作用下产生了意想不到的特性, enabling new high-performance applications."
大约十年前，出于对可持续性的考虑，Catchmark开始试验可能用于替代塑料的生物材料. He became interested in cellulose, the main component in wood, because it is the largest volume sustainable, renewable material on earth. Catchmark研究了它的纳米结构——它是如何在纳米尺度上组装的.
他相信他可以开发出更坚固的天然材料，并改善其性能, 这样它们就可以与不可持续且会产生污染的合成材料竞争，比如用于纸板的低密度聚乙烯层压板, Styrofoam and solid plastic used in cups and bottles.
“挑战在于, to do that you've got to be able to do it in a way that is manufacturable, and it has to be less expensive than plastic," Catchmark explained. “因为当你改变一些更环保或可持续的东西时, you really have to pay for the switch. 因此，为了让公司真正从中获利，它必须更便宜. 这就给可持续材料带来了一个问题——必须用更低的成本来克服这种惯性."
羧甲基纤维素和壳聚糖之间惊人的坚固和持久的结合是关键. The two very inexpensive polysaccharides, already used in the food industry and in other industrial sectors, 有不同的分子电荷并锁在一起形成一个复合体，为不透水的薄膜提供基础, 涂料, 粘合剂等.
由农业科学学院创新研究应用基金资助, Catchmark目前正致力于为各种产品在不同的行业部门开发商业化合作伙伴.
“我们现在正努力迈出最后一步，对世界产生真正的影响, 让工业人员停止使用塑料，转而使用这些天然材料,他说. "So they (consumers) have a choice — after the biomaterials are used, 它们可以回收利用, buried in the ground or composted, and they will decompose. Or they can continue to use plastics that will end up in the oceans, where they will persist for thousands of years."
Also involved in the research were Snehasish Basu, 博士后学者, 亚当·普林斯基, master's degree student, now instructor of engineering at 十大网投平台信誉排行榜阿尔图纳分校. 十大网投平台信誉排行榜材料研究所的工作人员为该项目提供了帮助.
美国.S. Department of Agriculture supported this work. Southern Champion Tray, 查塔努加的, 田纳西州, provided 纸板 and information on its production for experiments.
