水性聚氨酯添加界面活性剂之研究-东海大学化学工程与材料工程学系.doc

PAGE PAGE 6 水性聚氨酯添加界面活性劑之研究 李蕙惜、喬緒明* 東海大學化工所 Abstract Two component water borne Polyurethane (PU) crosslinked with Polyisocyanate has been recognized to have superior water-resistance and solvent-resistance, thermal stabilities, ...etc.. However, the drying rate of water borne PU to remove moisture is too slow in room temperature. To enhance the water removing rate, higher drying temperarute is suggested. Though the unwanted side reaction of polyisocyanate hydration follows. We chose to use a dual surfactant system which combines an anionic (SDS) and a nonionic surfactant (NP50) in this work. With the surfactant on the surface of polymer emulsion, hydration of NCO groups was slowed down until the emulsion broke under contunaouly drying. Higher corsslinking density with PU, and therefore better performance in thermal and mechanical behavior resulted. Results show that the raising the drying temperature further ensured higher crosslinking density. Comparing to the room-temperature drying process proposed by Bayer, our system offered almost 200% increases in both the tensile strength and the Peel strength. As to the adhesive and tensile test, PU and crosslinker emulsified with surfactant simultaneously have the better results. 一、中文摘要 水性PU樹脂添加多異氰酸酯類的交聯劑以提高其耐水、耐溶劑、熱學、機械及黏著性質。水性PU使用時，在室溫下除水的乾燥速度緩慢，為了加快除水速率，因此提高溫度做乾燥，然而乾燥溫度的提高，卻又引發了多異氰酸酯類交聯劑的水解反應問題。本研究中採用SDS/NP50複合型的界面活性劑，加入於雙成分的水性PU中，將多異氰酸酯包覆起來，因此在提高溫度乾燥時能減少NCO水解問題，而與PU產生交聯反應，形成高分子的網狀結構。實驗結果得知，提高乾燥溫度及加入界面活性劑的做法下，相較於bayer在室溫下乾燥的處理程序，我們所得到的拉伸強度及剝離強度都有約200%以上的提昇。並且交聯劑、界面活性劑和水性PU一起乳化的方法（即方法F）對其拉伸、黏著性質及熱穩定性，都將有較優良的表現。 Keywords: Water borne, PU, surfactant. 二、簡介 近10多年來，一些國家制定了環保和溶劑法規，因此促使水性PU黏著劑的發展(1-5)。然而水性PU膠膜的耐水性和耐溶劑性差，且水解也將會降低PU的熱穩定性，減低他的使用壽命，及影響到他的機械性質，所以改善水性聚氨酯的水解問題為目前重要的研究方向(6,7)。Chen等人提到水性PU可與環氧樹脂、聚丙烯酸、Glycidyl methacrylate(GMA)共聚物共混，形成IPN(8)、一些文獻中（9,10,6）也提到可將三聚氰胺(Melamine)、氮丙碇(Aziridine)、環氧樹脂(Epoxy)、碳化二亞胺(Carbodiimide)及水分散型多異氰酸酯等，加入水性PU中，與PU產生交聯反應，提高其交聯度。目前所使用的水分散型多異氰酸酯當作交聯劑已有相 當多的應用，效果也較佳（1）。 然而多異氰酸酯加入水性PU時，將難以分散