外文翻譯----殼聚糖聚乙烯醇復合水凝膠的制備(完整版)
【正文】 , respectively. That fact is attributed to a more rigid work formed by the interintra polymer chain reactions that have occurred, reducing the ?exibility and number of hydrophilic groups of hydrogel which is unfavorable to the swelling rate. So, these results are corresponding to the hydrogel mechanism. Before GA reaction, the PVA chains are physically entangled with the chitosan chains, forming a hydrogel work. In the sequence, when the GA content was increased the chemical crosslinking has occurred, forming covalent bonds among chains, ?xing and reducing polymer mobility, which resulted in the lower swelling rate, in case, less than half of that blend without chemical crosslinking.。這現(xiàn)象產(chǎn)生的原因是形成了一個十分緊密的網(wǎng)絡(luò)結(jié)構(gòu)。 改變殼聚糖在聚乙烯醇中的配比，分析影響如圖 5 所示。典型的溶脹行為如圖 4 所示：殼聚糖 /聚乙 烯醇配比（ 25： 75），交聯(lián)劑用量為 1%和 5%。殼聚糖 聚乙烯醇復合水凝膠樣品的化學交聯(lián)反應(yīng)產(chǎn)生凹痕已確定為（ X： Y： Z）三種因素， X 為殼聚糖的含量， Y 為聚乙烯醇的含量， Z 為戊二醛（質(zhì)量分數(shù) %）。 ）。 5％的聚乙烯醇完全溶解后，讓其冷卻到室溫和用 M 鹽酸（ ?? ）把 pH 值控制在（ 177。隨著進一步反應(yīng)，溶液不斷塑化，接著在室溫下其讓干燥 72 至 120 h，最后在 40℃干燥 24 小時（恒重） 。 溶脹度測試 溶脹度的實驗主要研究殼聚糖 /聚乙烯醇水凝膠合成時，不同混合比例和戊二醛交聯(lián)劑用量對溶脹度的影響。接著，當戊二醛加入，發(fā)生化學交聯(lián)反應(yīng)，在鏈段間形成共價鍵，固定聚合物和降低流動性，引起較少的溶脹率，也許，只有一半不到的混合物發(fā)生交聯(lián)反應(yīng)。這次的實驗報告已 指出溶脹性能與殼聚糖含量的增加，還有交聯(lián)試劑用量的增大有很大的關(guān)系。 The effect of chitosan to PVA ratio was also analyzed and the results are presented in Fig. 5. It was veri?ed that the swelling behavior is especially in?uenced by the chitosan content in the blend, crosslinked at %GA,where the swollen mass reduced by increasing the chitosan concentration and reaching a minimum value at [Chi/PVA] =50:50. The swelling degree reduced from 200%(pure PVA) to 100% (50:50 Chi/PVA), then raised to about140% at Chi/PVA ratios of 75:25 and 100% chitosan. These results are supported
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