外文翻譯----殼聚糖聚乙烯醇復(fù)合水凝膠的制備-文庫吧資料
2025-05-22 11:37本頁面
【正文】 Chi/PVA blends, with different polymer proportions and crosslinkedby GA. A typical swelling behavior is shown in performed for Chi/PVA blend [25:75] before and after chemical crosslinking with 1% and 5% of content. Brie?y, the observed pattern indicated an initial rapid mass uptake,usually in approximately 30 min, followed by mass stabilization over a 192 h period. Visual inspection of the samples also shows appreciable volume increase. The results have revealed a strong in?uence of the crosslinkingon the swelling volume, from about 700% in Chi/PVA sample before crosslinking, it dropped to 400% and 200%,with % and 5% GA, 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.。 2℃ (solution A), as previously reported by our group [7–9]. PVA 5% solution was let to cool down to room temperature and the pH was corrected to ( 177?？傊@些研究擴(kuò)大了殼聚糖 /聚乙烯醇混合物等一些生物材料在醫(yī)學(xué)領(lǐng)域的應(yīng)用的潛力，如生物材料，毒品運(yùn)載工具和皮膚組織工程。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)。結(jié)果表明，通過改變殼聚糖與聚乙烯醇中的比例，不同的交聯(lián)劑濃度，水凝膠的整體性能是可以改變的。盡管目前的研究不同于其他殼聚糖的研究報道，但聚乙烯醇和殼聚糖的溶脹行為與這些結(jié)論相似，聚乙烯醇的溶脹度在 500%以上，殼聚糖大約是 200%，取決于溶液中的 PH 值，溫度等等。
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