国产三级在线看完整版-内射白嫩大屁股在线播放91-欧美精品国产精品综合-国产精品视频网站一区-一二三四在线观看视频韩国-国产不卡国产不卡国产精品不卡-日本岛国一区二区三区四区-成年人免费在线看片网站-熟女少妇一区二区三区四区

儀器網(wǎng)(yiqi.com)歡迎您!

| 注冊2 登錄
網(wǎng)站首頁-資訊-話題-產(chǎn)品-評測-品牌庫-供應(yīng)商-展會-招標(biāo)-采購-知識-技術(shù)-社區(qū)-資料-方案-產(chǎn)品庫-視頻

應(yīng)用方案

儀器網(wǎng)/ 應(yīng)用方案/ MwA測量應(yīng)用案例-6

立即掃碼咨詢

聯(lián)系方式:400-822-6768

聯(lián)系我們時(shí)請說明在儀器網(wǎng)(www.sdczts.cn)上看到的!

掃    碼    分   享
文獻(xiàn)名: Online Monitoring of Copolymerization Involving Comonomers of Similar Spectral Characteristics 作者: Alina M. Alb , Pascal Enohnyaket , Michael F. Drenski , Aaron Head , Alex W. Reed , and Wayne F. Reed Physics Department, Tulane University, New Orleans, Louisiana 70118 摘要:Automatic continuous online monitoring of polymerization reactions (ACOMP) was applied to free radical copolymerization of acrylic comonomers, whose spectral characteristics are very similar. Determination of the instantaneous concentration of each comonomer during the reaction was made possible by incorporating a full spectrum UV spectrophotometer into the detector train. The working assumption was that a UV spectrum at any instant during conversion is a linear combination of the normalized basis spectra of the comonomers and the copolymer, and that the unknown comonomer concentrations can be found by minimizing the error between measured and computed spectra over many wavelengths, even when spectral differences are small at any given wavelength. Here, the copolymerization of butyl acrylate (BA) and methyl methacrylate (MMA) was monitored under different starting composition ratios. Continuous conversion kinetics, composition drift, and average composition distribution are all found from the data, in addition to the evolution of weight-average intrinsic viscosity and molar mass Mw. Reactivity ratios, rmma = 0.40 ± 0.05 and rba = 2.58 ±0.1, are close to the averages found from a literature survey over a wide range of conditions. Comonomer conversion results were independently cross-checked by GPC. Increasing the content of BA in the copolymer was found to increase Mw, while also leading to a significant increase in chain stiffness. This work sets the stage for extension to copolymerization of three and more comonomers.

參與評論

全部評論(0條)

推薦方案

在線留言

上傳文檔或圖片,大小不超過10M
換一張?
取消