当前位置: X-MOL 学术Biomacromolecules › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Controlled Radical Copolymerization of Cinnamic Derivatives as Renewable Vinyl Monomers with Both Acrylic and Styrenic Substituents: Reactivity, Regioselectivity, Properties, and Functions.
Biomacromolecules ( IF 6.2 ) Pub Date : 2018-10-25 , DOI: 10.1021/acs.biomac.8b01298
Yuya Terao 1 , Kotaro Satoh 1 , Masami Kamigaito 1
Affiliation  

A series of cinnamic monomers, which can be derived from naturally occurring phenylpropanoids, were radically copolymerized with vinyl monomers such as methyl acrylate (MA) and styrene (St). Although the monomer reactivity ratios were close to zero for all the cinnamic monomers, such as methyl cinnamate (CAMe), cinnamic acid (CA), N-isopropyl cinnamide (CNIPAm), cinnamaldehyde (CAld), and cinnamonitrile (CN), they were incorporated into the copolymers and significantly increased the glass transition temperatures despite the relatively low incorporation rates of up to 40 mol % due to their rigid 1,2-disubstituted structures. The regioselectivity of the radical copolymerization of CAMe was evaluated on the basis of the results of ruthenium-catalyzed atom transfer radical additions as model reactions. The obtained products suggest that the radicals of MA and St predominantly attack the vinyl carbon of the carbonyl side of CAMe and that the propagation of CAMe mainly occurs via the styrenic radical. The ruthenium-catalyzed living radical polymerization, nitroxide-mediated polymerization (NMP), and reversible addition-fragmentation chain transfer (RAFT) polymerization provided the copolymers with controlled molecular weights, narrow molecular weight distributions, and controlled comonomer compositions. The copolymers of N-isopropylacrylamide (NIPAM) and CNIPAm prepared via RAFT copolymerization showed thermoresponsivity with a lower critical solution temperature (LCST) that could be tuned by altering the comonomer incorporation and a higher LCST than the copolymers of NIPAM and St, which possessed similar molecular weights and similar NIPAM contents, due to the additional N-isopropylamide groups in the CNIPAm units compared to the St units.

中文翻译:

肉桂衍生物作为具有丙烯酸和苯乙烯取代基的可再生乙烯基单体的受控自由基共聚:反应性,区域选择性,性质和功能。

将一系列可衍生自天然存在的苯基丙烷的肉桂酸酯单体与乙烯基单体(如丙烯酸甲酯(MA)和苯乙烯(St))自由基共聚。尽管所有肉桂酸酯单体(如肉桂酸甲酯(CAMe),肉桂酸(CA),N-异丙基肉桂酰胺(CNIPAm),肉桂醛(CAld)和肉桂腈(CN)的单体反应率均接近零。尽管由于它们的刚性的1,2-二取代的结构相对低的高达40mol%的掺入率,但仍将其引入共聚物中并显着提高了玻璃化转变温度。基于钌催化的原子转移自由基作为模型反应的结果,评估了CAMe自由基共聚的区域选择性。所得产物表明MA和St的自由基主要攻击CAMe的羰基侧的乙烯基碳,并且CAMe的传播主要通过苯乙烯自由基发生。钌催化的活性自由基聚合,氮氧化物介导的聚合(NMP)和可逆的加成-断裂链转移(RAFT)聚合为共聚物提供了可控的分子量,窄的分子量分布和可控的共聚单体组成。通过RAFT共聚制备的N-异丙基丙烯酰胺(NIPAM)和CNIPAm的共聚物显示出比较低的临界溶液温度(LCST)更高的热响应性,该临界溶液温度可以通过改变共聚单体的掺入量和比LC / NIPAM和St的共聚物更高的LCST来调节,
更新日期:2018-10-25
down
wechat
bug