Ring-opening polymerization of l-lactide and ε-caprolactone catalyzed by versatile tri-zinc complex: Synthesis of biodegradable polyester with gradient sequence structure

Lin, Limiao; Xu, Yun; Wang, Shuanjin; Xiao, Min; Ye, Meng

doi:10.1016/j.eurpolymj.2015.09.029

Cited by 23 publications

(18 citation statements)

References 42 publications

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“…. The equations for calculating l L and l C are

l_{normalL} = \frac{1}{2} [\frac{I_{normalLLL} + (I_{normalLLC} + I_{normalCLL}) / 2}{(I_{normalLLC} + I_{normalCLL}) / 2 + I_{normalCLC}} + 1]

l_{normalC} = \frac{I_{normalCCC} + I_{normalLCC}}{I_{normalCCL} + I_{normalLCL}} + 1

where I is the integral of the various central carbonyl carbon signals attributed to the triad sequences and the subscripts L and C refer to the lactidyl, –O–CH(CH 3 )–CO–, and caproyl, –O–(CH 2 ) 5 –CO–, repeat units.…”

Section: Resultsmentioning

confidence: 99%

“…The average sequence length ( l L and l C ) results in Table can be partly explained by the higher monomer reactivity of LL compared to CL . Lin et al . considered the LL and CL monomer reactivities in terms of the negative charge densities on the carbonyl oxygens.…”

Section: Resultsmentioning

confidence: 99%

“…To broaden their range of applications, copolymerization of l‐ lactide (LL) and ϵ‐caprolactone (CL) to produce poly( l‐ lactide‐ co ‐ϵ‐caprolactone), P(LL‐ co ‐CL), is an effective way of producing materials with the desired properties by tailoring their microstructures . Lin et al . demonstrated the effects of copolymer composition and chain microstructure on the crystallization behaviour as well as the thermal and mechanical properties of P(LL‐ co ‐CL) of various compositions.…”

Section: Introductionmentioning

confidence: 99%

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Physical and thermal properties of l‐lactide/ϵ‐caprolactone copolymers: the role of microstructural design

Phetsuk

Molloy

Nalampang

et al. 2019

Polymer International

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Understanding the underlying role of microstructural design in polymers allows for the manipulation and control of properties for a wide range of specific applications. As such, this work focuses on the study of microstructure–property relationships in l‐lactide/ϵ‐caprolactone (LL/CL) copolymers. One‐step and two‐step bulk ring‐opening polymerization (ROP) procedures were employed to synthesize LL/CL copolymers of various compositions and chain microstructures. In the one‐step procedure, LL and CL were simultaneously copolymerized to yield P(LL‐stat‐CL) statistical copolymers. In the two‐step procedure, poly(l‐lactide) (PLL) and poly(ϵ‐caprolactone) (PCL) prepolymers were synthesized in the first step before CL and LL respectively were added in the second step to yield P[LL‐b‐(CL‐stat‐LL)‐b‐LL] and P[CL‐b‐(LL‐stat‐CL)‐b‐CL] block copolymers as the final products. The findings reveal that, in addition to the copolymerization procedure employed, the length and type of the prepolymer play important roles in determining the chain microstructure and thereby the overall properties of the final copolymer. Moreover, control over the degree of crystallinity and the type of crystalline domains, which is controlled during the polymer chemistry process, heavily influences the physical and mechanical properties of the final polymer. In summary, this work describes an interesting approach to the microstructural design of biodegradable copolymers of LL and CL for potential use in biomedical applications. © 2019 Society of Chemical Industry

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“…. The equations for calculating l L and l C are

l_{normalL} = \frac{1}{2} [\frac{I_{normalLLL} + (I_{normalLLC} + I_{normalCLL}) / 2}{(I_{normalLLC} + I_{normalCLL}) / 2 + I_{normalCLC}} + 1]

l_{normalC} = \frac{I_{normalCCC} + I_{normalLCC}}{I_{normalCCL} + I_{normalLCL}} + 1

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Physical and thermal properties of l‐lactide/ϵ‐caprolactone copolymers: the role of microstructural design

Phetsuk

Molloy

Nalampang

et al. 2019

Polymer International

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“…이러한 생 분해성 고분자들 중에 외부환경에서 생물학적인 공격을 쉽게 받을 수 있는 지방족 폴리에스터가 주목을 받고 있다. [1][2][3][4] 대체 생분해성 고분자의 연구분야에서 재생 가능한 원료로 부터 생산된 생분해성 지방족 폴리에스터인 폴리락틱애시드 (poly(lactic acid), PLA)에 대한 연구가 활발하게 진행되고 있 다. 5,6 락타이드(lactide)와 락틱애시드(lactic acid) 단량체들은 옥수수나 사탕수수같은 곡물을 발효시켜 얻을 수 있다.…”

Section: 서 론unclassified

Ultrasound-Assisted Blends of Poly(lactic acid) and Poly(1,4-Cyclohexylene Dimethylene 1,4-Cyclohexane Dicarboxylate)

Lee¹

2016

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The effect of ultrasound irradiation on the blend of poly(lactic acid)(PLA) and poly(1,4-cyclohexylen dimethylene 1,4-cyclohexane dicarboxylate)(PCCD) was investigated. The blends of PLA/PCCD(50/50) (PCCD50) were prepared by a melt mixer attached with an ultrasonic device and their properties were analyzed. The properties of sonicated blends were found to be significantly dependent on the duration of the ultrasound irradiation. Surprisingly, for PCCD50, 1 min sonicated samples showed the impact strength over three times higher than untreated ones. The improvement was thought to be due to better adhesion between PLA and PCCD phases.

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“…The first approach ( Scheme 2 B) is to adjust the reactivity ratios of LA and εCL to nearly equal with a formation of the random copolymer in the course of living ROP; this approach can be potentially implemented via the catalyst’s design. This approach had been realized, more or less successfully, when used with sterically hindered complexes of Al [ 44 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ], Zn [ 43 , 62 , 63 , 64 , 65 , 66 ], Ti [ 67 , 68 , 69 , 70 , 71 , 72 , 73 ], Zr [ 70 , 71 ], Hf [ 70 ], Mo [ 74 ], Mg or alkali-earth metals [ 45 , 75 ] and lanthanides [ 76 , 77 , 78 ]. The formation of random copolymers with the catalysis by metal chelates was usually attributed to higher inhibition of the coordination of LA relative to εCL due to higher steric hindrance for LA coordination [ 50 , 79 ].…”

Section: Introductionmentioning

confidence: 99%

Comparative Experimental and Theoretical Study of Mg, Al and Zn Aryloxy Complexes in Copolymerization of Cyclic Esters: The Role of the Metal Coordination in Formation of Random Copolymers

et al. 2020

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Homogeneity of copolymers is a general problem of catalytic coordination polymerization. In ring-opening polymerization of cyclic esters, the rational design of the catalyst is generally applied to solve this problem by the equalization of the reactivities of comonomers—however, it often leads to a reduction of catalytic activity. In the present paper, we studied the catalytic behavior of BnOH-activated complexes (ВНТ)Mg(THF)2nBu (1), (ВНТ)2AlMe (2) and [(ВНТ)ZnEt]2 (3), based on 2,6-di-tert-butyl-4-methylphenol (BHT-H) in homo- and copolymerization of L-lactide (lLA) and ε-caprolactone (εCL). Even at 1:5 lLA/εCL ratio Mg complex 1 catalyzed homopolymerization of lLA without involving εCL to the formation of the polymer backbone. On the contrary, Zn complex 3 efficiently catalyzed random lLA/εCL copolymerization; the presence of mono-lactate subunits in the copolymer chain clearly pointed to the transesterification mechanism of copolymer formation. Both epimerization and transesterification side processes were analyzed using the density functional theory (DFT) modeling that confirmed the qualitative difference in catalytic behavior of 1 and 3: Mg and Zn complexes demonstrated different types of preferable coordination on the PLA chain (k2 and k3, respectively) with the result that complex 3 catalyzed controlled εCL ROP/PLA transesterification, providing the formation of lLA/εCL copolymers that contain mono-lactate fragments separated by short oligo(εCL) chains. The best results in the synthesis of random lLA/εCL copolymers were obtained during experiments on transesterification of commercially available PLLA, the applicability of 3/BnOH catalyst in the synthesis of random copolymers of εCL with methyl glycolide, ethyl ethylene phosphonate and ethyl ethylene phosphate was also demonstrated.

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Ring-opening polymerization of l-lactide and ε-caprolactone catalyzed by versatile tri-zinc complex: Synthesis of biodegradable polyester with gradient sequence structure

Cited by 23 publications

References 42 publications

Physical and thermal properties of l‐lactide/ϵ‐caprolactone copolymers: the role of microstructural design

Physical and thermal properties of l‐lactide/ϵ‐caprolactone copolymers: the role of microstructural design

Ultrasound-Assisted Blends of Poly(lactic acid) and Poly(1,4-Cyclohexylene Dimethylene 1,4-Cyclohexane Dicarboxylate)

Comparative Experimental and Theoretical Study of Mg, Al and Zn Aryloxy Complexes in Copolymerization of Cyclic Esters: The Role of the Metal Coordination in Formation of Random Copolymers

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