Polymers and Environment II. Development of New Biodegradable Polymers.

Shirahama, Hiroyuki; Mizuma, Kiyoshi; Kawaguchi, Yoshihide; Shiomi, Masaki; Yasuda, Hajime

doi:10.1295/koron.50.821

Cited by 10 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Those enzymes were selected from the following reasons. Cholesterol esterase has a higher substrate specificity for aliphatic polyesters with relatively longer methylene chains, and hence, for more hydrophobic polyesters such as poly(ϵ‐caprolactone) [poly(CL)] than those with shorter methylene chains like poly(β‐propiolactone) [poly(PL)] 8. Whereas R. delemar lipase has the opposite specificity, i.e., the lipase degraded more poly(PL) than poly(CL) 9.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and enzymatic degradation of high molecular weight aliphatic polyesters

Shirahama

Kawaguchi

Aludin

et al. 2001

J. Appl. Polym. Sci.

Self Cite

View full text Add to dashboard Cite

The aliphatic polyesters with high molecular weight have been prepared according to two methods. First is the synthesis of the polyesters by polycondensation of dimethyl succinate (DMS) with 1,4‐butanediol (BD) using various metal alkoxides as a catalyst. Among the metal alkoxides used, titanium tetraisopropoxide [Ti(OiPr)4] gave the best results (highest molecular weight and yield). Thus, we have prepared aliphatic polyesters using a variety combinations of diesters [MeOOC—(CH2)x—COOMe, x = 2–8] with BD by the catalysis of Ti(OiPr)4. The polyesters with high number‐average molecular weight (Mn > 35,000), except dimethyl adipate (DMA, x = 4)/BD polyester (Mn = 26,900), were obtained in high yield. The melting temperatures (Tm) of polyesters were relatively low (43.4–66.8°C) except that (115.6°C) of the DMS/BD polyester. Second is the synthesis of high molecular weight polyesters by chain extension reaction of lower molecular weight (Mn = 15,900–26,000) polyesters using hexamethylene diisocyanate (HDI) as a chain extender. The Mn values of chain‐extended polyesters consequently increased more than two times (Mn = 34,700–56,000). The thermal properties of polyesters hardly changed before and after chain extension. Enzymatic degradations of the polyesters were performed using three different enzymes (cholesterol esterase, lipase B, and Rhizopus delemar lipase) before chain extension. The enzymatic degradability varied depending on both thermal properties of polyesters [melting temperature and heat of fusion (crystallinity)] and the substrate specificity of enzymes, but it was the following order: cholesterol esterase > lipase B > R. delemar lipase. The 1H‐NMR spectrum of water‐soluble degraded products of the polyester indicated that the polyester was degraded into a condensation product of diol with diester in a monomer form. The enzymatic degradation of chain extended polyesters was slightly smaller than that before chain extension, but proceeded steadily. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 340–347, 2001

show abstract

Section: Resultsmentioning

confidence: 99%

Synthesis and enzymatic degradation of high molecular weight aliphatic polyesters

Shirahama

Kawaguchi

Aludin

et al. 2001

J. Appl. Polym. Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Recently, Yasuda et al reported that when (R)-MOHEL reacted with e-caprolactone or ó-valerolactone, the corresponding copolymers were afforded. 6 Here we report on the synthesis of a new biodegradable polymer, poly…”

mentioning

confidence: 99%

Ring-Opening Copolymerization of (R)-.beta.-Butyrolactone with (R)-3-Methyl-4-oxa-6-hexanolide: A New Biodegradable Poly(ester-ether)

Hori¹,

Yamaguchi²

1995

Macromolecules

View full text Add to dashboard Cite

“…Similar results were observed for the copolymers of an optically active lactone ((R)-MOHEL) with CL. 16 The biodegradation of EC/CL copolymers in seawater is given in Figure 7. Degradability in seawater shows much the same tendency as that in activated sludge, indicating that similar bacteria exist in these two environments.…”

Section: Biodegradation Of Polymersmentioning

confidence: 99%

Synthesis and Biodegradability of Copolymers of Ethylene Carbonate with Lactones

Shirahama

Kanetani

Yasuda

2000

Polym J

Self Cite

View full text Add to dashboard Cite

The copolymers of ethylene carbonate (EC) with E-caprolactone (CL) or li-valerolactone (VL) were synthesized using (C 5 Me 5 ) 2 SmMe(THF) as initiator. We prepared EC/CL and ECNL copolymers with a high molecular weight (M,,~140000) without decarboxylation from the EC unit. The EC/CL copolymers were obtained in a higher carbonate content (up to ca. 30 mo!%) and in a better yield compared with ECNL copolymers. The 1 H NMR and thermal analyses revealed that these copolymers exhibit random arrangement. The enzymatic degradations of EC/lactone copolymers were investigated using lipoprotein lipase and cholesterol esterase (both from Pseudomonas sp.). The degradability of the copolymers was much improved compared with that of lactone homopolymers. Greater degradation was observed for the lipase-induced degradation than the cholesterol esterase. The biodegradability of these copolymers in natural environments (viz., in activated sludge and seawater) was examined. As compared with enzymatic degradations, similar good biodegradability was observed for EC/CL copolymers, while a poor degradation was seen for ECNL copolymers.

show abstract

Polymers and Environment II. Development of New Biodegradable Polymers.

Cited by 10 publications

References 0 publications

Synthesis and enzymatic degradation of high molecular weight aliphatic polyesters

Synthesis and enzymatic degradation of high molecular weight aliphatic polyesters

Ring-Opening Copolymerization of (R)-.beta.-Butyrolactone with (R)-3-Methyl-4-oxa-6-hexanolide: A New Biodegradable Poly(ester-ether)

Synthesis and Biodegradability of Copolymers of Ethylene Carbonate with Lactones

Contact Info

Product

Resources

About