Copolymers of c-caprolactone and L-lactide (c-CL/L-LA) and c-caprolactone and DL-lactide (c-CL/DL-LA) were synthesized with compositions 80/20,60/40, and 40/60 (wt % in feed). The polymerization temperature was 140°C and Sn(I1)octoate was used as a catalyst. The effect of the comonomer ratio on the
Biodegradable lactone copolymers. II. Hydrolytic study of ε-caprolactone and lactide copolymers
✍ Scribed by M. Malin; M. Hiljanen-Vainio; T. Karjalainen; J. Seppälä
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 784 KB
- Volume
- 59
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
Copolymers of c-CL/L-LA and c-CLIDL-LA were allowed to age in a buffer solution of pH 7 at 23 and 37°C. The effects of time and temperature on the rate of hydrolysis were examined by various techniques including weighing (water absorption and weight loss), SEC (molecular weight and polydispersity), and DSC (thermal properties). For comparison, the hydrolytic behavior of PLLA, PDLLA, and commercial PCL homopolymers was investigated by the same methods. SEC measurements showed that molecular weights of the copolymers and PLA homopolymers started to decrease during the first week of hydrolysis, but significant mass losses occurred only much later. As expected, there was no change in either molecular weight or mass of PCL during the hydrolysis study. The kinetic results for copolymers and homopolymers were calculated to study the degradation mechanism. During hydrolysis, the crystallinity of the initially semicrystalline copolymers increased and some crystallinity appeared in the initially amorphous L-LA-containing copolymers.
📜 SIMILAR VOLUMES
Copolymers of c-CL/L-LA and c-CLIDL-LA and for comparison homopolymers PLLA, PDLLA, and PCL were allowed to age in a buffer solution of pH 7 a t 23 and 37°C and studied for the changes in the mechanical properties taking place as a function of hydrolysis time. Tensile modulus measurements showed the
## Abstract For the triblock copolymer of ε‐caprolactone, trimethylene carbonate, and L‐lactide, where L‐lactide blocks form the two ends, there is a range of compositions over which elastomeric behavior is obtained. Within this composition range, these polymers show good creep and recovery at ambi
## Abstract Biodegradable and photocurable block copolymers of __ε__‐caprolactone and L‐lactide were synthesized by polycondensation of PLLA diol ($\overline {M} \_{{\rm n}} $ = 10 000 g · mol^−1^), PCL diol ($\overline {M} \_{{\rm n}} $ = 10 000 g · mol^−1^), and a chain extender bearing a coumari
The degradation of poly(oxyethylene) -poly( 1-caprolactone) (POE-PCL) multiblock copolymers was investigated at 37ЊC in a 0.13M, pH 7.4 phosphate buffer selected to mimic in vivo conditions. The copolymers were obtained by coupling polycaprolactone diols and poly(ethylene glycol) diacids using dicyc