Poly(caprolactone triol) as plasticizer agent for cellulose acetate films: influence of the preparation procedure and plasticizer content on the physico‐chemical properties

Abstract

The influence of the plasticizer content and film preparation procedure on the morphology, density, thermal and mechanical properties of cellulose acetate (CA) films plasticized with poly-(caprolactone triol) (PCL-T), were studied. Differential scanning calorimetry (DSC), thermal mechanical analysis (TMA), scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXD) and infrared spectroscopy (FT-IR) techniques were used. The films were prepared by dry-casting CA and CA/PCL-T in acetone or acetone/water solutions, which produced transparent and opaque films, respectively. In contrast to the transparent films, which were dense, the opaque films presented a porous morphology. However, the presence of PCL-T reduced the opaque film porosity, increasing, in consequence, its bulk density. The TMA results revealed that PCL-T reduced the glass transition temperature more significantly in the transparent than in opaque films. Only the transparent CA/PCL-T films presented a melting temperature, that reduced with higher concentrations of PCL-T, suggesting a higher ordering (crystallinity) when the films were prepared in the absence of water, as observed from WAXD curves. The mechanical properties also showed that the transparent films were more soft and tough than the opaque films. In summary, PCL-T was a good plasticizer agent for CA films due to the presence of hydrogen bonds between the components (FT-IR spectra). The presence of water in the dry casting process has a significant effect mainly on film morphology and mechanical properties.

Influência da adição de plastificante do processo de reticulação na morfologia, absorção de aguá e propriedades mecânicas de filmes de alginato de sódio

“…Aparentemente, a presença de 30% de sorbitol reduziu as interações polímero-polímero, aumentando o volume livre entre as cadeias, promovendo a diminuição no módulo de elasticidade. Comportamento similar foi observado por Meier et al 52 no estudo do efeito da poli (caprolactona triol) nas propriedades mecânicas de filmes de acetato de celulose. Para os filmes de alginato reticulados, o módulo de elasticidade diminui de 524 para 420 MPa com a quantidade de sorbitol variando de 0 para 10%, respectivamente, permanecendo praticamente constante na faixa de 10 a 30% de sorbitol, sugerindo a formação de filmes mais resistentes.…”

Microencapsulação do pesticida cipermetrina em blendas de P(3HB/PCL): caracterização e ensaio de liberação in vitro

“…Apresenta-se como um polímero semicristalino com grau de cristalinidade (α c ), na ordem de 50% e temperatura de transição vítrea (T g ) em torno de -70 °C. Em geral, a PCL apresenta a capacidade de formar blendas com vários polímeros em um vasto campo de composições, e tem sido usada como plastificante polimérico [18][19][20] . Num estudo de biodegradação de filmes homopoliméricos de P(3HB), P(3HB-V) e PCL em solo, Rosa et al [21] verificaram que P(3HB) degradou mais rapidamente que PCL e P(3HB-V) não apresentou degradação no período avaliado de 90 dias.…”

Poly(ethylene-co-methyl acrylate)/poly(caprolactone) triol blends for drug delivery systems: characterization and drug release

“…PCL-T is a biodegradable aliphatic polyester with low molecular weight, moderate water solubility and melting temperature close 33 o C. 19 There are three hydroxyl groups to which the ability to plasticize some natural polymers, such as soy protein and cellulose acetate, is attributed. 20,21 Meier et al 7 showed that the addition of liquid PCL-T (Mw 300 g/mol) to cellulose acetate films modulates drug permeability through a decrease in the polymer-polymer interactions (plasticizing effect) and the formation of small pores and channels through PCL-T dissolution .…”

“…21 EMA is an elastomeric copolymer composed of ethylene and methyl acrylate units, which are crystalline and amorphous, respectively. 22 EMA, just like EVA, has good mechanical properties for the development of controlled-drug release systems.…”

“…22 EMA, just like EVA, has good mechanical properties for the development of controlled-drug release systems. 23 Kanis et al 21 showed that poly(caprolactone triol) added to the EMA matrix produces immiscible films without significantly changing the elasticity modulus; moreover, the PCL-T melting point in the blend remained close to 30 o C.…”