The influence of 4,4’-bis(6-hydroxyhexoxy)biphenyl moieties on properties of polyurethanes based on 4,4’-methylenebis(cyclohexyl isocyanate)

Łazarewicz, T.; Haponiuk, Józef T.; Balas, Adolf

doi:10.1515/epoly.2006.6.1.653

Cited by 4 publications

(4 citation statements)

References 18 publications

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“…(1), [41] considering a melting enthalpy of 142 J/g for 100% crystalline PHB as cited in the literature. [42,43] where X c is the crystallinity (%), ΔH m is the melting enthalpy of the polymer (J/g), W p is the proportion of the polymer in the blend, and ΔH m100% is the melting enthalpy of the 100% crystalline polymer.…”

Section: Resultsmentioning

confidence: 99%

Characterization and biodegradation behavior of bio-based poly(lactic acid) and soy protein blends for sustainable horticultural applications

et al. 2015

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Adipic anhydride-plasticized soy protein (SP.A) was blended with poly(lactic acid) (PLA) at two concentrations (50/50 and 33/67) and was evaluated for use as a sustainable replacement for petroleum plastic in horticulture crop containers. Following the discovery that SP.A/PLA blends provide additional functions above that of petroleum plastic for this application, the present study evaluates the biodegradation behavior of these materials in soil and describes the substantial improvements in sustainability that result from the additional functions (intrinsic fertilizer and root improvement of plants) and the end-of-life option of biodegradation. After being buried in soil for designated time intervals, the residual degraded samples were analyzed to determine morphological and thermal properties at sequential stages of biodegradation. Samples were characterized by scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The results indicated that there was a compatible system between SP.A and PLA in the melt. Incorporation of SP.A accelerated the biodegradation rate of this binary blend significantly compared with pure PLA. Prior to the degradation process, both the glass transition temperatures and melting temperatures of the blends containing SP.A decreased as the concentration of the soy protein increased. With increasing degradation time of the blended samples in soil, the glass transition temperatures increased in the early stages of biodegradation then decreased, a trend associated with the decrease in the molecular weight of the blends as a result of biodegradation. In addition, the thermal stability of blends increased gradually with increasing degradation time, suggesting faster biodegradation loss of the soy component of the SP.A/PLA blends. These results support the use of soy-based polymer blends for horticulture crop containers and provide data for evaluating their use as sustainable materials for other potential applications. Disciplines ABSTRACTOne of the most significant limitations to widespread industrial implementation of emerging bioplastics such as poly(lactic acid) and poly(hydroxyalkanoate) (PHA) is that they do not match the flexibility and impact resistance of petroleum-based plastics like poly(propylene) or highdensity poly(ethylene). The basic goal of this research is to identify alternative, affordable, sustainable, biodegradable materials that can replace petroleum-based polymers in a wide range of industrial applications, with an emphasis on providing a solution for increasing the flexibility of PHA to a level that makes it a superior material for bioplastic nursery-crop containers. A series of bio-based PHA/poly(amide) (PA) blends with different concentrations were mechanically melt processed using a twin-screw extruder and evaluated for physical characteristics. The effects of blending on viscoelastic properties were investigated using smallamplitude oscillatory shear flow experimen...

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Section: Resultsmentioning

confidence: 99%

Characterization and biodegradation behavior of bio-based poly(lactic acid) and soy protein blends for sustainable horticultural applications

et al. 2015

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“…X c was ascertained by eq. (1), considering a melting enthalpy of 142 J/g for 100% crystalline PHB as cited in the literature

X_{c} = \frac{Δ H_{m}}{W_{p} \times Δ H_{m 100 %}} \times 100 %

where X c is the crystallinity (%), Δ H m is the melting enthalpy of the polymer (J/g), W p is the proportion of the polymer in the blend, and Δ H m100% is the melting enthalpy of the 100% crystalline polymer.…”

Section: Resultsmentioning

confidence: 99%

Processing and characterization of bio‐based poly (hydroxyalkanoate)/poly(amide) blends: Improved flexibility and impact resistance of PHA‐based plastics

Yang

Madbouly

Schrader

et al. 2015

J of Applied Polymer Sci

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One of the most significant limitations to widespread industrial implementation of emerging bioplastics such as poly(lactic acid) and poly(hydroxyalkanoate) (PHA) is that they do not match the flexibility and impact resistance of petroleum-based plastics like poly(propylene) or high-density poly(ethylene). The basic goal of this research is to identify alternative, affordable, sustainable, biodegradable materials that can replace petroleum-based polymers in a wide range of industrial applications, with an emphasis on providing a solution for increasing the flexibility of PHA to a level that makes it a superior material for bioplastic nursery-crop containers. A series of bio-based PHA/poly(amide) (PA) blends with different concentrations were mechanically melt processed using a twin-screw extruder and evaluated for physical characteristics. The effects of blending on viscoelastic properties were investigated using small-amplitude oscillatory shear flow experiments to model the physical character as a function of blend composition and angular frequency. The mechanical, thermal, and morphological properties of the blends were investigated using dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, and tensile tests. The complex viscosity of the blends increased significantly with increasing concentration of PHA and reached a maximum value for 80 wt % PHA blend. In addition, the tensile strength of the blends increased markedly as the content of PHA increased. For blends containing PA at >50 wt %, samples failed only after a very large elongation (up to 465%) without significant decrease in tensile strength. The particle size significantly increased and the blends became more brittle with increasing concentration of PHA. In addition, the concentration of the PA had a substantial effect on the glass relaxation temperature of the resulting blends. Our results demonstrate that the thermomechanical and rheological properties of PHA/PA blends can be tailored for specific applications, and that blends of PHA/PA can fulfill the mechanical properties required for flexible, impact-resistant bio-based nursery-crop containers.

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“…Often the temperature at which 5% (T 5% ) or 10% (T 10% ) mass loss is reached (in relation to the initial mass) is taken as a measure of thermal stability. Thermal stability examinations are conducted under neutral atmosphere (nitrogen, oxygen), oxidizing atmosphere (oxygen, air) or under other gases, e.g., carbon dioxide [19].…”

Section: Introductionmentioning

confidence: 99%

“…Especially interesting seems to be the use of DTA and DSC techniques in the examination of polymers' thermal and oxidation stability. The TGA technique determines the relation of the mass of the sample to the steadily increasing temperature, and to the time of the sample heating in constant temperature [19].…”

Section: Introductionmentioning

confidence: 99%

Thermal Properties of Polyurethane-Polyisocyanurate (PUR-PIR) Foams Modified with Tris(5-Hydroxypenthyl) Citrate

Liszkowska¹,

CzupryÅski²,

Paciorek‐Sadowska³

2016

J Adv Chem Eng

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The influence of 4,4’-bis(6-hydroxyhexoxy)biphenyl moieties on properties of polyurethanes based on 4,4’-methylenebis(cyclohexyl isocyanate)

Cited by 4 publications

References 18 publications

Characterization and biodegradation behavior of bio-based poly(lactic acid) and soy protein blends for sustainable horticultural applications

Characterization and biodegradation behavior of bio-based poly(lactic acid) and soy protein blends for sustainable horticultural applications

Processing and characterization of bio‐based poly (hydroxyalkanoate)/poly(amide) blends: Improved flexibility and impact resistance of PHA‐based plastics

Thermal Properties of Polyurethane-Polyisocyanurate (PUR-PIR) Foams Modified with Tris(5-Hydroxypenthyl) Citrate

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