Polyester: Properties, Preparation and Applications Edited by Hina Yamashita and Yui Nakano


Polyester: Properties, Preparation and Applications
Edited by Hina Yamashita and Yui Nakano

Polyester Properties, Preparation and Applications

Preface vii
Chapter 1 Hydrolysis of Polyesters and Polycarbonates 1
Toshiaki Yoshioka and Guido Grause
Chapter 2 Multiwall Carbon Nanotube Reinforced
Polyester Nanocomposites 33
Jun Young Kim and Seong Hun Kim
Chapter 3 Recent Developments in Modification
of Cyanate Ester Resins 109
A. Fainleib and O. Grigoryeva
Chapter 4 Biodegradable Aliphatic Polyesters Derived
from 1,3-Propanediol: Current Status and Promises 147
George Z. Papageorgiou and Dimitrios N. Bikiaris
Chapter 5 Compatibility of Cotton/Nylon and Cotton/Polyester
Warp-Knit Terry Towelling with Industrial
Laundering Procedures 175
Adine Gericke, L. Viljoen and R. de Bruin
Chapter 6 Development of Polyester Type Shape Memory
Polymer and Its Application to Composite Material 187
Yong-Chan Chung, Byoung Chul Chun,
Mi-Hwa Chung, Yong-Sik Shim and Jae Whan Cho
Chapter 7 Degradation of Aromatic Co-Polyesters Derived from
N-Oxybenzoic, Tere- and Isophthalic Acids and Dioxydiphenyl 215
E. V. Kalugina, K. Z. Gumargalieva and V. G. Zaikov
Chapter 8 Thermal Stability and Fire Performance of
Unsaturated Polyester Resins 225
E. Kicko-Walczak
Index 235

Polyester (aka Terylene) is a category of polymers which contain the ester functional group in their main chain. Although there are many forms of polyesters, the term “polyester” is most commonly used to refer to polyethylene terephthalate (PET). Other forms of polyester include the naturally-occurring cutin of plant cuticles as well as synthetic polyesters such as polycarbonate and polybutyrate.

Polyester may be produced in numerous forms. For example, polyester as a thermoplastic may be heated and processed into different forms and shapes, e.g., fibers, sheets and threedimensional shapes. While combustible at high temperatures, polyester tends to shrink away from flames and self-extinguishes.

This book provides leading edge research on this field from around the globe. Chapter 1 – Processes were developed in recent years in order to recover raw materials from poly(ethylene terephtalate) (PET) and polycarbonate (PC) by hydrolysis. The main focus was the recovery of terephthalic acid and ethylene glycol besides other products such as benzene, salts of terephthalic acid and oxalic acid. Processes developed for PET are also valid for polyesters such as poly(butylene terephthalate) (PBT) and poly(ethylene 2,6-napthalene dicarboxylate) (PEN). The recovery of bisphenol-A (BPA) from PC requires more sophisticated methods due to the low stability of BPA at high temperatures. Often phenol and isopropenyl phenol are obtained as degradation products of BPA.

Chapter 2 – This chapter presents the preparation of polymer nanocomposites and the effects of multiwall carbon nanotube (MWCNT) on the structure and properties of poly(ethylene 2,6-naphthalate) (PEN) nanocomposites. The combination of a very small quantity of expensive MWCNT with conventional cheap thermoplastic polymers provides attractive possibilities for improving the physical properties of polymer composites using a cost-effective method, from a commercial perspective. MWCNT-reinforced PEN nanocomposites were prepared by a melt blending process in a twin screw extruder to create advanced materials for possible practical applications in numerous industrial fields. There are significant dependence of the crystallization behaviors and their kinetics of the PEN/MWCNT nanocomposites on the MWCNT content, the cooling rate, and the crystallization temperature. The MWCNT in the PEN nanocomposites exhibited much higher nucleation activity than any nanoreinforcing filler. In the PEN/MWCNT nanocomposites, the incorporation of the MWCNT promoted the nucleation and the growth with higher crystallization rate of the PEN/MWCNT nanocomposites, and simultaneously reduced the fold surface free energy and the works required in folding macromolecular chains in the PEN/MWCNT nanocomposites. The non-terminal behavior observed in the PEN/MWCNT nanocomposites was related to the dominant nanotube-nanotube interactions at higher MWCNT content, leading to the formation of the interconnected or network-like structures of the MWCNT in the PEN nanocomposites. The incorporation of very small quantity of the MWCNT significantly improved the mechanical properties of the PEN/MWCNT nanocomposites. There is a significant dependence of the thermal stability and degradation behavior of the PEN/MWCNT nanocomposites on the MWCNT content and heating rate. The interconnected network-like structures of the MWCNT resulted in the physical barrier effect against thermal degradation both by retarding the rate of thermal degradation and by hindering the transport of volatile decomposed products in the PEN nanocomposites, leading to the improvement in the thermal stability of the PEN/MWCNT nanocomposites. This Chapter attempts for the first time to summarize the preparation, the non-isothermal crystallization kinetics, the crystallization and melting behavior, the rheological and mechanical properties, the thermal stability, and the thermal degradation kinetics of MWCNT-reinforced PEN nanocomposites.

Chapter 3 – Cyanate Ester Resins (CER) offer a variety of excellent thermal and good mechanical properties, which commend them for use in high performance technology (e.g. as matrices for composites for high-speed electronic circuitry and transportation). The product of CER curing process polycyanurates (PCN) are synthesized by a catalytic high temperature polycyclotrimerization reaction of cyanate esters of bisphenols For the electronics market, attractive features of PCN are their low dielectric loss characteristics, dimensional stability at molten solder temperatures (220-270°C), high purity, inherent flame-retardancy (giving the potential to eliminate brominated flame retardants) and excellent adhesion to conductor metals at temperatures up to 250°C . Since the late 1970s, cyanate ester resins have been used with glass or aramid fibers in high-speed multilayer circuit boards and this remains their primary application. Several reviews collecting the numerous publications (papers and patents) in the field of PCN synthesis, processing, characterization, modification and application have appeared since 1990s. In addition, like conventional FR-4 diepoxides, cyanate ester laminates retain the desirable (ketone) solution processing characteristics and the ability to be drilled, making possible to employ them in printed circuit board manufacture. In the last three decades, aerospace composites have evolved into damage-tolerant primary and secondary structures utilizing both thermoset and thermoplastic resins. PCN homopolymers develop approximately twice the fracture toughness of multifunctional epoxies while qualifying for service temperatures of at least 150°C, intermediate between epoxy and bismaleimides capabilities. PCN have already flown in prototype radomes and high gain antennae, with possible applications in primary and secondary structures of the High Speed Civil Transport (HSCT) and European Fighter Aircraft. PCN are also being qualified for satellite truss and tube structures and cryogenic, radiation-resistant components in the Superconducting Supercollider. This is indeed the problem, to convince a traditionally conservative industry that the superior performance of PCN (which surpass the glass transition temperature and hydrophobicity of epoxies while matching their processability and are easily toughened) makes them worthy of further investigation in spite of their price, which is currently higher than the price of the epoxies. PCN must be traditionally cured at high temperatures in order to achieve complete conversion, which increases manufacturing cost, but reactive modification of PCN allows decreasing the high temperature of PCN post-curing. The primary drawback of PCN, which hinders more extensive application of the cured materials, however, is low room temperature toughness..

Chapter 4 – Among biodegradable polymers, polyesters derived from aliphatic dicarboxylic acids and diols are of special importance. Polyesters of 1,3-propanediol were overlooked till recently, since the specific monomer was not available in the quantities and price that might enable production of polymers. However, in recent years more attractive processes have been developed for the production of 1,3-propanediol from renewable resources. Nowadays, research on biodegradable poly(1,3-propylene alkanedioate)s, such as poly(propylene succinate) (PPSu), poly(propylene adipate) (PPAd) and poly(propylene sebacate) (PPSe), has gained increasing interest, due to their fast biodegradation rates and their potential uses in biomedical or pharmaceutical applications, such as drug delivery systems. The odd number of methylene units in the diol segment is responsible for the lower melting points, lower degree of crystallinity and higher biodegradation rates of the specific polymers compared with their homologues based on ethylene-glycol or 1,4-butanediol. In this chapter synthesis and properties of the 1,3-propanediol based aliphatic polyesters and especially their biodegradation characteristics are reviewed. Specific attention has been paid to preparation of related copolymers and blends with other important polymers, since these techniques may offer routes for optimizing properties and producing tailor-made materials. Copolymerization of 1,3-propanediol with mixtures of aliphatic or even aromatic acids, leads to linear polyesters with improved or balanced biodegradation and mechanical properties. Blends with other biodegradable polymers have been studied recently. Finally, potential pharmaceutical applications of poly(1,3-propylene alkanedioate)s as solubilizing and stabilizing carriers for drugs are exemplified.

Chapter 5 – Large institutions, such as hotels and hospitals, often use specialized industrial laundries for laundering sheets, towels or uniforms. The main purpose of this study was to determine the effect of industrial laundering procedures on the durability of cotton warp knitted towels with a synthetic ground structure of either nylon or polyester. The durability of cotton/nylon and cotton/polyester terry towelling fabric samples that were subjected to repeated industrial laundering procedures, was compared by measuring the tensile strength of fabric samples after 50 washing cycles and 50 washing/tumble-drying cycles. The difference between the tensile strengths of the cotton/polyester and cotton/nylon terry towelling samples after washing alone was not significant. The tensile strength of the cotton/nylon samples, however, was significantly less than that of the cotton/polyester samples after tumble-drying. It was concluded that industrial laundering procedures, especially tumble-drying, have a more detrimental effect on the durability of the nylon ground structure than on the polyester ground structure of warp-knitted terry towelling fabrics.

Chapter 6 – Polyester type shape memory polymers were synthesized to improve their mechanical and shape memory properties and used for the preparation of sandwich type composite materials. Especially, poly(ethylene terephthalate) (PET) and poly(ethylene glycol) (PEG) copolymers with shape memory ability were prepared. After selecting the best composition of PET-PEG copolymer in mechanical properties, cross-linking agent such as glycerine, sorbitol, or maleic anhydride (MAH) was included for cross-linked copolymer, followed by analysis of its effect on mechanical, shape memory, and damping properties. The highest shape recovery was observed for copolymer with 2.5 mol% of glycerine, and the best damping effect indicating vibration control ability was from copolymer with 2.5 mol% of sorbitol. With the optimum copolymers in hand, sandwich-structured epoxy beam composites fabricated from epoxy beam laminate and cross-linked PET-PEG copolymer showed that impact strength increased from 1.9 to 3.7 times depending on the type of copolymer, and damping effect also increased as much as 23 times for the best case as compared to epoxy laminate beam alone. PET-PEG copolymers cross-linked with glycerol and sulfoisophthalate (SP) were also prepared to investigate the feasibility of vibration-control of composite laminate by additional ionic interaction. Composition of glycerol and SP was varied in order to get a copolymer with the best mechanical and shape memory properties. The highest shape recovery was observed for the copolymer with 2.5 mol% of glycerol and 2.5 mol% of SP. The sandwich-type copolymer composite showed improved impact strength (3.5 times) and damping effect (2.6 times) as compared to epoxy laminate beam alone. The resultant sandwich-structured epoxy beam composite can be utilized as structural composite material with vibration control ability and its glass transition temperature can be controlled by adjustment of hard segment content and cross linking agent composition.

Chapter 7 – Special attention to these polymers is defined by their specific feature, which is orientation in the melt, mostly associated with the intense development in computer technologies. Owing to this property such polymers are devoted to the “family” of liquidcrystal polymers. The liquid-crystal properties are also observed for PAI with an uneven number of CH2-groups.It should be noted that polyalkanimide (PA-12), discussed in, also displays liquid-crystal properties under definite processing modes.

Liquid-crystal aromatic copolyesters (LCP) were studied. They were derived from dioxydiphenyl diacetate, acetoxybenzoic, iso- and terephthalic acids (IPA and TPA, respectively): 100/0, 75/25, 50/50, 25/75, 0/100

Chapter 8 – The thermal decomposition of halogenated and non-halogenated unsaturated polyester resins (UPR`s), fire retarded by zinc hydroxystannate (ZHS) and cross-linked with styrene, has been investigated by thermogravimetry (TG) and TG coupled on-line with Fourier transform infra red spectroscopy (TG-FTIR) or mass spectroscopy (TG-MS).

In this Chapter, thermal analysis of the decomposition process has been performed – hence, the flame retardancy and thermal stabilization of halogenated and non- halogenated polyester resins by ZHS may be explained by the formation of surface-localized spherical barriers which are growing according to the nucleation growth mechanism and which attenuate the transfer of heat from the decomposition zone to the substrate. This effect was found as dominating in the flame-retardancy mode of action.

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