The Influence of Diphenyl Siloxane on Morphology and Physical Properties in the Poly(Imide Siloxane)(PIS) Copolymer

Liaw, Wen-Chang; Chen, Kuan-Pin

doi:10.1007/s10965-006-9074-6

Cited by 12 publications

(8 citation statements)

References 19 publications

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“…In our previous reports, [23][24][25] it was found that when the content of PDMS (minor component) in PIS copolymers was higher than 2.7 mol % (prepared from the diamine mixture of APPS and 2, 2 0 -bis[4-(3-aminophenoxy) penyl] sulfone (m-BAPS) to condensate with 3,3 0 ,4,4 0 -Benzophenenone tetracarboxyilc dianhydride (BTDA)), microphase separation between PI and PDMS segments was detected. This could be attributed to the large difference of solubility parameters between these two homopolymers.…”

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confidence: 85%

A Straightforward Synthesis and Characterization of a New Poly(imide siloxane)-based Thermoplastic Elastomer

Liaw

Chang-Chien

Kang

et al. 2007

Polym J

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Three series of poly(imide siloxane) (PIS) copolymers were synthesized through straightforward simultaneous condensation reaction of pyromellitic dianhydride (PMDA), 2, 2 0 -bis [4-(3-aminophenoxy)phenyl] sulfone (m-BAPS) and three different number-average molecular weights (M n ¼ 859, 1152 and 1619 gÁmol À1 ) of , !-bis (3-aminopropyl) polydimethyl siloxane (APPS). The effects of hard segment, polyimide (PI), on the properties of PIS copolymers were investigated. The prepared PIS copolymers possess the properties of thermal plastic elastomers. Microphase separation, affected by formulation, was found to be important phenomenon that determined the physical properties of the PIS copolymer. Mechanical measurement with the Instron-type tensile meter showed that the copolymers have elongation at break of up to 324%. Two prepared samples (APPS M n ¼ 859, PI content of 15 and 20 wt %) were found to exhibit good rubber property of being able to retract to original length upon release of the stress applied, others were characterized as plastics. The softening temperatures of the PIS thermoplastic elastomers ranged from 109 to 265 C, and can easily be processed by extrusion or injection molding, and recycled.KEY WORDS: Polysiloxane / Poly(imide siloxane)(PIS) / Copolymer / Thermoplastic Elastomer (TPE) / Microphase Separation / In the field of rubber industry, thermoplastic elastomer (TPE) is a group of polymeric materials that exhibit elastomeric behavior at their service temperature and can be reprocessed by melting at elevated temperatures.1,2 Hence TPE is considered a recyclable material. Diminishing supply of materials and energy from nature has become increasingly severe. The urgency in the demand for recyclable and energy efficient materials has become increasingly high through the years. When comparing to conventional vulcanized rubber, TPE not only exhibits elasticity, but also provides energy saving processibility which is similar to injection moldable plastics. TPE can be recycled by simple melt mixing and extrusion and/or injection, and the process can be fully automated.Polysiloxane rubbers have polymeric Si-O-Si backbone, which renders the material distinctive properties, such as good electric property, thermal stability, anti-oxidative property, durability at low temperatures, as well as ozone, weathering and radiation resistance.3 Although polysiloxane rubber has wide applications in the electronic, tubing and baby care industries, especially in the manufacturing of keyboards, the TPE of polysiloxane system has not yet been widely commercialized.Mostly, the manufacture of polysiloxane rubber adopts one of the following processes. The first process is the widely used high temperature vulcanized process (HTV), in which the polysiloxane gum of high molecular weights were mixed and vulcanized with peroxide, reinforce filler and other additives prior to hot compress molding. The second was the twocomponent room temperature vulcanized process (RTV-2), in which a separately pre-measured amount of highly reactive...

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confidence: 85%

A Straightforward Synthesis and Characterization of a New Poly(imide siloxane)-based Thermoplastic Elastomer

Liaw

Chang-Chien

Kang

et al. 2007

Polym J

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“…This limiting content of polysiloxane was found to be a function of the partial molecular weight of the polysioxane segment. [16][17][18] A solution to reducing the degree of microphase separation has been developed by attaching phenyl groups to the polysiloxane backbone to increase the compatibility between the two segments. 18 By doing so, the limiting content of polysiloxane was increased to 5 wt % without significant degree of microphase separation.…”

Section: Resultsmentioning

confidence: 99%

“…Due to the inherent large difference of the solubility parameters of PDMS and PI (the soft and hard segments), microphase separation is bound to exist in most PIS copolymers. [16][17][18] According to our previous experience in synthesizing PIS, the degree of microphase separation is mainly affected by the molecular weight of the polysiloxane and its weight percent. 16,17 However, we found that the microphase separation could be manipulated by changing the attached organic group on the polysiloxane, which in turn, could improve the compatibility between the PI and the polysiloxane segments.…”

Section: Morphologymentioning

confidence: 99%

“…When part of the dimethyl groups of PDMS segment in the PIS copolymers were substituted with diphenyl groups (,!-diaminopropyl poly(dimethyl-co-diphenyl)siloxane, APPPS), the degree of microphase separation were decreased. 18 In previous cases of PIS copolymers, the PI segment was the major component while polysiloxane was used at relatively minor amount (polysiloxane in PI). When polysiloxane is presented in the PIS copolymer as the major component (PI in polysiloxane), the whole situation might be different, due to the distinctly different chemical nature of the two segments as reflected on the solubility parameters.…”

Section: Morphologymentioning

confidence: 99%

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SiO2 Reinforcement and Morphology of a Novel Poly(imide-siloxane)-Based Thermal Plastic Elastomer Composite

et al. 2009

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Silica (SiO 2 ) was used for the reinforcement of the poly(imide-siloxane) (PIS)-based thermal plastic elastomer. Trimethylsilyl modified SiO 2 was incorporated in the copolymer matrix to obtain the PIS/SiO 2 composties. In preparing the PIS/SiO 2 composite, the modified MeOH/THF solvent system provided a homogeneous reaction environment by offering good solubilities for the reactants and the intermediates while facilitating the dispersion of SiO 2 . The trimethylsilyl group modified fume silica offered excellent interfacial compatibility and kept the microphase separation at desirable level. SEM studies showed that such surface modification improved the dispersion of SiO 2 in the copolymer matrix. Morphological and thermal studies revealed the likelihood of a spatial rearrangement of the long chain alternating pyromellitic dianhydride/ polydimethyl siloxane (PMDA/PDMS) soft segments leading to a macroscopically homogeneous composite. Such spatial rearrangement further stabilized the microphase separation which is necessary for exhibiting TPE characteristics. The obtained composites have better thermal and mechanical properties than bare PIS copolymer. An elongation at break of 989% was obtained for the PIS/SiO 2 composite at silica content of 3 wt %.KEY WORDS: PIS Copolymer / Composite / Thermal Plastic Elastomer / SiO 2 Reinforcement / Morphology / Thermoplastic elastomers (TPE) are a group of materials that possess elasticity. The elasticity of a TPE is comparable to that of covalent bond crosslinked rubbers, and its meltability allows for repeated processing from melt in a way analogous to common plastics (e.g., by extrusion or injection molding). The chemical constituent of a TPE is generally a tri-block (or multiblock) copolymer, which usually provides a soft segment in the center and the hard segments in the bi-terminal portions of the coplymer. Typical examples are SBS (styrene-butadienestyrene block copolymer), SEBS (styrene-ethylene-butadienestyrene block copolymer) and TPU (thermoplastic polyurethane).1,2 In the development of new types of TPE, the chemical ingredients of the soft and hard segment as well as their spatial arrangement are important design variables for the success of their potential applications.The hard segment is one of the key components of TPE, which provides the physical crosslink points by strong intermolecular attraction when used at working temperature, but such intermolecular attraction can be reversibly dislodged by melting at high temperature. To function as the hard segment, the component polymer (or inorganic physical crosslinkers) should be easily solidified or crystallized, and at the same time, being limitedly compatible with the soft segment to maintain, at desirable level, the necessary microphase separation during copolymerization with the soft segments. Polyimides (PI) is a group of polymers and some members of PI possess such property, and have been identified as a good choice for the hard segment of TPEs. 3,4 Kricheldorf et al.3 synthesized poly(ether-ester-imides...

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“…However, the absorption peaks of the phenyl groups on diphenylsiloxane coincided with that on the PI block, therefore, it is not possible to distinguish between the two on the spectra. Although the role of diphenylsiloxane in the hybrid copolymer awaits to be cleared, it is discussed in detail in another report 36 and data in this respect will not be included in this study. However, we did experience the benefits that came from the addition of diphenylsiloxane.…”

Section: Ftir Analysismentioning

confidence: 99%

Preparation and properties of poly(imide siloxane) segmented copolymer/silica hybrid nanocomposites

Liaw

Chen

2007

J of Applied Polymer Sci

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A series of Poly(imide siloxane) (PIS)/silica (SiO2) hybrid nanocomposites with C‐Si covalent bonding between the homogeneous PIS copolymer and SiO2 have been successfully synthesized. The PIS copolymer synthesized in this study is characterized by the coexistence of two segments: the polyimide segment and polydimethyldiphenylsiloxane segment, and the latter are specially featured with the introduction of a diphenyl group for improved homogeneity. The PIS/SiO2 hybrid nanocomposites were prepared from 3,3′,4,4′‐bezonphenone tetracarboxylic dianhydride (BTDA), 2‐2′‐bis[4(3‐aminophenoxy)phenyl] sulfone (m‐BAPS), and vinyl‐containing α,ω‐bis‐(aminopropyl)polydimethyldiphenyl siloxane (APPPVS) oligomer to form vinyl siloxane‐containing poly(amic acid) (PAAVS). This copolymer was further reacted with trimethoxyvinylsilane (TMVS), 2,2′‐azobis‐isobutyronitrile (AIBN), and tetraethoxysilane (TEOS). The PIS/SiO2 hybrid nanocomposites exhibited a series of properties unlike traditional composites, and the nano sized inorganic particles have resulted in a transparent hybrid when the SiO2 content was less than 12 wt %. The Young's modulus and tensile strength of the PIS/SiO2 hybrid nanocomposites increased with increasing SiO2 content, whereas, the elongation at break was only slightly affected. The structure of the hybrids was characterized by FTIR, 29Si‐NMR, 1H‐NMR, and 13C‐NMR, as well as SEM and TEM. The thermal properties of the PIS/SiO2 hybrid nanocomposites were investigated with DSC, TGA, and DMA studies. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007

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The Influence of Diphenyl Siloxane on Morphology and Physical Properties in the Poly(Imide Siloxane)(PIS) Copolymer

Cited by 12 publications

References 19 publications

A Straightforward Synthesis and Characterization of a New Poly(imide siloxane)-based Thermoplastic Elastomer

A Straightforward Synthesis and Characterization of a New Poly(imide siloxane)-based Thermoplastic Elastomer

SiO2 Reinforcement and Morphology of a Novel Poly(imide-siloxane)-Based Thermal Plastic Elastomer Composite

Preparation and properties of poly(imide siloxane) segmented copolymer/silica hybrid nanocomposites

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