A reactive melt modification of polyethylene terephthalate

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1.2 Applications and Limitations of Commercially Available PET 1.2.1 Applications Principal commercial products of PET are fibers, bottles, and films. Among them, commodity fibers have provided the largest outlet for its consumption (Rodriguez, 1996). The current growth rate for PET bottles is around 15% whereas for fibers it is less than 5%. Films have always been relatively small in production volume (about 10% of total PET), but they are used in high value added applications, such as audio and videotapes. There is one noteworthy difference between the method PET filaments and fibers are produced and that used for producing PET sheets, films, or bottles (Gupta and Bashir, 2002). With filaments and fibers, direct shape forming is possible from the melt, while with films and bottles it is essential to first make an amorphous intermediate (sheet or preform) by quench cooling from the melt. Then the intermediate is softened by heating to a temperature —20-30°C above the glass transition temperature - T g, when it has enough strength to support itself but is pliable enough to be biaxially oriented. The combination of this two step process is called as injection-stretch-blow molding. Direct biaxial stretching of the melt is possible with polyolefins, but not with most of the PET resins because of their low melt elasticity/strength. Therefore, conventional film blowing and extrusion blow molding techniques, where biaxial stretching is applied to the melt,
7 are not suitable for most of the commercially available PET resins (Dealt' and Wissbrun, 1990). In conventional forming processes, bottles could either be made using injection blow molding or stretch blow molding operations (Dealy and Wissbrun, 1990). As shown in the injection blow molding schematic in Figure 1.4 (b), a tube of molten polymer, the parison or preform produced by injection molding as per Figure 1.4 (a), is sealed at both ends and held in place while two halves of a hollow mold surround it (Rodriguez, 1996). Air is injected into the parison or preform, which blows in as if it were a rubber balloon. When the polymer surface meets the cold metal wall of the mold, it is cooled rapidly below T g or Tm , depending on whether the polymer is amorphous or crystalline. Once the product is dimensionally stable, the mold is opened, the bottle is ejected, a new parison is introduced, the mold is closed, and so on. In the case of stretch blow molding shown in Figure 1.5, in addition, to the above sequence, biaxial orientation in the bottle is increased by longitudinal stretching during radial blowing with the help of an internal rod (Rodriguez, 1996). There are two crucial phenomena that are related to the blow molding process (Dealy and Wissbrun, 1990). The melt deformation that occurs in the die generates molecular orientation, which manifests itself at the die exit as `parson swell'. Swell during blow molding is known to depend upon MW, the extent of branching, and/or molecular weight distribution (MWD). 'Sag' (drawdown), another important parameter, can cause large variations in thickness and diameter along the parison, and in an extreme case can cause the parison to break off. Sag is generally quantitatively related to the melt flow index of the polymer. PET in the melt state, cannot support its own weight long
Page 1 and 2: Copyright Warning & Restrictions Th
Page 3 and 4: ABSTRACT REACTIVE MELT MODIFICATION
Page 5 and 6: REACTIVE MELT MODIFICATION OF POLYE
Page 7 and 8: BIOGRAPHICAL SKETCH Author: Rahul R
Page 9 and 10: Copyright © 2003 by Rahul Ramesh D
Page 11 and 12: ACKNOWLEDGEMENTS I always considere
Page 13 and 14: TABLE OF CONTENTS Chapter Page 1 IN
Page 15 and 16: TABLE OF CONTENTS (Continued) Chapt
Page 17 and 18: LIST OF FIGURES Figure Page 1.1 Mac
Page 19 and 20: LIST OF FIGURES (Continued) Figure
Page 21 and 22: LIST OF FIGURES (Continued) Figure
Page 23 and 24: Striation Thickness Time Diffusion
Page 25 and 26: tertiary amine terephthalic acid th
Page 27 and 28: CHAPTER 1 INTRODUCTION After its in
Page 29 and 30: 3 of 0.5-1.00 mm Hg (Sorenson 2001)
Page 31: where rib is the solution viscosity
Page 35 and 36: 9 In the case of sheet applications
Page 37 and 38: 11 operation (Dealy and Wissbrun, 1
Page 39 and 40: 13 During the cell growth phase of
Page 41 and 42: 15 suitability of extruders as cont
Page 43 and 44: 17 conditions and additive concentr
Page 45 and 46: 19 understand the effect of evolvin
Page 47 and 48: CHAPTER 3 LITERATURE REVIEW This ch
Page 49 and 50: 23 absence of modifiers is accompan
Page 51 and 52: 25 The primary objective while modi
Page 53 and 54: 27 Polypropylene resins with high m
Page 55 and 56: 29 initially the reaction with hydr
Page 57 and 58: 31 A diglycidyl ether, often in the
Page 59 and 60: 33 Characterizing the products of t
Page 61 and 62: 35 5. Ease of mixing in the polymer
Page 63 and 64: 37 Figure 3.4 Epoxy or 0xirane ring
Page 65 and 66: 39 carbocation stability overrides
Page 67 and 68: 41 Figure 3.9 Anhydride — epoxy r
Page 69 and 70: 43 Figure 3.12 Base catalyzed hydro
Page 71 and 72: 45 activity to enhance the PET-epox
Page 73 and 74: 47 4.1.2 Chain EDtenders The struct
Page 75 and 76: TGDDM was used in the batch mixer s
Page 77 and 78: 51 4.2 Processing and Characterizat
Page 79 and 80: 53 specimens as a function of freVu
Page 81 and 82: 55 to the parallel plates). An addi
Page 83 and 84:
57 background spectrum. It took app
Page 85 and 86:
CHAPTER 5 RESULTS AND DISCUSSION Th
Page 87 and 88:
61 molecular weight of MPET as also
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63 rate expressions analogous to th
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Figure 5.5 Possible reactions betwe
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67 taking place by the convective;
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69 5.1.4 Comparison of Epoxides Fig
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71 5.1.5 Reactions of TGIC with HPE
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73 Figure 5.11 shows the vanation o
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75 Figure 5.13 shows the effect of
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77 to time. In a general sense, the
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79 5.1.7 Study on Role of Catalysts
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81 groups adjacent to the tertiary
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83 overall less activity towards TG
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85 5.2.1 Typical Batch MiDing Runs
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87 It appears that the higher proce
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89 injection (Dealy and Wissbrun, 1
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91 rheological power scaling law fo
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93 In the calculations, the freVuen
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95 whereas H(?.) of the unmodified
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97 However, the disintegration of t
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99 the Section 4.1.3. As evident fr
Page 127 and 128:
101 changes in dynamic moduli and m
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103 In the case of 270 °C, the mod
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105 accessibility of unreacted grou
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107 believed to be charactenzed by
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109 increase in the melt elasticity
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111 In general, for crosslinked sys
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113 crosslinked gels in swelling eV
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115 formation of epoxy/PET reaction
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117 A seVuential reactive extrusion
Page 145 and 146:
CHAPTER 6 CONCLUSIONS AND RECOMMEND
Page 147 and 148:
121 of PET by the selected tnepoxid
Page 149 and 150:
REFERENCES S. Abe and M. Yamaguchi,
Page 151 and 152:
125 L. M. Dossin and W. W. Graessle
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127 P. Huang, Z. Zhong, S. Zheng, W
Page 155 and 156:
129 J. Meissner and J. Hostettler,
Page 157 and 158:
131 T. Shiwaku, K. Hijikata, K. Fur
Page 159 and 160:
133 M. Xanthos and S. K. Dey, "Foam
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A reactive melt modification of polyethylene terephthalate

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