Side-chain liquid crystal polymers of 2,3-disubstituted norbornenes via ring-opening metathesis polymerization, 2. Methoxybiphenyl as mesogenic group,influence of flexible spacer length m = 4 to 10 on the thermotropic behaviour

We report the synthesis and ring-opening metathesis polymerization of (±)-exo,endo-bis[ω-(4′-methoxybiphenyl-4-yloxy)alkyl] bicyclo[2.2.1]-hept-5-ene-2,3-dicarboxylates using the molybdenum-carben initiator Mo(CH-t-Bu)(NAr)(OCCH₃)(CF₃)(₂)₂ with NAr = 2,6-diisopropylaniline. The spacer length was varied from m = 4 to 10 methylene groups. All monomers and polymers show mesophases of the smectic type. Independently of the spacer length no glass transition was detected. An odd-even effect of transition temperatures was observed for both the monomers and polymers. The monomers with m > 5 showed more phase transitions in the DSC-heating runs. Dependency of liquid crystalline transition temperatures on molecular weight is shown for one polymer (m = 6). Transition temperatures are roughly constant for polymers consisting of more than 30 repeating units. In contrast, the enthalpy changes of these transitions are nearly independent of the molecular weights once the polymers contain more than 10 repeating units, but they are strongly dependent on spacer length, with a minimum at m = 6.     

Transitional properties of liquid-crystalline side-chain polymers derived from poly(p-hydroxystyrene)

A series of liquid-crystalline polystyrene derivatives with ω-(4-(4-fluorophenylazo)phenoxy)-alkoxy pendant groups have been synthesized and characterized. Homologues with four or more methylene units in the spacer chain exhibit smectic liquid-crystalline phases, while the homologue with three methylene units forms an amorphous glass. The smectic A-isotropic (S_A-I) transition temperatures show a marked odd-even effect as a function of the parity of the spacer chain. This odd-even behaviour is also found in the variation of ΔS/R at the S_A-I transition across the series. A marked hysteresis between the transition temperatures determined on heating and the transition temperatures determined on cooling is observed. A molecular interpretation of these phenomena is proposed.     

Liquid crystalline polymers containing heterocycloalkanediyl groups as mesogens, 1. Liquid crystalline polymethacrylates and polyacrylates containing 1,3-dioxane-2,5-diyl groups as mesogens in the side chain

Polymethacrylates and polyacrylates containing 4-[5-(4-methoxyphenyl)-1,3-dioxan-2-yl]-phenol moieties as mesogenic units and an aliphatic spacer containing eleven methylene units were synthesized. Their phase behavior was studied by differential scanning calorimetry and optical polarizing microscopy, and compared with the phase behavior of the corresponding polymethacrylates and polyacrylates containing 4′-methoxy-4-biphenylol as mesogens. All polymers present smectic mesomorphism. The substituted 2,5-diphenyl-1,3-dioxane mesogen resembles a terphenyl mesogen in which the internal phenyl ring is hydrogenated. Even so, when compared with polymers containing biphenyl moieties, the glass transition temperatures of the polymers containing 1,3-dioxane moieties are lower, although their isotropization occurs at higher temperatures.     

Phase structures,transition behavior and surface alignment in polymers containing rigid rod-like backbones with flexible side chains, 3. The even-odd effect on phase transitions in combined liquid crystal polyesters

A series of "combined" liquid crystal (LC) polyesters consisting of aromatic main-chain backbones and flexible aliphatic side chains with 4-cyanobiphenyl end groups was synthesized based on the polycondensation of 2,2′-bis(trifluoromethyl)-4,4′-biphenyldicarbonyl chloride with 2,2′-bis{ω-[4-(4-cyanophenyl)phenoxy]-n-alkoxycarbonyl]}-4,4′-biphenyldiol (PEFBP). In a recent study of PEFBP(n = 11) containing eleven methylene units in the side chains, four different phases were identified in addition to the isotropic melt (I). They are as follows: an orthorhombic crystalline (K_O) phase, two triclinic crystalline (K_T1 and K_T2) phases in the high temperature region, and a nematic (N) phase. In this report, we focus on the even-odd effect of the methylene units in the side chains on the phase structure and transition behavior of PEFBP(n = 8, 9, 10 and 11)s. Two even-numbered PEFBPs with either eight or ten methylene units in the side chains [PEFBP(n = 10 and 8)s] were studied. An odd-numbered PEFBP containing nine methylene units, PEFBP(n = 9), was also investigated in addition to PEFBP(n = 11) which was reported on previously. It was found that both of the PEFBPs with even-numbered methylene units in their side chains [PEFBP(n = 10 and 8)s] exhibit only a nematic and a smectic A (S_A) phase. Their phase transition sequence during heating and cooling is T_g (S_A LC glass) ↔ S_A ↔ N ↔ I Since only LC phases exist, this is a thermodynamically reversible transition sequence independent upon thermal history. For PEFBP(n = 9 and 11)s, crystalline phases with three-dimensional order are observed above the NLC glass transition temperature in addition to the N phase. In PEFBP(n = 9), the N and K_O phases are similar to those seen in the case of PEFBP(n = 11). However, this polymer presents only one triclinic crystalline phase, while two triclinic crystal phases are observed in PEFBP(n = 11). The phase transition sequence in these odd-numbered PEFBPs during heating between 2.5°C/min –10°C/min for a sample cooled from the isotropic melt at the same rate is T_g (N LC glass) → K_O → N → K_T(s) → N → I Nevertheless, this sequence does not represent a case of thermodynamic equilibrium. The K_O and K_T(s) phases in PEFBP(n = 9 and 11)s and the S_A phase in PEBFP(n = 8 and 10)s are characteristics of the even-odd effect observed in this series of combined LC polyesters. The number of methylene units in the side chains thus plays a critical role in the formation of phase order and transition behavior in a way quite different from the common even-odd effect seen in main-chain LC polymers. Furthermore, this effect also indicates that the 4-cyanobiphenyl groups in the side chains are incorporated with the main-chain backbones to form the liquid crystal and crystal phases.     

Synthesis and characterization of novel side-chain liquid crystalline polycarbonates, 2. Polycondensation of mesogenic diols and diphosgene

A series of new side-chain liquid crystalline polymers was prepared with a polycarbonate backbone, bearing (E)-4′-nitrostilbene mesogenic groups, connected to the backbone by spacers of different length. The polymers were synthesized in 1,4-dioxane by polycondensation of diphosgene and diol monomers with the general structure 2-[ω-(4′-nitrostilben-4-ylcxy)alkyloxy]-1,3-propanediol in the presence of pyridine as a proton trap and catalyst. The mesomorphic properties of all monomers, polymers and intermediates were studied by polarized optical microscopy and differential scanning calorimetry (DSC). The polymers were also studied by X-ray diffraction of non-oriented and oriented samples (fibres). All monomers were liquid crystalline with nematic and/or smectic phases. For the polymers a clear relation was found between spacer length and glass transition temperature (T_g), which decreases with increasing spacer length and between spacer length and clearing temperature, which increases with increasing spacer length. X-ray diffraction measurements indicated the presence of a smectic A double layer structure (S_Ad) for all polymers at room temperature, with an antiparallel of overlapping mesogenic groups. A distinct difference in the orientation of the mesogens was found when fibres were drawn from the smectic phase or from the nematic or isotropic phase. In the first case the mesogenic groups were oriented perpendicular to the fibre axis and in the second case the mesogenic groups were oriented parallel to the fibre axis. By gel-permeation chromatography (GPC) measurements of heated samples and by thermogravimetric analysis (TGA) and DSC the polymers were found to be thermally stable up to temperatures well above their clearing point.     

Synthesis and phase behavior of side-chain liquid crystalline polymers with pendant quinoline rings bearing either a polar or a non-polar end group

Four methacrylate monomers, 2a–2d , containing a quinoline ring with a NO₂ or a OCH₃ group at the end of the mesogen were synthesized and polymerized. The copolymers with six methylene units as spacer, 3b–3d , showed a smectic phase induced by electron donor-acceptor interactions of the side groups. The homopolymer with eleven methylene units as spacer and methoxy end group, 3f , showed a smectic phase induced by the large length of the spacer. The copolymers with eleven methylene units, 3g–3i , showed a smectic phase induced by both the electron donor-acceptor interactions of the side groups and the large length of the spacer.     

Side-chain liquid-crystalline polymers containing a siloxane spacer, 1. Synthesis of side-chain liquid-crystalline polymers containing siloxane bond in the spacer unit

Side-chain liquid-crystalline polymers containing siloxane bond in the spacer units were prepared. For the synthesis of the desired monomers, novel silanol compounds carrying a mesogenic group were prepared as the intermediates. The polymers were obtained by ordinary free-radical polymerization. As the mesogenic groups, p- or p′-cyano-substituted biphenyl group, phenyl and biphenylyl benzoates were chosen, and the structural effects on the thermal properties were investigated. Introduction of a disiloxane group in the side chain resulted in a decrease of T_g which was more marked for longer siloxane units. Furthermore, only when a terphenylene-type mesogen was introduced, a stable smectic mesophase was observed with wide range of phase stability.     

Liquid-crystalline polyethers and copolyethers based on conformational isomerism, 4. Thermotropic polyethers and copolyethers based on 1-(4-hydroxyphenyl)-2-(2-methyl-4-hydroxyphenyl)ethane and flexible spacers containing an even number of methylene units

The synthesis and characterization of thermotropic main-chain liquid-crystalline polyethers MBPE-X and copolyethers MBPE-X/Y based on 3-methyl-4,4′-ethylenediphenol [1-(4-hydroxyphenyl)-2-(2-methyl-4-hydroxyphenyl)ethane (MBPE)], which is flexible rod-like mesogenic unit or a rod-like mesogenic unit based on conformational isomerism, and flexible spacers containing an even number of methylene units, X, Y, are described. The particular examples presented in this paper refer to polyethers MBPE-4, MBPE-6, MBPE-8, MBPE-10, and MBPE-12, and copolyethers MBPE-X/Y; where X,Y = 4, 6, 8, 10, 12. MBPE-4, MBPE-6, MBPE-10 and MBPE-12 are crystalline. MBPE-8 displays an enantiotropic nematic mesophase. Copolymerization of MBPE with different pairs of spacers containing even numbers of methylene units leads to MBPE-X/Y copolymers displaying monotropic or enantiotropic nematic mesophases. Both liquid-crystalline transition temperatures and the corresponding enthalpy changes of the copolymers represent weight-averaged values of the similar parameters of the parent homopolymers. Extrapolation of the isotropic-nematic and nematic-isotropic transition temperatures and their corresponding enthalpy changes demonstrated that all homopolymers containing an even number of methylene units in the flexible spacer exhibit virtual nematic mesophases. The virtual isotropic-nematic transition temperatures and the corresponding enthalpy changes were determined for MBPE-4, MBPE-6, MBPE-10 and MBPE-12. The virtual nematic-isotropic transition and the corresponding enthalpy changes could be determined only for MBPE-10 and MBPE-12.     

Synthesis and characterization of polymers containing 4-cyanobiphenyl-based side groups for nonlinear optical applications, 3. Poly(p-chloromethylstyrene) derivatives

Poly[p-(4′-cyanobiphenyl-4-yloxymethyl)styrene]s ( PCBMS ) were prepared by chemical modification of poly(p-chloromethylstyrene) with the sodium salt of 4-cyano-4′-hydroxybiphenyl or free radical polymerization of p-(4′-cyanobiphenyl-4-yloxymethyl)-styrene ( CBMS ). The latter method appeared to be a good one for the preparation of polymers with high glass transition temperature and high chromophore content if performed in dimethyl sulfoxide. There was no real evidence for liquid crystal properties in the resulting polymers, which resemble typical amorphous isotropic polymers. This indicates that these polymers should be considered to be polyethylene containing the benzyl ether of 4-cyano-4′-hydroxybiphenyl as the mesogenic group attached directly to the backbone, and not as polystyrenes containing the cyanobiphenyl group attached to the backbone through a ? O? CH₂? spacer. Some preliminary Corona poling experiments were performed, and the second harmonic generation coefficients d₃₁ and d₃₃, were measured by Maker fringe analysis. Interestingly, the ratio of d₃₃ to d₃₁ was found to be 6, which is much larger than the value of 3 predicted by the molecular statistical model for electric field poling of isotropic systems. This was attributed to conformational constraints on chromophore ordering as expected in such polymers containing no flexible spacer.     

Synthesis and characterization of a homologous series of chiral smectic C side-chain polymers

The synthesis and characterization of a homologous series of liquid-crystalline side-chain polymers with a chiral smectic C phase are described. The polymer backbone consists of methacrylate monomeric units which link the mesogenic moieties of the chiral cinnamic acid 2S- (?)-4-(2-chloro-4-methylpentanoyloxy)phenyl ester via a flexible spacer of six to eleven CH₂ groups. The influence of this variation on this variation on transition temperatures, phase structure and range of the l. c. phases is studied. In contrast to the monomers, the chiral smectic C phase of the polymers is significantly broadened with respect to the temperature regime and can be vitrified in the glassy state.     

Side chain liquid crystal polymers of 2,3-disubstituted norbornenes via ring-opening metathesis polymerization, 1 influence of flexible spacer length m = 2 to 12 on the thermotropic behaviour

Bis[(4′-cyanobiphenyl-4-yl)oxy-n-alkyl]norborn-5-ene-2,3-dicarboxylates with alkyl chain lengths m = 2 – 12 were synthesized. Most of the monomers exhibit thermodynamically metastable liquid crystalline phases with respect to the crystalline phases. Polymers were prepared by ring-opening metathesis polymerization (ROMP) using the molybdenum carbene initiator [Mo(CH-t-Bu) (NAr) (t-BuO)₂] (t-Bu = tert-butyl) with NAr = 2,6-diisopropylaniline. All polymers show thermotropic liquid crystalline phases. Results on characteristic phases and the influence of the number of methylene units m in the flexible spacer on the thermal behaviour (glass transition temperature, isotropization temperature, odd-even effect, enthalpy change) of these new side chain liquid crystal polymers (SCLCP's) are given. They are compared to monosubstituted polynorbornene derivatives and to SCLCP's with other backbones.     

Thermomechanical analysis of linear aromatic polyesters

The thermomechanical properties of linear aromatic polyesters, studied using thermomechanical analysis techniques, have been related to the chemical structure and methylene chain length. An increase in the number of methylene groups, the use of an asymmetric diacid, or random copolymerization of the repeating units of these polyesters, resulted in a lower linear thermal expansion coefficient α, a lower Vicat softening temperature T_s, a lower heat deflection temperature T_d, and a lower glass transition temperature T_g. With longer methylene sequence lengths, the influence of the methylene groups on the thermomechanical properties is predominant, the data are closer together. The values are generally highest for the terephthalate series and lowest for the copolymer series. Glass transition temperatures calculated from group contributions and measured experimentally agreed. The deflection temperatures approximated the glass transition temperatures and the Vicat softening points the melting temperatures.     

Liquid-crystalline polymers containing macrocyclic polyethers, 2. Side-chain liquid-crystalline copolysiloxanes containing mesogenic units based on 1,3-dioxane-2,5-diyl and benzo[15]-crown-5

Synthesis and characterization of a series of copolysiloxanes containing crown ether and trans-1,3-dioxane based mesogens are presented. The phase behaviour of the copolymers was studied using differential scanning calorimetry and optical polarizing microscopy and compared with the phase behaviour of the corresponding copolysiloxane-containing crown ether and biphenyl-based mesogens. Two copolysiloxanes containing trans-2-(benzo-[15]crown-5)-5-(ω-alkan-1-yloxy)-1,3-dioxane side groups present no liquid-crystalline behaviour. The other four copolysiloxanes exhibit a nematic mesophase and undergo side-chain crystallization at low temperature. Two of the four copolysiloxanes which contain a trans-1,3-dioxane-2,5-diyl group in the mesogenic unit present lower isotropization temperatures and narrower mesophase ranges than the other two. This result reveals that replacing a phenyl ring in the mesogenic unit of a liquid-crystalline polymer by a trans-1,3-dioxane ring will decrease the thermal stability of the mesophase exhibited by this polymer.     

Synthesis and non-linear optical characteristics of crosslinked and linear epoxy polymers with pendant tolane chromophores

Linear and crosslinked epoxy polymers containing high concentrations (ca. 86 wt.-%) of pendant 4-(4-nitrophenylethynyl)aniline [4-amino-4′-nitrotolane] chromophores were synthesized. They exhibit a smectic phase in the bulk once heated above the glass transition temperature (ca. 70°C). The appearance of the highly scattering smectic phase could be avoided by starting the crosslinking process of thin polymer films in the presence of solvent. Application of corona poling during crosslinking resulted in a highly polar polymer, exhibiting a very large birefringence of ca. 0,17 at 633 nm. Moreover, the birefringence remained stable during annealing at 80–90°C for ca. 30 days. The electro-optic coefficient, determined from the Pockels-effect, was roughly 8 pm/V for r₁₁₃ at 633 nm.     

Thermotropic liquid crystalline behaviour of pyridinium and poly(4-vinylpyridinium) salts quaternized with ω-alkyl phenylbenzoate derivatives

The synthesis, thermal properties and organisation of side-chain liquid-crystalline (SCLC) polysalts and of their analogous low molecular weight (LMW) pyridinium salts are described. They contain three distinct parts: a phenyl benzoate aromatic core, a flexible aliphatic chain (6 or 12 methylene units) and a pyridinium group associated with bromine counterions. The polysalts are obtained upon spontaneous anionic polymerisation of 4-vinylpyridine in the presence of 4-methoxyphenyl 4′-(ω-bromoalkoxy)benzoate. Fully quaternised polymers of high molecular weights are obtained. Their thermotropic polymorphism was studied by means of differential scanning calorimetry, polarising optical microscopy and X-ray diffraction. Despite the presence of the spacer and of a mesogenic group known for its nematogenic character, only smectic A mesophases were observed for the LMW pyridinium salt with the longer spacer (C₁₂) and for the polysalts with the two spacer lengths (C₆, C₁₂). These compounds were shown to form in a large range of temperature a single layered structure. An organisation model is proposed in which the pyridinium cations and the aromatic cores are perpendicular to the layer, while the spacers adopt a disorganised conformation.     

Synthesis and Properties of Novel Cardo Aromatic Poly(ether oxadiazole)s and Poly(ether‐amide oxadiazole)s

A series of polyhydrazides and poly(amide hydrazide)s bearing ether and cardo groups were prepared from three bis(ether carboxylic acid)s, 1,1‐bis[4‐(4‐carboxyphenoxy)phenyl]cyclohexane, 5,5‐bis[4‐(4‐carboxyphenoxy)phenyl]‐4,7‐methanohexahydroindan and 9,9‐bis[4‐(4‐carboxyphenoxy)phenyl]fluorene, or their diacyl chlorides with terephthalic dihydrazide, isophthalic dihydrazide and p‐aminobenzoyl hydrazide via the phosphorylation reaction or the low‐temperature solution polycondensation. The resulting hydrazide‐containing polymers exhibited inherent viscosities in the range of 0.35–0.71 dL·g^–1. All the hydrazide polymers were found to be amorphous as determined by X‐ray diffraction analysis and soluble in many organic polar solvents, and most of them afforded flexible and tough films by solvent casting. The hydrazide polymers had glass transition temperatures (T_g) between 157 and 197°C. All hydrazide polymers could be thermally converted into the corresponding oxadiazole polymers approximately in the region of 270–370°C, as evidenced by the DSC thermograms. The oxadiazole polymers showed a slightly enhanced crystallinity and an increase of T_g and a dramatically decreased solubility compared to their hydrazide prepolymers. They exhibited T_g's of 218–259°C and showed insignificant weight loss up to 450°C.     

Side-Chain liquid-crystalline polymers containing a siloxane spacer, 2. Effects of mesogenic groups on the thermal properties of side-chain liquid-crystalline polymers containing a disiloxane unit in the spacer

A series of side-chain Iiquid-crystalline polymers was prepared containing disiloxane units in the spacer. The polymers consist of a polymethacrylate backbone and several kinds of mesogenic side groups. For the synthesis of the desired monomers, silanol compounds carrying a mesogenic groups were prepared as the intermediates. The polymers were obtained by ordinary free-radical polymerization. As the mesogenic groups, linear-type p- or p′-substituted phenyl and biphenylyl benzoates, p- or m-substituted benzoyloxybiphenyl groups and laterally attached biphenylyl benzoate-type mesogens were chosen, and the structural effects on the thermal properties of the polymers were investigated. In the case of linear-type mesogens, only when triple-core mesogens were introduced a stable smectic mesophase was observed with a wide range of phase stability, while on mesophase was observed for the linear double-core and the laterally attached mesogens. On the other hand, a highly ordered smectic phase was observed for polymers having linear-type triple-core mesogens with p-alkoxy and m-cyano end groups. Furthermore, it was revealed that the introduction of a disiloxane unit in the spacer lowered the temperature range of the mesophase, in comparison with polymers having an alkylene spacer with the same backbone component and mesogens.     

Synthesis and Characterization of New Organosoluble Polyamides and Polyimides Based on 2,2‐Bis[4‐ (4‐aminophenoxy)‐3,5‐dimethylphenyl]‐ hexafluoropropane

A new hexafluoro‐containing diamine monomer, 2,2‐bis[4‐(4‐aminophenoxy)‐3,5‐dimethylphenyl]hexafluoropropane ( TBAPHP ), was synthesized in three steps, starting from hexafluoroacetone sesquihydrate and 2,6‐xylenol. The monomer was reacted with various aromatic dicarboxylic acids and tetracarboxylic dianhydrides to produce a series of polyamides and polyimides, respectively. The polyamides were prepared under Yamazaki reaction conditions. The polyimides were prepared by a two‐stage procedure that included a ring‐opening polyaddition yielding poly(amic acid)s, followed by a cyclodehydration to polyimides. The obtained polymers had inherent viscosities of 0.52–0.82 dL·g^–1. All of the polymers dissolved in polar solvents, such as N‐methyl‐2‐pyrrolidinone, N,N‐dimethylacetamide, and N,N‐dimethylformamide. The polyimides derived from 4,4′‐oxydiphthalic anhydride and 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride exhibited an excellent solubility and were dissolved in cyclohexanone, pyridine, tetrahydrofuran, and chloroform. These polymers showed glass transition temperatures of 231–301°C and decomposition temperatures at 10% weight loss ranging from 470 to 495°C in nitrogen and from 473 to 505°C in air. The tough and flexible polymer films obtained from solution casting showed tensile strengths of 78–96 MPa and tensile moduli of 2.0–2.4 GPa. Polymers containing methyl substituents had higher solubilities and T_g values than those without methyl substituents. In addition, the hexafluoroisopropylidene‐containing polymers exhibited a higher solubility and thermal stability than those containing isopropylidene units. UV‐visible absorption spectra revealed that the polyimides showed a better transparency than the polyamides.     

New poly(amide-imide)s syntheses, 14. Preparation and properties of poly(amide-imide)s based on 3, 3-bis[4-(4-trimellitimidophenoxy)phenyl]-1-oxoisoindoline

An imide ring-containing dicarboxylic acid, 3,3-bis[4-(4-trimellitimidophenoxy)phenyl]-1-oxoisoindoline, was prepared via condensation of 3,3-bis[4-(4-aminophenoxy)phenyl]-1-oxoisoindoline and trimellitic anhydride. A series of new aromatic bis(phenoxy)-1-oxo-isoindoline-containing poly(amide-imide)s were prepared via direct polycondensation of this diimide-diacid with various aromatic diamines using triphenyl phosphite and pyridine as condensing agents in N-methyl-2-pyrrolidone (NMP) in the presence of calcium chloride. Most of the resulting polymers are of amorphous nature and readily soluble in polar solvents such as NMP and N,N-dimethylacetamide. All soluble poly(amide-imide)s afford transparent, flexible, and tough films. The glass transition temperatures of the polymers are in the range of 267–305°C and show almost no weight loss up to 450°C in nitrogen atmosphere. The properties of 1-oxoisoindoline containing poly(amide-imide)s are compared with those of the corresponding analogous poly(amide-imide)s derived from 3,3-bis[4-(4-trimellitimidophenoxy)phenyl]phthalide.     

Relation between structure and thermal transitions in comb-like polymers, 1. Poly(N-n-alkylmaleimide)s

A series of nine poly(N-n-alkylmaleimide)s (PMIs) with the n-alkyl side chain ranging in length from ethyl to octadecyl and including only the even members of the series was studied by differential scanning calorimetry (DSC) from 100 K to above the glass transition temperature. The nine members of the PMI series generally were found to exhibit a glass transition temperature (T_g), a sub-glass transition temperature (sub-T_g = T_γ), and, but only the four higher homologs a melting point (T_m) with the respective melting enthalpy (ΔH_f). The glass transition of the amorphous members is directly related to the number of methylene groups (including terminal methyl) of the n-alkyl side chain of the repeating unit. The values of T_g estimated according to a semi-empirical equation are in good agreement with the experimental data. The melting points of the members of the series presenting crystallinity in the n-alkyl side chain were analyzed. A good fit of a Garner plot by a least-mean-squares procedure is obtained with T = 408,0K, a = ?6,26 and b = ?2,03. The contribution to the heat of melting per methylene unit clearly demonstrates that the hexagonal paraffin crystal structure is present in the crystalline members, in agreement with X-ray data. The data when analyzed by Jordan′s procedure show that only part of the n-alkyl side chain is forming a crystal lattice.