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  <xs:element id="wlk_NumberOfMultiemployerPlans" abstract="false" name="NumberOfMultiemployerPlans" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="wlk_RatablyOnAnnualBasisMember" abstract="true" name="RatablyOnAnnualBasisMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_CliffVestMember" abstract="true" name="CliffVestMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_WeightedAverageRemainingTermYearsAbstract" abstract="true" name="WeightedAverageRemainingTermYearsAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="wlk_AggregateIntrinsicValueAbstract" abstract="true" name="AggregateIntrinsicValueAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="wlk_RangeOneMember" abstract="true" name="RangeOneMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_RangeTwoMember" abstract="true" name="RangeTwoMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_RangeThreeMember" abstract="true" name="RangeThreeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_RangeFourMember" abstract="true" name="RangeFourMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_RangeFiveMember" abstract="true" name="RangeFiveMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_ScheduleOfShareBasedPaymentAwardPerformanceShareUnitsValuationAssumptionsTable" abstract="true" name="ScheduleOfShareBasedPaymentAwardPerformanceShareUnitsValuationAssumptionsTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="wlk_ScheduleOfShareBasedPaymentAwardPerformanceShareUnitsValuationAssumptionsLineItems" abstract="true" name="ScheduleOfShareBasedPaymentAwardPerformanceShareUnitsValuationAssumptionsLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="wlk_ShareBasedCompensationArrangementsExpectedVolatilityRateofPeerCompanies" abstract="false" name="ShareBasedCompensationArrangementsExpectedVolatilityRateofPeerCompanies" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="wlk_ShareBaseCompensationAverageCorrelationCoefficientofPeerCompanies" abstract="false" name="ShareBaseCompensationAverageCorrelationCoefficientofPeerCompanies" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:pureItemType"/>
  <xs:element id="wlk_EffectiveIncomeTaxRateReconciliationUncertainIncomeTaxPositions" abstract="false" name="EffectiveIncomeTaxRateReconciliationUncertainIncomeTaxPositions" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_DeferredTaxAssetsOperatingLeaseLiabilities" abstract="false" name="DeferredTaxAssetsOperatingLeaseLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_DeferredTaxLiabilitiesOperatingLeaseRightofUseAssets" abstract="false" name="DeferredTaxLiabilitiesOperatingLeaseRightofUseAssets" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_DeferredTaxLiabilitiesParentsBasisInConsolidatedPartnerships" abstract="false" name="DeferredTaxLiabilitiesParentsBasisInConsolidatedPartnerships" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_ValuationAllowanceAdditionalAllowances" abstract="false" name="ValuationAllowanceAdditionalAllowances" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_ValuationAllowanceReversalsAndOtherChanges" abstract="false" name="ValuationAllowanceReversalsAndOtherChanges" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_OperatingLossCarryforwardExpirationStatusAxis" abstract="true" name="OperatingLossCarryforwardExpirationStatusAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="wlk_OperatingLossCarryforwardExpirationStatusDomain" abstract="true" name="OperatingLossCarryforwardExpirationStatusDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_SubjectToExpirationMember" abstract="true" name="SubjectToExpirationMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_NotSubjectToExpirationMember" abstract="true" name="NotSubjectToExpirationMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_NetIncomeLossAvailableToCommonStockholders" abstract="false" name="NetIncomeLossAvailableToCommonStockholders" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_EnvironmentalRemediationAndOtherPlantMothballingCostsMember" abstract="true" name="EnvironmentalRemediationAndOtherPlantMothballingCostsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_AssetRetirementObligationsMember" abstract="true" name="AssetRetirementObligationsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_InventoryWriteDownMember" abstract="true" name="InventoryWriteDownMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_ContractTerminationCostsMember" abstract="true" name="ContractTerminationCostsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_AcceleratedDepreciationAndAmortizationMember" abstract="true" name="AcceleratedDepreciationAndAmortizationMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_HexionMember" abstract="true" name="HexionMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_PernisFacilityClosureMember" abstract="true" name="PernisFacilityClosureMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_ChlorovinylsAndStyreneFacilityClosureMember" abstract="true" name="ChlorovinylsAndStyreneFacilityClosureMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_HuasuPVCUnitMember" abstract="true" name="HuasuPVCUnitMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_OtherForeignCountriesMember" abstract="true" name="OtherForeignCountriesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_ContractWithCustomerLiabilityPaymentAdvance" abstract="false" name="ContractWithCustomerLiabilityPaymentAdvance" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_ContractWithCustomerLiabilityIncreaseForCashReceived" abstract="false" name="ContractWithCustomerLiabilityIncreaseForCashReceived" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_AccruedRebatesCurrent" abstract="false" name="AccruedRebatesCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_NonCashInvestingActivityAbstract" abstract="true" name="NonCashInvestingActivityAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="wlk_ProductionFacilityAnnualCapacitySuspensionPVC" abstract="false" name="ProductionFacilityAnnualCapacitySuspensionPVC" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:weightItemType"/>
  <xs:element id="wlk_ProductionFacilityAnnualCapacityVCM" abstract="false" name="ProductionFacilityAnnualCapacityVCM" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:weightItemType"/>
  <xs:element id="wlk_ProductionFacilityAnnualCapacityChlorine" abstract="false" name="ProductionFacilityAnnualCapacityChlorine" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:weightItemType"/>
  <xs:element id="wlk_ProductionFacilityAnnualCapacityCausticSoda" abstract="false" name="ProductionFacilityAnnualCapacityCausticSoda" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:weightItemType"/>
  <xs:element id="wlk_ProductionFacilityAnnualCapacityStyrene" abstract="false" name="ProductionFacilityAnnualCapacityStyrene" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:weightItemType"/>
  <xs:element id="wlk_PensionGainOther" abstract="false" name="PensionGainOther" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_CypressInterstatePipelineLLCMember" abstract="true" name="CypressInterstatePipelineLLCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_YNCORISGmbHCo.KGMember" abstract="true" name="YNCORISGmbHCo.KGMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_WestlakeUVCoatingsShanghaiCoLtdMember" abstract="true" name="WestlakeUVCoatingsShanghaiCoLtdMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_AmericanAirLiquideHoldingsMember" abstract="true" name="AmericanAirLiquideHoldingsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_PipelineFeesForTransportOfNaturalGasLiquidFeedstocksMember" abstract="true" name="PipelineFeesForTransportOfNaturalGasLiquidFeedstocksMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_ElectricityAndTechnicalServicesMember" abstract="true" name="ElectricityAndTechnicalServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_OfficeLeaseExpense" abstract="false" name="OfficeLeaseExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_PurchasesAndLeaseExpense" abstract="false" name="PurchasesAndLeaseExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_WestlakeChemicalPartnersLPMember" abstract="true" name="WestlakeChemicalPartnersLPMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_TTWFLPMember" abstract="true" name="TTWFLPMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_LimitedPartnershipOwnershipPercentageIncrease" abstract="false" name="LimitedPartnershipOwnershipPercentageIncrease" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="wlk_PartnersUnitsMaximumAggregateOfferingAmountATM" abstract="false" name="PartnersUnitsMaximumAggregateOfferingAmountATM" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_CausticSodaAntitrustProceedingsMember" abstract="true" name="CausticSodaAntitrustProceedingsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_EthyleneAntitrustLitigationProceedingsMember" abstract="true" name="EthyleneAntitrustLitigationProceedingsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_BrazilianContractualIndemnificationLawsuitMember" abstract="true" name="BrazilianContractualIndemnificationLawsuitMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_CalvertCityProceedingsMember" abstract="true" name="CalvertCityProceedingsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_SulphurBrineDomeMember" abstract="true" name="SulphurBrineDomeMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_LitigationPlaintiffsAxis" abstract="true" name="LitigationPlaintiffsAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="wlk_LitigationPlaintiffsDomain" abstract="true" name="LitigationPlaintiffsDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_DirectPurchasersMember" abstract="true" name="DirectPurchasersMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_IndirectPurchasersMember" abstract="true" name="IndirectPurchasersMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_LitigationSettlementLegalFeeAndProceduralFinePercentage" abstract="false" name="LitigationSettlementLegalFeeAndProceduralFinePercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="wlk_NumberOfPlants" abstract="false" name="NumberOfPlants" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="wlk_ConcentrationRiskNumberOfMajorCustomers" abstract="false" name="ConcentrationRiskNumberOfMajorCustomers" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="wlk_PerformanceMaterialsMember" abstract="true" name="PerformanceMaterialsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_EssentialMaterialsMember" abstract="true" name="EssentialMaterialsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_HousingProductsMember" abstract="true" name="HousingProductsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_InfrastructureProductsMember" abstract="true" name="InfrastructureProductsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="wlk_RawMaterialEnergyAndManufacturingCosts" abstract="false" name="RawMaterialEnergyAndManufacturingCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_DepreciationAndAmortizationSegmentExpenses" abstract="false" name="DepreciationAndAmortizationSegmentExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_LogisticsCosts" abstract="false" name="LogisticsCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_SellingGeneralAndAdministrativeExpenses" abstract="false" name="SellingGeneralAndAdministrativeExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_DepreciationAndAmortizationSGA" abstract="false" name="DepreciationAndAmortizationSGA" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_ImpairmentOfGoodwillAndLongLivedAssets" abstract="false" name="ImpairmentOfGoodwillAndLongLivedAssets" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_RestructuringTransactionAndIntegrationRelatedCosts" abstract="false" name="RestructuringTransactionAndIntegrationRelatedCosts" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_TotalSellingGeneralAndAdministrativeExpenses" abstract="false" name="TotalSellingGeneralAndAdministrativeExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="wlk_ACIMember" abstract="true" name="ACIMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
